Safety Standard for Lithium-Ion Batteries Used in Micromobility Products and Electrical Systems of Micromobility Products Containing Such Batteries

Federal RegisterJun 24, 2026

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CONSUMER PRODUCT SAFETY COMMISSION

16 CFR Parts 1112 and 1265

[CPSC Docket No. CPSC-2025-0012]

RIN 3041-AE10

Safety Standard for Lithium-Ion Batteries Used in Micromobility Products and Electrical Systems of Micromobility Products Containing Such Batteries

AGENCY:

Consumer Product Safety Commission.

ACTION:

Notice of proposed rulemaking.

SUMMARY:

The U.S. Consumer Product Safety Commission (CPSC) issues this notice of proposed rulemaking (NPR) to address the unreasonable risk of death and injury associated with lithium-ion batteries used in micromobility products due to hazards such as thermal runaway of lithium cells, which can lead to fires, explosions, gas releases, burns, overheating, and smoke inhalation. The NPR proposes that electrical systems using lithium-ion batteries in micromobility products comply with applicable voluntary standards, with modifications. Because some micromobility products are children's products requiring third party testing, the NPR also proposes to add this rule to the list of rules that require such testing.

DATES:

Deadline for Written Comments:

Written comments on the NPR or the Paperwork Reduction Act (PRA) must be received by August 24, 2026.

Deadline for Request to Present Oral Comments:

Any person interested in making an oral presentation must send an email indicating this intent to the Office of the Secretary at

cpsc-os@cpsc.gov

by July 24, 2026.

ADDRESSES:

Submit comments, identified by Docket No. CPSC-2025-0012, by any of the following methods:

Electronic Submissions:

Submit electronic comments to the Federal eRulemaking Portal at:

https://www.regulations.gov.

Follow the instructions for submitting comments. CPSC typically does not accept comments submitted by email, except through

www.regulations.gov.

CPSC encourages you to submit electronic comments by using the Federal eRulemaking Portal, as described above.

Mail/Hand Delivery/Courier/Confidential Written Submissions:

Submit comments by mail, hand delivery, or courier to: Office of the Secretary, Consumer Product Safety Commission, 4330 East-West Highway, Bethesda, MD 20814; (301) 504-7479. If you wish to submit confidential business information, trade secret information, or other sensitive or protected information that you do not want to be available to the public, you may submit such comments by mail, hand delivery, or courier, or you may email them to:

cpsc-os@cpsc.gov.

Instructions:

All submissions must include the agency name and docket number. CPSC may post all comments without change, including any personal identifiers, contact information, or other personal information provided, to

https://www.regulations.gov.

Do not submit through this website: Confidential business information, trade secret information, or other sensitive or protected information that you do not want to be available to the public. If you wish to submit such information, please submit it according to the instructions for mail/hand delivery/courier/confidential written submissions.

Docket:

For access to the docket to read background documents, a plain language summary of the proposed rule, or comments received, go to:

https://www.regulations.gov,

and insert the docket number, CPSC-2025-0012, into the “Search” box, and follow the prompts.

FOR FURTHER INFORMATION CONTACT:

Jay Kadiwala, Project Manager, Electrical Engineer, Office of Risk Reduction, Consumer Product Safety Commission, National Product Testing and Evaluation Center, 5 Research Place, Rockville, MD 20850; telephone: (301) 987-2517;

jkadiwala@cpsc.gov.

SUPPLEMENTARY INFORMATION:

I. Introduction

The increasing use of micromobility products powered from multi-cell lithium-ion rechargeable batteries is a growing safety concern because of the potential for deadly smoke and fires that can spread beyond the product. For the purposes of this NPR, a “micromobility product” includes the following lithium-ion battery-powered vehicles, where “e” represents “electric”: eBikes, eScooters,

self-balancing scooters (such as Hoverboards; eSBscooters), eSkateboards, eUnicycles, and hybrids of these micromobility products within CPSC's jurisdiction.

Includes both stand-up and seated eScooters.

As explained in detail in section III of this preamble, over a five-year period from 2019 through 2023, CPSC is aware of 227 unique incidents—involving fires, explosions, gas releases, burns, overheating, and smoke inhalation—that potentially could have been prevented by this proposed rule; 90 incidents are associated with 39 fatalities and 181 injuries, and 39 out of the 227 incidents involved multiple deaths and injuries. Thus, consumers of micromobility products may be exposed to risks of injury or death from these products. Consequently, the Commission is issuing this NPR to address the unreasonable risk of death and injury associated with lithium-ion batteries used in micromobility products and their electrical systems.

A. Overview of the Proposed Rule

In this NPR,

the Commission proposes to regulate lithium-ion batteries used in micromobility products and the electrical systems of micromobility products containing such batteries, including all components that make up an electrical system, such as lithium-ion batteries, battery management systems (BMS), chargers, and any other electrical component addressed in the applicable voluntary standard, collectively, “micromobility electrical systems.” In addition to original equipment manufacturer (OEM) lithium-ion batteries sold with a micromobility product, the NPR proposes to regulate lithium-ion batteries for use in micromobility products but sold separately from the micromobility product (termed “user replaceable battery packs”), including components sold in eBike electrical system conversion kits.

This NPR is based on the information and analysis contained in this NPR and in the January 8, 2025, Staff Briefing Memorandum: Draft Proposed Rule to Establish a Safety Standard for Lithium-Ion Batteries Used in Micromobility Products and Electrical Systems of Micromobility Products Containing Such Batteries (Staff's NPR Briefing Memo); available at:

https://www.cpsc.gov/s3fs-public/Decisional-Package-Draft-Proposed-Rule-to-Establish-a-Safety-Standard-for-Lithium-Ion-Batteries-and-Micromobility-Products.pdf?VersionId=Ob0VAPOfK5iRbXyKJ8SxqwR9SXLkxOnS.

On March 26, 2025, CPSC staff sent corrections to the draft proposed rule to the Commission, available at:

https://www.cpsc.gov/s3fs-public/Package-Corrections-to-Draft-Proposed-Rule-to-Establish-a-Safety-Standard-for-Lithium-Ion-Batteries.pdf?VersionId=fhpnWvJVNIRL1dMRP3ByUYel0xPJf_kH.

Based on the incident data and analysis presented in this NPR, the Commission preliminarily determines that micromobility electrical systems, user replaceable battery packs sold separately from a micromobility product, aftermarket battery chargers sold separately from a micromobility product, and components for eBike conversion kits, present an unreasonable risk of injury and death to consumers from electric shock, fires, explosions, expulsion of gas or flames, burns, overheating, and smoke inhalation (collectively the “associated

hazards”) if they are not compliant with the requirements of this NPR. Particularly, hazards associated with “thermal runaway,” which is a self-sustaining internal cell chemical reaction that results in the rapid generation of heat that ignites the flammable electrolyte, can lead to serious injury and death. Thermal runaway occurs when burning hot gases create pressure that can cause flaming materials and gases to be ejected from the cell casing, resulting in an explosion and/or fire. The intense fire can in turn induce thermal runaway in adjacent cells and ignite combustible materials near the battery.

Additionally, the products within the scope of this proposed rule may present a risk of electric shock where voltages are at or greater than 42.4 peak VAC (volts alternating current) or 60 VDC (volts direct current). CPSC staff have not identified electric shock incidents involving micromobility products. However, at this time, the majority of micromobility product batteries are rated below 60 VDC and do not present a shock hazard from the battery. As micromobility products become more powerful and extend the range of operation, battery packs may exceed 60 VDC and can present a shock hazard that could result in serious injury or death. Further, chargers (both external and those integrated into the micromobility product) are powered from 120 VAC utility power and can present a shock hazard that could result in serious injury or death.

To address the unreasonable risks of injury associated with lithium-ion batteries used in micromobility products and their electrical systems, the NPR proposes that each product within the scope of the rule meet the performance requirements in the applicable voluntary standard, with modifications as described in sections IV and V of this preamble:

• ANSI/CAN/UL 2849:2020,

Standard for Safety for Electrical Systems for eBikes

(UL 2849-20) (eBikes);

• ANSI/CAN/UL 2272:2024,

Standard for Safety for Electrical Systems for Personal E-Mobility Devices

(UL 2272-24) (eScooters, eSBscooters, eSkateboards, eUnicycles, and hybrid products, collectively “other micromobility products,” or “personal eMobility products” (OMPs)); and

• ANSI/CAN/UL/ULC 2271:2023,

Standard for Safety for Batteries for Use in Light Electric Vehicle (LEV) Applications

(UL 2271-23) (user replaceable battery packs).

Section IV of this preamble evaluates performance and labeling requirements in the voluntary standards and their ability to eliminate or adequately reduce the hazards associated with lithium-ion batteries and micromobility product electrical systems. CPSC's analysis finds that, overall, the performance requirements in UL 2849-20, UL 2272-24, and UL 2271-23 are inadequate to eliminate or adequately reduce the unreasonable risks of injury, because the performance requirements do not address all identified hazards associated with lithium-ion batteries and micromobility product electrical systems. Accordingly, the NPR proposes the following modifications to performance requirements to adequately reduce the associated hazards, including:

• Adding to UL 2849-20 and UL 2271-23 tamper-resistant battery enclosure requirements from UL 2272-24 to reduce the risk of injury associated with consumers accessing the battery pack;

• Adding to UL 2849-20 and UL 2271-23 post-discharge charge test requirements from UL 2272-24 to reduce the risk of injury by ensuring that the BMS prohibits charging the battery if the cell surface temperature exceeds the specified upper limit;

• Adding to UL 2849-20, UL 2272-24, and UL 2271-23, a reverse polarity test to reduce the risk of injury by preventing damage to the battery pack due to use of an incompatible charger.

The NPR also proposes that labeling requirements be revised in each of the three voluntary standards, UL 2849-20, UL 2271-23, and UL 2272-24, for all products within the scope of the rule, to adequately reduce the risk of injury associated with foreseeable consumer use and misuse of lithium-ion batteries and micromobility electrical systems by improving safety messaging addressing electric shock and thermal runaway, and additional identified hazard patterns such as homemade batteries and unsafe battery charging.

As discussed in section IV of this preamble, micromobility products as a whole do not substantially comply with the applicable voluntary standards. Accordingly, the NPR proposes that products within the scope of the rule meet the requirements in applicable voluntary standards, as they are proposed to be modified.

B. Background and Statutory Authority

The Commission proposes this NPR under sections 7 and 9 of the Consumer Product Safety Act (CPSA). 15 U.S.C. 2056 and 2058. Section 7(b)(1) of the CPSA requires the Commission to rely on a voluntary standard, rather than promulgate a mandatory standard, when product compliance with the voluntary standard would eliminate or adequately reduce the risk of injury associated with a product, and it is likely that products are in substantial compliance with the voluntary standard. 15 U.S.C. 2056(b)(1). As explained in section IV of this preamble, the Commission preliminarily determines that the applicable voluntary standards are inadequate to fully address the risks of injury from associated hazards, including thermal runaway, for products within the scope of the rule, and that overall, micromobility products do not substantially comply with the applicable voluntary standards.

Section 9 of the CPSA specifies the procedure the Commission must follow to issue a consumer product safety standard under section 7 of the CPSA. Section 9 authorizes the Commission to issue an NPR, which includes a proposed rule and a preliminary regulatory analysis, in accordance with section 9(c) of the CPSA. 15 U.S.C. 2058(c). We request comments from the public regarding the associated hazard patterns and risks of injury identified by the Commission in section III of this preamble, the regulatory alternatives being considered, and other possible alternatives for addressing the risks discussed in sections III and VI of this preamble. By statute, the preliminary regulatory analysis must include:

• a preliminary description of the potential benefits and potential costs of the proposed rule, including any benefits or costs that cannot be quantified in monetary terms, and an identification of those likely to receive the benefits and bear the costs;

• a discussion of applicable voluntary standards;

• a description of any reasonable alternatives to the proposed rule, together with a summary description of their potential costs and benefits, and a brief explanation of why such alternatives should not be published as a proposed rule.

Id.

Tab A of Staff's January 8, 2025, NPR Briefing Memo and section VI of this preamble provide the required preliminary regulatory analysis for a mandatory standard.

After issuing an NPR, the Commission will consider the comments received in response to the NPR and decide whether to issue a final rule, along with a final regulatory analysis. 15 U.S.C. 2058(c)-(f). If requested by commenters, the Commission also will provide an opportunity for interested persons to make oral presentations of data, views, or arguments, in accordance with section 9(d)(2) of the CPSA. 15 U.S.C. 2058(d)(2).

According to section 9(f)(1) of the CPSA, before promulgating a consumer product safety rule, the Commission must consider, and make appropriate findings to be included in the rule, on the following issues:

• The degree and nature of the risk of injury that the rule is designed to eliminate or reduce;

• The approximate number of consumer products subject to the rule;

• The need of the public for the products subject to the rule and the probable effect the rule will have on utility, cost, or availability of such products; and

• The means to achieve the objective of the rule while minimizing adverse effects on competition, manufacturing, and commercial practices.

15 U.S.C. 2058(f)(1). At the NPR stage, the Commission is making these findings preliminarily to allow the public to comment on the findings. Appendix A to the proposed regulation text contains the Commission's proposed findings.

Under section 9(f)(3) of the CPSA, to issue a final rule, the Commission must find that the rule is “reasonably necessary to eliminate or reduce an unreasonable risk of injury associated with such product” and that issuing the rule is in the public interest. 15 U.S.C. 2058(f)(3)(A)-(B). Additionally, if a voluntary standard addressing the risk of injury has been adopted and implemented, the Commission must find that:

• The voluntary standard is not likely to eliminate or adequately reduce the risk of injury, or

• Substantial compliance with the voluntary standard is unlikely.

15 U.S.C. 2058(f)(3)(D). The Commission also must find that the expected benefits of the rule bear a reasonable relationship to its costs and that the rule imposes the least burdensome requirements that would adequately reduce the risk of injury. 15 U.S.C. 2058(f)(3)(E)-(F). As set forth in section XIV of this preamble, the Commission at this time makes preliminary findings on these requirements.

C. CPSC's Jurisdiction Over Micromobility Products

Under the CPSA, CPSC has jurisdiction over “consumer products,” which includes their component parts. 15 U.S.C. 2052(a)(5). The definition of a “consumer product” under the CPSA excludes medical devices under the Federal Food and Drug Administration's (FDA) jurisdiction; articles which are not customarily produced or distributed for sale to, or use or consumption by, or enjoyment of, a consumer; products where a risk of injury could be eliminated or reduced to a sufficient extent by actions taken under the Occupational Health and Safety Act; and “motor vehicles” and “motor vehicle equipment” as defined in the National Traffic and Motor Vehicle Safety Act of 1966. 15 U.S.C. 2052(a)(5)(A) and (C), 2080(a); 49 U.S.C. 30102. A “motor vehicle” is “a vehicle driven or drawn by mechanical power and manufactured primarily for use on public streets, roads, and highways, but does not include a vehicle operated only on a rail line.” 49 U.S.C. 30102. Accordingly, CPSC has jurisdiction over any micromobility product that is not a “motor vehicle” under the jurisdiction of the National Highway Traffic Safety Administration (NHTSA). CPSC's jurisdiction includes commercially owned micromobility products that are used by consumers, for instance in rental fleets.

See

47 U.S.C. 2052(a)(5) (defining “consumer product” to include products “produced or distributed . . . for the personal use, consumption or enjoyment of a consumer in or around a permanent or temporary household or residence, a school, in recreation, or otherwise”).

Thus, CPSC has jurisdiction over products such as racing bikes, dirt bikes, all-terrain vehicles (ATVs), scooters, bikes, and skateboards.

In contrast to these products, motor vehicles intended for on-road use generally have features such as a Vehicle Identification Number (VIN), as well as other on-road capabilities which may include head lights, taillights, brake lights, and side mirrors.

When jurisdictional issues arise, CPSC staff discuss specific products with NHTSA staff.

Congress specifically stated CPSC's jurisdiction over low-speed bicycles, which is implemented in CPSC's bicycle regulations. 15 U.S.C. 2085; 16 CFR 1512.2(a)(2). In addition, pedal-assisted eBikes that are not capable of continued self-propulsion fall within CPSC's jurisdiction.

See, for example,

NHTSA's guidance at:

https://www.nhtsa.gov/interpretations/07-001825as.

See https://www.nhtsa.gov/importing-vehicle/importation-and-certification-faqs-0.

II. Micromobility Products Within the Scope of the Rule

A. Description of Micromobility Products

The Commission proposes to regulate lithium-ion batteries used in micromobility products and the electrical systems of micromobility products containing such batteries, including six types of micromobility products: eBikes, eScooters, eSBscooters, eSkateboards, eUnicycles, and hybrids of these products. Figure 1 shows examples of these micromobility products.

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Generally, micromobility products are marketed, intended, and designed for recreational off-road use and for transportation in urban and suburban areas, typically for short distances. Micromobility products rely on one or more wheels driven by electric motors that receive electrical power from a rechargeable lithium-ion battery, via a motor control circuit, to start and stop the product and control its speed. The type of micromobility product dictates how a user rides and controls the product. This NPR proposes to address electrical hazards associated with all micromobility products subject to UL 2849-20 and UL 2272-24, as defined in the standards, but excludes products that are not within CPSC's jurisdiction.

This NPR also includes user replaceable battery packs subject to UL 2271-23, which are sold separately for use in micromobility products within the scope of this proposed rule.

Lithium battery-powered motive products that are not micromobility products are excluded from the scope of this proposed rule including children's battery-powered ride-on toys (defined in 16 CFR part 1250), ATVs (defined in 16 CFR part 1420), Recreational Off-Highway Vehicles (defined in ANSI/ROHVA 1-2023), Multipurpose Off-Highway Utility Vehicles (defined in ANSI/OPEI B71.9-2022), and Golf Cars (defined in ANSI/ILTVA Z130.1).

UL 2849-20 addresses electrical hazards associated with eBikes. All other micromobility products covered by this NPR, including eScooters, eSBscooters, eSkateboards, eUnicycles, and hybrids of these products (collectively, OMPs or personal eMobility products), are defined in section 6.25 of UL 2272-24 as a “Personal E-Mobility Device- [a] consumer mobility device intended for a single rider with a rechargeable

electric drive train that balances and propels the rider, and which may be provided with a handle for grasping while riding, but excludes motorized wheelchairs including mobility scooters for medical purposes. This device may or may not be self-balancing.” This section describes products within the scope of this NPR.

For more information on the generic physical design of micromobility products and common differentiating features,

see

Society of Automotive Engineers International (SAE) J3194, Taxonomy & Classification of Powered Micromobility Vehicles (SAE J3194).

eBikes

—Section 5.4 of UL 2849-20 defines an “eBike” as “[a] two or three wheeled electrical/mechanical device provided with functional pedals that includes one or more electric motors to either assist the rider when pedaling (in Electrically Power Assisted Cycle (EPAC) versions) or provide motive power to the wheels when the rider is not pedaling.”

As shown in Figure 1, most eBikes have two wheels with tubed rubber tires that are inline, a seat for a rider, and handlebars for steering the front wheel while power is applied to the rear tire. When the rider pedals an EPAC eBike, a charged onboard battery pack supplies electrical power to a motor that “assists” the rider by reducing the mechanical energy required from the rider to apply a given force to the drivetrain. In this product, the battery pack is generally user replaceable, meaning that it can be removed from the eBike for charging. When the electrical system is not engaged, an EPAC eBike functions as a traditional non-powered bicycle.

Bicycles are subject to an existing product safety regulation, 16 CFR part 1512. In March 2024, the Commission issued an advance notice of proposed rulemaking for mechanical hazards related to eBikes. 89 FR 18861 (Mar. 15, 2024).

Traditional bicycles, as well as some eBikes, are subject to the mechanical requirements set forth in 16 CFR part 1512. The scope of part 1512 includes: (a) two-wheeled bikes whose rear drive wheel is solely human-powered, and (b) two- or three-wheeled bikes with operable pedals, an electric motor of less than 750 watts, and a powered maximum speed on a paved level surface less than 20 miles per hour (mph) when being ridden by a person weighing 170 pounds. 16 CFR 1512.2(a). All lithium-powered eBikes that fall within the scope of § 1512.2(a)(2) are also included within the scope of this NPR, because part 1512 regulates mechanical hazards and this NPR proposes to regulate electrical hazards associated with such eBikes. This rule also includes eBikes that exceed the wattage, speed, and weight limits set forth in § 1512.2(a)(2), as long as the product is not a motor vehicle or otherwise outside the Commission's jurisdiction.

eScooters

—UL 2272-24 addresses electrical hazards associated with eScooters. As shown in Figure 1, stand-up eScooters have two inline wheels with a long flat platform between the wheels where the rider places their feet. The rider places one foot in front of the other and is generally in a standing position with their hands on the handlebars to steer the front wheel. A sit-down eScooter looks much like a bicycle but does not have functional pedals. An eScooter battery pack can be either integral to the product or user replaceable. Riders generally control an eScooter's speed using a hand-controlled throttle, and eScooter braking can be actuated either electrically or manually.

eSBscooters

—UL 2272-24 addresses electrical hazards associated with eSBscooters. As shown in Figure 1, eSBscooters are battery-powered scooters having two foot pads that are side-by-side with one driven wheel on each side of each foot pad. Battery packs are typically integral to eSBscooters but may be user replaceable. The rider generally controls the scooter by slight tilting of one or both feet or shifting their body weight to angle one or both footpads slightly downward to propel the scooter; eSBscooters generally do not have a handlebar or use hand controls to steer the scooter. Accordingly, eSBscooters require the rider to have the ability to balance on the scooter to effectively steer and operate the product.

eSkateboards

—UL 2272-24 addresses electrical hazards associated with battery-powered skateboards. eSkateboards are like traditional non-powered skateboards, except they have a motor powered by a lithium-ion battery pack mounted underneath the foot platform. Riders typically operate eSkateboards using a remote control, but some eSkateboards operate using only body weight, by leaning to one side of the eSkateboard to control both direction and speed. eSkateboards do not have a handlebar.

eUnicycles

—UL 2272-24 addresses electrical hazards associated with eUnicycles, shown in Figure 1. eUnicycles, generally powered by one or two lithium-ion battery packs, have one wheel that sits between the rider's feet. To ride, the user stands on two foldable metal flaps on opposite sides of the wheel. The rider causes an eUnicycle to move by leaning forward slightly on the product to propel forward motion.

Hybrid micromobility products

—Hybrid micromobility products that fall within the scope of UL 2272, and are not excluded from CPSC's jurisdiction, are within the scope of this NPR. UL 2272-24 addresses electrical hazards associated with micromobility products that are a hybrid design and do not fit squarely within the product descriptions for eScooter, eSBscooter, eSkateboard, and eUnicycle. Examples of hybrid micromobility products within the scope of the NPR include eSBscooters with handlebars or leg bars and eSkateboards with a long platform and one large wheel in the center of the platform, rather than four small wheels. eSBscooters with handlebars or leg bars allow the rider to steer and more easily shift body weight to propel the product forward. Riders mount an eSkateboard with one wheel with feet positioned one in front of the wheel and one foot behind the wheel; the rider's body lean controls the angle, speed, and direction of movement.

Lithium-ion Batteries

—Section II.B.3 of this preamble describes user replaceable lithium-ion battery packs, both OEM and third party, within the scope of UL 2271-23 and this proposed rule. OEM batteries that are sold with a micromobility product are generally covered by either UL 2849-20 or UL 2272-24; however, these UL standards reference battery requirements in UL 2271-23 in addition to other UL standards. User replaceable battery packs intended for use in a micromobility product that are sold separately from the product are within the scope of UL 2271-23.

Figures 2 and 3 show representative electrical systems for eBikes and OMPs. Electrical systems consist of a motor powered by a battery pack through the motor controller and throttle. The battery pack consists of individual lithium-ion cells. A safety circuit or BMS compares the voltage, current, and temperature readings with the cell manufacturer's specified limits, and electrically disconnects the cells if the limits are exceeded. Battery chargers are connected to a user replaceable battery pack as shown in Figure 2, and to the on-board battery for non-user replaceable battery packs as shown in Figure 3. Section II.B of this preamble discusses these electrical system components in more detail.

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B. Background on Lithium-Ion Batteries Used in Micromobility Products and the Electrical System of Micromobility Products

In this section of the preamble we provide a basic explanation of lithium-ion cells, their construction, and how they function, as well as the other components that comprise the electrical systems of micromobility products, to aid in understanding how the applicable UL voluntary standard requirements described in section IV of this preamble, and CPSC's proposed additions, address the unreasonable risks of death and injury with the associated hazards.

Lithium-Ion Cells

—A lithium-ion cell is the basic unit of a battery. Lithium-ion cells are rechargeable and include the following parts as shown in Figure 4: a positive electrode (cathode), a negative electrode (anode), a separator in between the electrodes, and an electrolyte (not pictured). The anode typically consists of a copper (Cu) sheet coated with a thin layer of negative active material, such as a graphite compound. The cathode typically consists of an aluminum (Al) sheet coated with a thin layer of positive active material, such as lithium nickel manganese cobalt oxide. The separator is a thin, porous, plastic sheet that electrically insulates the cathode from the anode; it is perforated with sub-micron sized holes to allow lithium ions to move between the anode and cathode. The electrolyte is a solvent in which the electrodes and separator are immersed. The electrolyte is the medium that allows the charged lithium ions to flow between the electrodes. Metal tabs (not shown in Figure 4) are welded to the current collectors (Al and Cu sheets) and attached to the positive and negative terminals of the battery cell to connect to an external circuit. Lithium-ion battery electrolytes are flammable, unlike water-based electrolytes used in other types of rechargeable batteries such as lead-acid or nickel-metal hydride batteries. If a lithium-ion cell overheats it can enter into a self-sustaining reaction called “thermal runaway.” The heat generated by thermal runaway ignites the flammable electrolyte, building internal pressure that can result in the violent expulsion of hot gases, burning cell materials and flames from the cell casing.

EP24JN26.015

In a final assembly of a cell, long sheets of the electrodes and separator are stacked and concentrically wound in a jellyroll fashion. For a cylindrical cell, the roll is inserted into a cylindrical steel case, the electrolyte is added, and then the case is capped off. Other form factors include prismatic cells, which are wound concentrically but are flat.

Charging and Discharging a Cell: Converting Electrical Energy to Chemical Energy

—During charging of a cell, an external voltage is applied across the cell's terminals (for a micromobility product the external voltage would be from the charger). Within the cell, lithium ions move from the active material in the cathode to the active material in the anode. This converts the electrical energy from the external power source to chemical energy that the cell stores for later use during discharge. During the charging process, cell voltage increases as the cell stored charge level increases, until the cell reaches its maximum charge voltage. The cell manufacturer specifies the maximum charge voltage, charging current, and the cell surface temperature. Continued charging beyond the maximum voltage is referred to as overcharging, which can damage the electrodes and cause overheating and failure of the cell.

This process is reversed during discharge when an external load (meaning the product the battery powers) is connected across the cell's positive and negative terminals. For a micromobility product, the external load is the electrical system—motor controller/motor

etc.

Micromobility products require a battery composed of multiple interconnected cells, as explained in section II.B.3 of this preamble describing

Lithium Battery Packs.

The stored chemical energy in each cell is converted into electrical energy as the lithium ions move from the anode to the cathode inside the battery, producing electrical current flowing out of the cell and into the load. During discharge, the cell voltage drops as the stored energy is depleted. Lithium-ion cells have a minimum voltage to which they can be discharged and below which the electrodes may become damaged. If this occurs, the cell has been overdischarged, and this damage may result in overheating and cell failure during each subsequent charge cycle.

The stored energy that is available in a lithium-ion cell as it is discharged from its maximum voltage (typically 4.2 V) to its minimum voltage (typically 2.5 V) is called the cell's electrical capacity, measured in Wh (Watt-hours). A cell charged to its full capacity is at 100% state of charge (SOC). Because cell voltage ranges from its minimum to its maximum based on the SOC, manufacturers often reference cell voltage by its nominal value (typically 3.7 volts direct current (VDC)). As a convenient reference, manufacturers specify a cell's ampacity, which is the discharge current available for 1 hour; the ampacity is specified in ampere-hours (Ah). The 1-hour discharge rate is designated as C. Cells are typically capable of producing a much higher current than the C rate but for less time. Typically, rated discharge current is up to ten times C or 10C. Charging current is typically between 0.5C for a slow charge and up to three times C (3C) for a fast charge.

Another important specification for safe operation is the surface temperature of the cell during charge, discharge, and storage. The cell manufacturer specifies the temperature ranges a cell may be safely subjected to for specific modes such as charge, discharge, and storage. The typical safe range for cell surface temperatures during charging is between 0 °C and 45 °C. The typical safe

range for cell surface temperatures during discharge is between 0 °C and 60 °C. While a cell is discharging, internal heating is produced that is proportional to the current. For a micromobility product, nearly all the battery power is for the motors. When the motor works harder, such as to go faster or ride up an incline, the current increases, and the cells produce more heat. To prevent damage to a battery cell during charge and discharge, a battery-powered system must maintain the battery cells within the described specifications, referred to collectively as the safe area of operation. Battery cells that are overcharged, overdischarged, or that exceed the allowable temperature can suffer catastrophic failure. The most severe type of failure is thermal runaway, which is rapid, extreme overheating of the cell leading to venting of hot, hazardous gases from the cell, which can lead to fire escaping from the product, as detailed in section III of this preamble.

A variety of electrode compounds provide various performance specifications for battery pack designers to use. A cell manufacturer publishes the specifications for voltage, current, cell surface temperature, and capacity so that battery designers can select the cell that meets or exceeds the performance requirements in the end-use application.

Lithium-Ion Battery Packs

—Micromobility products are typically sold with a battery pack that is rated for the intended use of the product. The battery pack is an assemblage of individual lithium-ion cells connected electrically in series and parallel to achieve the voltage and current ratings for the micromobility product to operate for the desired range, runtime, and top speed. A battery pack may be fixed-in-place (non-replaceable), or it may be replaceable by the user to facilitate charging the battery separately from the product or to allow battery replacement. Removable batteries allow users to ride the product with minimal downtime, because users can charge an extra battery while using the product. Micromobility product manufacturers may sell battery packs specifically for their products, but battery packs may also be sold by third parties.

Micromobility product batteries typically use cylindrical lithium-ion cells, often size 18650 or 21700. Figure 5 shows examples of each of these cells. Size 18650 cells are nominally 18 mm in diameter and 65 mm tall; size 21700 cells are nominally 21 mm in diameter and 70 mm tall. Micromobility product battery packs use multiple battery cells connected in series and parallel so that the battery can provide sufficient power and capacity to operate the micromobility product within the manufacturer's desired range or operating time.

EP24JN26.016

Micromobility product multi-cell battery arrangements are designated by the number of cells connected electrically in a series string, and the number of series strings that are connected in parallel. For example, a 20-cell, 10S2P battery has ten cells connected in each series (

i.e.,

“10S”) and two parallel series (

i.e.,

“2P”). Thus, this pack configuration consists of 20 cells. Figures 6 and 7 provide examples of battery packs and their designations.

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Battery Management Systems

—To maintain the individual cells of a battery pack within their specifications for voltage, current, and temperature during charge and discharge, a robustly designed micromobility product electrical system uses a BMS, an example of which is shown in Figure 8. When the BMS detects an out-of-specification cell condition, it uses electronic switches or relays to disconnect the battery pack from the external circuit to stop the flow of current and to prevent damage to battery cells, which could lead to thermal runaway. For example, during charging and discharging, the BMS measures and compares the voltage, current, and temperature readings to the cell manufacturer's specified limits. A BMS measures cell surface temperatures using thermocouples or thermistors, which are sensors attached to the outside of the battery cells inside a battery pack. The BMS controls the charging rate and charge level while monitoring the cell temperature so that the cells stay within their safe area of operation. The BMS stops charging when cells reach their full capacity so that they do not become overcharged. Similarly, the BMS stops discharging when cells reach their minimum voltage so as not to allow overdischarge. Accordingly, the BMS plays a critical role in the safe operation of a micromobility product, particularly when the user is charging or riding the product.

A BMS, however, cannot stop thermal runaway events caused by manufacturing defects in the battery cell itself, such as contaminants, electrode or separator layer misalignment, damaged separator, or folded or torn electrodes.

User Replaceable Battery Packs

—Some of CPSC's incident reports involve user replaceable batteries that were poorly constructed with substandard cells, BMS, or other components. User replaceable battery packs may be available from the micromobility product OEM or from a non-OEM

supplier. User replaceable battery packs (batteries) become part of the product's electrical system. The primary risks associated with user replaceable battery packs, similar to integral batteries, are shock and fire. The cells within battery packs must be maintained within their safe area of operation during both charging and discharging, requiring adequately rated cells and BMS protection. Also, because the battery output terminals for electrically connecting the battery to the micromobility product may be exposed, they need to be properly guarded to protect against possible shorting during connection and disconnection of the battery pack. If the battery pack voltage is higher than 60 V DC, the battery output terminals must also be inaccessible to users to prevent a risk of shock. Further, battery packs without a means to prevent users from accessing the battery, meaning those that are not tamper resistant, present a risk of shock and fire by allowing consumer access to internal parts of the battery pack to, for example, attempt to replace battery cells. CPSC is also aware of consumers trying to build or modify lithium-ion battery packs for micromobility products, without necessarily having technical expertise or knowledge of the risks. These so-called “homemade” or modified batteries may pose a higher risk of a thermal runaway, and potential smoke inhalation and fire, as set forth in section III of this preamble.

OEM and Aftermarket Battery Chargers

—CPSC is aware of incidents involving chargers provided either with the micromobility product (OEM charger) or obtained afterwards (aftermarket charger). Several risks to the consumer are associated with OEM and aftermarket battery chargers. Battery chargers are powered from 120 VAC power so that basic safety requirements such as proper grounding and power cords ratings are beneficial to protect users against shock and fire. Chargers may also overheat if adequate internal circuit protection is not provided. However, the primary concern with aftermarket chargers is compatibility with the micromobility product charging circuit and battery. It is critical that the charger output voltage and current match the rating of the micromobility product battery to prevent damage to the internal charging circuits or the battery, which can pose a risk of fire. Also, the voltage polarity of the charger connector must match the polarity of the micromobility product charging connector to mitigate the risk of damaging the cells and posing a risk of fire.

C. Market Description

The following discussion provides information about the economic markets in which micromobility products are sold. In 2021, CPSC contracted Euromonitor to conduct an industry-wide market study on micromobility products. The Euromonitor report, completed in February 2022, is titled

Micro-Mobility Product Market Research.

The information provided in this section, unless otherwise stated, is derived from the Euromonitor report. This market analysis is broken into three product categories: eBikes, eScooters, and OMPs, which for this analysis includes eSBscooters, eSkateboards, eUnicycles, and hybrids of these products).

This report can be obtained by submitting a request at

https://forms.office.com/g/2ubiRFZxfw.

The information presented summarizes the market analysis in Tab A of Staff's NPR Briefing Memorandum: Safety Standard for Lithium-Ion Batteries in Micromobility Products Preliminary Regulatory Analysis, available at

https://www.cpsc.gov/s3fs-public/LithiumIonBatteriesPreliminaryRegulatoryAnalysis.pdf.

eBikes

—CPSC staff identified 179 firms that manufacture or supply eBikes to the U.S. Most of these firms import products manufactured in China. Staff have identified just five domestic eBike manufacturers. Overseas companies produce many of the components used by these domestic manufacturers; in particular, nearly all eBike batteries are manufactured overseas. eBikes are typically sold through physical retail outlets; recently, however, an increasing number of eBikes are being sold through online retailers. Staff expect this trend to continue in the short run but do not expect this online sales trend to exceed 30 percent of total sales because eBike firms maintain a physical dealer network.

Currently, the domestic eBike market is growing quickly, with a 31 percent compounding annual growth rate (CAGR) in units sold from 2018 to 2024. Increased recreational use of eBikes and investments made by ride sharing firms in major cities have contributed to the market's quick growth. Despite investments by ride sharing firms having slowed considerably recently, the overall eBike market has continued to grow. High growth rates for this market are likely to continue in the short run.

eScooters

—Staff identified 81 firms supplying 704 eScooter models/variants to the U.S. market. Nearly all eScooters are imported from China or Taiwan. Of the 81 firms, staff identified seven U.S. domestic eScooter manufacturers and overseas companies produce many of the components used by these domestic manufacturers, including nearly all eScooter battery packs. Private eScooter sales account for approximately 65 percent of the total market with a majority sold via on-line retail channels. A few firms have a limited brick-and-mortar presence. From 2018 to 2021, eScooter sales volume increased at a 9.8 percent CAGR. Over the same period, eScooter gross revenue increased at a 27.7 percent CAGR. The higher growth rate in revenues compared to sales is due to a shift towards higher quality and more durable products. Beyond 2021, sales growth is expected to slow down to 10.64 CAGR and staff expect growth to further decline as the market continues to saturate.

OMPs

—Staff identified 67 firms that manufacture or supply OMPs to the U.S. market. Nearly all these firms import their products from China. Staff identified 12 domestic OMP manufacturers that assemble OMPs from components largely produced overseas. Most lithium-ion batteries for OMPs are produced in China. Roughly 80 percent of OMPs are sold via online retail channels rather than through brick-and-mortar retailers.

Revenue for eSBscooters with a handlebar (a.k.a. segways) increased at a 4.3 percent CAGR from 2018 to 2021, while units sold increased to 1.7 percent CAGR during the same period. One reason for the increase in retail value is the increase in cost for batteries and electric motors stemming from the COVID-19 pandemic. eSBscooters without a handlebar, such as hoverboards, entered the market in 2015. Sales of these eSBscooter increased at 2.5 percent CAGR from 2018 to 2021. eSBscooter prices have increased marginally because of higher global demand for batteries, but they have generally been constrained by the economies of scale from producing over a million units per year.

eSkateboards and eUnicycles have the highest growth from 2018 to 2021. Sales grew from 2018 to 2021, at a CAGR of 5.3 percent. Retail value grew at a 13 percent CAGR during that same period. Overall, OMPs are forecasted to increase at a 15.6 percent CAGR from 2021 to 2024, reaching a market value of $213.2 million.

D. Overview of Voluntary Standards and CPSC's Participation in Standards Development

UL 2272 Background

—UL 2272 was first published in November 2016 as a joint Canada-United States National Standard to address the electrical safety of “Electrical Systems for Personal e-Mobility Devices.” UL 2272-24 defines a “personal e-mobility device” as a

single-rider, rechargeable electric device which may or may not be self-balancing, excluding devices for medical purposes.

This voluntary standard was created in response to fire incidents with eSBscooters that occurred at the end of 2015 when these products were widely introduced in the market without a standard to ensure safe operation of the battery. The first edition was revised on February 25, 2019. After the 2019 revisions were published, OMP fire incidents continued. To address these incidents, staff wrote a letter to UL Standards and Engagement (ULSE) Technical Commission (TC) on January 14, 2024, indicating a need to create a working group to address OMP incidents.

As a result of this letter, the TC for UL 2272 initiated work and, on April 19, 2024, ULSE published the second edition of UL 2272. However, as discussed below, incidents associated with OMPs continue and staff's current assessment of this standard is that it is inadequate to fully address the associated hazards for consumers of OMPs using lithium-ion battery packs.

UL 2272 refers to in-scope products as “personal eMobility devices,” but this NPR generally refers to such products as “other micromobility products” or OMPs.

The letter is posted on CPSC's website, located at the following link:

https://cpsc.gov/s3fs-public/e-MobilityTG-ResponseToWGActivity-ULSE-0.pdf?VersionId=hpYjELySGyjiOrKFUaJCpgJxqCoufjAI.

UL 2271 Background—

UL 2271 was first published in December 2013 as a joint Canada-United States bi-national standard to address electrical energy storage assemblies such as battery packs for use in light electric-powered vehicles (LEVs).

The second edition was published in 2018. The third and latest version was published in 2023. Although staff assess that the revisions increased safety relative to the previous edition, nevertheless the standard does not fully address the associated electrical hazards for consumers of eBikes and OMPs using these battery packs, as reflected in the discussion of incidents in section III of this preamble.

UL 2271-13 includes the following as LEVs: electric bicycles; electric scooters and motorcycles; electric wheelchairs; golf carts; ATVs; non-ride-on industrial material handling equipment; ride-on floor care machines and lawnmowers; and personal mobility devices.

UL 2849 Background—

In January 2020 as a joint Canada-United States National Standard to address the electrical system safety of eBikes powered by a lithium-based, rechargeable battery. Staff attended a TC meeting for UL 2849 on December 6, 2021, to review numerous proposals for additional eBike requirements. To date, these proposals have not been balloted. Moreover, as discussed in section III of this preamble, eBike fire incidents continue.

III. Hazards Associated With Lithium-Ion Batteries Used in Micromobility Products

This section discusses the unreasonable risk of death and injury associated with lithium-ion batteries used in micromobility products, provides information on the deaths and injuries associated with micromobility products within the scope of the rule, and describes the associated hazard patterns.

See also,

Consumer Product Safety Commission (2023) Micromobility products-related deaths, injuries, and hazard patterns: 2017-2022, available at:

https://www.cpsc.gov/s3fs-public/Micromobility-Products-Related-Deaths-Injuries-and-Hazard-Patterns-2017-2022.pdf?VersionId=BekCvIY03IvMU9nHr2ErziUNXNkPAghJ.

A. Unreasonable Risk of Death or Injury Associated With Lithium-Ion Batteries Used in Micromobility Products

As seen in CPSC's incident data described in section III.B of this preamble, the primary risks of injury are associated with thermal runaway of micromobility electrical systems that use lithium-ion batteries, which can lead to fires, explosions, gas releases, burns, overheating, and smoke inhalation. Consumers are exposed to these risks during charge and discharge of lithium-ion batteries used in micromobility products. Thermal runaway in a lithium-ion battery pack(s) creates a risk of injury that can be mitigated by using high quality cells and monitoring and protection circuitry provided by the electrical system, including such subsystems as the BMS. As described in section II.B.4 of this preamble, a properly designed and well-functioning BMS ensures that if a lithium-ion battery or battery pack operates outside of the safe operating region it will be disconnected from the external circuit, which turns off the battery pack to prevent damage to battery cells within the battery pack, and ultimately may prevent a thermal runaway.

Lithium-ion cells operating outside of their safe operating region may suffer internal damage, which may lead to an internal short circuit that generates extreme heat. Depending on the level of charge, the rapidly released energy may heat the cell much faster than the cell can dissipate the heat. Furthermore, unlike water-based electrolytes used in other types of rechargeable batteries, lithium-ion battery electrolytes are flammable. This may result in a self-heating, exothermic chemical reaction called thermal runaway. A cell in thermal runaway burns and vaporizes the flammable electrolyte building intense internal pressure that may rupture the cell casing explosively, ejecting hot gases, flames and molten materials. In a multicell battery pack, the heat produced by the failure of one cell may propagate to other cells in the pack, expanding the release of extreme heat and fire due to thermal runaway induced in other cells. Tests performed by Naval Surface Warfare Center, Carderock Division demonstrated that cell burn temperatures during thermal runaway can exceed 1000 °C (1832 °F).

Waller, Ko, Hays, Jiang (2020) Evaluation of Cell-to-Cell Propagation in Lithium-ion Batteries Containing 18650 Sized Cells, NSWCCD-63-TR-2020/01,

https://www.cpsc.gov/content/Consumer-Product-Safety-Commission-CPSC-Staff%E2%80%99s-Statement-on-Naval-Surface-Warfare-Center-Carderock-Division%E2%80%99s-NSWCCD-Report-on-%E2%80%9CEvaluation-of-Cell-to-Cell-Propagation-in-Lithium-Ion-Batteries-Containing-18650-Sized-Cells%E2%80%9D.

Once ignited, flaming contents and gases build internal pressure and can be explosively ejected from the cell enclosure. The flaming materials may ignite nearby combustibles. Micromobility products are often left to charge inside of a garage, house, or multifamily dwelling. Fires in these locations can spread to surrounding household goods and combustible materials stored in those locations, such as gas or kerosene in a garage, and carpets, furniture, drapes, decorative items, and other electronic equipment in the house. Fires can also ignite the housing structure itself.

Smoke produced by combustion is a colloid consisting of airborne solids, liquid particles, and gases (

e.g.,

, CO) mixed with air.

During combustion inside of a battery, a carbon-based fuel burns in the presence of oxygen. Harmful gases and fire may result in injuries and deaths to anyone inside the house or building. According to CPSC's reports of in-depth investigation (IDI) and the National Electronic Injury Surveillance System (NEISS) submitted from 2019 to 2023, the main causes of human death and injuries associated with micromobility product fires are smoke inhalation and burn injuries.

Gill P. and Martin R.V. (2015) Smoke inhalation injury,

BJA Education,

15(3): 143.

B. Incident Data Overview

CPSC staff searched CPSC-maintained databases to identify deaths, injuries, and non-injury incidents associated with lithium-ion batteries used in micromobility products, including the

Consumer Product Safety Risk Management System (CPSRMS)

17 18

and the National Electronic Injury Surveillance System (NEISS).

For this NPR, CPSC identified 227 unique incidents related to associated hazards with micromobility products' lithium-ion batteries from January 1, 2019, through December 31, 2023, which were documented in CPSC databases as of November 1, 2024.

CPSRMS includes data primarily from three groups of sources: incident reports, death certificates; and in-depth follow-up investigation reports. A large portion of CPSRMS consists of incident reports from consumer complaints; media reports; medical examiner or coroner reports; retailer or manufacturer reports (incident reports received from a retailer or manufacturer involving a product they sell or make); safety advocacy groups, law firms, and federal, state, or local authorities, among others. It also contains death certificates that CPSC purchases from all 50 states, based on selected external cause of death codes (ICD-10). The third major component of CPSRMS is the collection of in-depth, follow-up investigation reports. Based on the incident reports, death certificates, or NEISS injury reports, CPSC Field staff conduct in-depth investigations (on-site, telephone, or online) of incidents, deaths, and injuries, which are then stored in CPSRMS.

CPSC staff searched all data coded under product codes 3215/5045 (eBikes), 5022/5024 (eScooters), 5025 (eSBscooters, eSkateboards, eUnicycles), 1283 (Unicycles), and 5042 (Scooters, eSBscooter, Skateboards). In addition, staff extracted data coded under 884 (Batteries), 883 (Battery Chargers/adapters), and 9901 (Unclerically coded retailer products). Staff further screened data searched from this wide range of products using keywords to identify potentially in-scope micromobility products or lithium-ion batteries which may have been used in micromobility products at the time of the incident. Staff extracted data on November 1, 2024, and reporting for 2022-2023 is ongoing. Counts may change in future reports.

NEISS is the source of the injury estimates; it is a statistically valid injury surveillance system. NEISS injury data are gathered from participating hospitals with 24-hour emergency departments and at least 6 beds, selected as a probability sample of all U.S. hospitals. The surveillance data gathered from the sample hospitals enable the staff to make timely national estimates of the number of injuries associated with specific consumer products.

Specifically, CPSC conducted 212 In-Depth Investigations (IDIs), identified 12 additional NEISS cases,

and obtained three news reports as presented in table 1.1. Of the resulting total of 227 incidents associated with micromobility product electrical systems, 90 incidents are associated with fatalities (39) and injuries (181), while 39 incidents involved multiple victims with fatalities and injuries. CPSC is also aware of 137 non-injury incidents within the same timeframe.

NEISS estimates are not given if they do not meet the NEISS reportability criteria: that the estimated number of injuries be 1,200 or higher, the sample size be 20 or larger, and the coefficient of variation does not exceed 0.33.

EP24JN26.020

Table 1.2 shows the number of incidents, fatalities, injuries, and non-injury incidents associated with micromobility product electrical system fire, explosion, overheating incidents by year from 2019 through 2023. Table 1.2 summarizes information on deaths, injuries, and non-injury incidents for each product category.

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Using these data staff identified hazards associated with lithium-ion batteries used in micromobility product electrical systems, including fires, explosions, and other hazards such as gas releases, burns, overheating, and smoke inhalation. Table 1.3 shows the overall incident counts, fatalities, injuries, and non-injury incident counts. Out of the 227 incidents, fire incidents accounted for 195 incidents (86 percent), 39 fatalities (100 percent), 174 of the 181 injuries (96 percent), and 112 of the 137 non-injury incidents (82 percent).

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Table 1.4 summarizes the hazard pattern counts of different product types for each incident associated with a lithium-ion battery used in a micromobility product electrical system. Out of the 227 total incidents, 120 incidents (53 percent) occurred while the product was plugged in charging, including 18 fatalities (46 percent), 102 injuries (56 percent), and 73 non-injury incidents (53 percent). Another 23 incidents were reported while the product was being stored or resting in open space and unexpectedly caught fire, causing a total of four deaths and 36 incidents of non-fatal injury. Thirty incidents with no deaths, which injured eight people, were mainly associated with products while in use, shortly after use, or after charging. User removing/replacing battery packs or using an aftermarket battery/charger accounted for 25 incidents, two deaths, and 12 people injured. Three incidents associated with the product contacting water were reported, including one death and no non-fatal injuries. Four incidents associated with homemade battery packs were reported with three fatalities and two injuries while victims were manufacturing, repairing, or charging batteries. The remaining 22 incidents did not provide specific hazard descriptions but accounted for 11 deaths and 21 injuries.

BILLING CODE 6355-01-P

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Among the 39 fatalities associated with micromobility lithium-ion battery fires, each sex had 19 fatalities, as well as one fatality for unknown sex. Of the

159 injured victims with known age, 85 were males (53 percent) and 74 females (47 percent). Of the 129 non-injury incidents with known sex, 95 were males (74 percent) and 34 females (26 percent). Table 1.5 presents the distribution of victims by product type and sex.

EP24JN26.024

Table 1.6 presents the incident data by product type and victim age group. Two hundred ninety-seven (about 83 percent) out of 357 total victims had age information provided. Of the 37 fatalities with age information, four (about 11 percent) were under 5 years old and nine (about 24 percent) were 65 and older. These fatality rates for both the `under 5 years old' and `65 and older' groups were disproportionately higher compared to their corresponding proportions in the general U.S. population. Among the 112 non-injury victims with age information, 50 (about 45 percent) were in the 25-44 age group which is also disproportionately higher compared to the general population.

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Incidents with Multiple Victims

—Thirty-nine incidents involved multiple injured or deceased victims, including eight incidents involving fire that resulted in two or more deaths in each incident (collectively accounting for 24 deaths and 19 injuries). An additional 31 incidents involving a fire resulted in multiple victims with one or no deaths in each incident (collectively accounting for eight deaths and 118 injuries). Table 2.1 summarizes information on incidents, deaths, and injuries in multiple victim incidents involving lithium-ion batteries used in micromobility products and the associated hazards, including fires.

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Of the 169 victims involved in multi-victim incidents, 32 were killed and an additional 137 were injured. Of the 32 fatalities, 15 were males, 16 were females, and one unknown sex. One hundred sixteen out of the 137 injury incidents identified the sex of the victim, and these were equally divided between males and females. Table 2.2 presents the distribution of sex by product type.

EP24JN26.027

Table 2.3 shows the hazard pattern data by product type. Twenty-one out of the 39 incidents involving multiple-victim incidents (about 54 percent) occurred while the product was plugged in charging, including 15 out of 32 fatalities (about 47 percent) and 79 out of 137 injuries (about 58 percent). Seven multi-victim incidents were reported while the products were being stored or resting in open space and unexpectedly catching fire, causing four deaths and 33 injuries. Two incidents with five injuries were associated with products during use, shortly after use, or after unplugging a charger from the product. Users removing or replacing the battery and using a user replaceable battery or aftermarket charger were associated with four incidents, two deaths, and nine injuries. An incident was reported in which the victim was manufacturing, repairing, and charging homemade lithium-ion batteries, resulting in one death and two injuries. The remaining four multiple-victim incidents did not provide specific hazard description but accounted for 10 deaths and nine injuries.

BILLING CODE 6355-01-P

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Incidents involving Single Victim

—Of the 188 incidents with single victims, 51 incidents resulted in seven deaths and 44 injuries, as set forth in table 3.1.

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Of the seven fatalities, four were males and three were females. Twenty-seven out of 43 single-injury incidents with known sex (about 63 percent) were males versus 16 females (about 37 percent). Table 3.2 presents the distribution of sex by product type.

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Table 3.3 shows the distribution of hazard pattern data by product type. Out of the 188 incidents, 99 incidents (about 53 percent) occurred while the products were plugged in charging, leading to three out of seven fatalities (about 43 percent), 23 of 44 injuries (about 52 percent), and 73 out of 137 non-injury incidents (about 53 percent). Another 16 incidents were reported while the products were being stored or resting in an open space and unexpectedly catching fire, causing three injuries. Twenty-eight incidents with three injuries were mainly associated with products while in use, shortly after use, or soon after charging. `User removing/replacing battery' and `Aftermarket battery/charger' accounted for 21 incidents with three injuries. Three incidents involved products in contact with water, causing one death. Three incidents, resulting in two deaths, were associated with the victims manufacturing, repairing, and charging lithium-ion batteries. The remaining 18 incidents did not provide specific hazard description but accounted for one death and 12 injuries.

BILLING CODE 6355-01-P

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C. Hazard Patterns From the Incident Data

As summarized in table 1.4 in section III.B of this preamble, CPSC identified the following nine hazard patterns in the incident data associated with lithium-ion batteries used in micromobility products, or within an electrical system of a micromobility product.

Charging

—CPSC is aware of 120 incidents associated with thermal runaway during normal charging of micromobility products, resulting in 18 deaths and 102 injuries. For example, in IDI 211005CAA1026 the consumer fully charged an eBike battery after purchase and approximately 3-5 times each week thereafter. A few months after purchase, the consumer reportedly used the adapter that came with the eBike to charge the battery. The consumer arrived home in the evening to discover that the fire department had extinguished a fire in his living room, where the eBike was located. Fire officials determined that the rechargeable battery on the eBike had exploded and started a fire. The consumer found the remains of the battery on the floor next to the bike, surmising that it had blown off when the battery exploded.

In another example, IDI 220119CCC1747, an eSBscooter reportedly caught fire while on an extended charge. The eSBscooter had been purchased new by the consumer about 19 months earlier from an online retailer and used without incident until the fire. The consumer used the product and then plugged it in to charge in the garage. Approximately one week later, the consumer heard a smoke alarm and observed flames coming from the garage. Firefighters determined the fire originated from the eSBscooter, which had overheated from being charged and began to melt, catching a nearby mattress on fire.

Spontaneous (Stored or Resting in Open Space)

—CPSC is aware of 23 spontaneous incidents while the micromobility product was being stored or resting in an open space. These incidents resulted in four deaths and 36 injuries. For example, in IDI 231221CCC1586, a fire originated in an apartment with two skateboards that were left by the front entrance door. Neither product was being charged at the time of the incident or was recently used.

Discharge (During or Shortly After Riding)

—CPSC is aware of 18 incidents while the micromobility product was in use, resulting in four injuries. For example, in IDI 230713CFE0001, a 14-year-old male was riding an approximately year-and-a half old stand-up, rechargeable eScooter when the battery caught fire and started smoking and burst into flames, shooting out individual battery cells up to four feet away from the eScooter. The teen reported that he always used the original factory charger to charge the eScooter.

Another example of a discharging incident is documented in IDI 231130CCC1429. A 67-year-old female started her eBike and reported that the battery suddenly exploded with flames bursting out of the bike. The eBike was purchased new a month or so before the incident along with a second identical unit. The consumer reported assembling the product per the instructions, but did not assemble anything in relation to the battery.

After Charging or Unplugging

—CPSC is aware of 12 incidents after the micromobility product was charged and unplugged, resulting in four injuries. For example, in IDI 220525CBB3911, the consumer went to unplug the charger from an eScooter with an OEM replacement battery after about a month on the charger, and the product sparked, caught fire, and emitted smoke. The area above the charge port was scorched and the eScooter was no longer operable.

In IDI 210824CFE0001, the consumer was awakened by a loud explosion and saw dark black smoke and fire emitting from the area where his eScooter was located after being charged overnight. The apartment sustained fire, smoke, soot, and water damage, leaving it uninhabitable.

Battery Removal or Replacement

—CPSC is aware of eight incidents after the user removed or replaced the

battery, resulting in four injuries. In several of these incidents, consumers were attempting to install a replacement battery sent by the manufacturer (IDI 220908CCC1337, 220908CCC1339, 220908CCC1340).

Aftermarket Battery or Charger

—CPSC is aware of 17 incidents involving aftermarket batteries or chargers, resulting in two deaths and eight injuries. For example, in IDI 220805CFE0001, lithium-ion batteries self-ignited during the charging process in an apartment, resulting in a fire and the deaths of a 5-year-old female and a 36-year-old female. The batteries were being charged using an aftermarket charger plugged into an extension cord. During a federal line-of-duty death investigation of a career firefighter, investigators determined that the fire origin was from using a lithium-ion battery-powered device and an aftermarket charger together, causing the batteries to overheat, go into thermal runaway, and start a fire. CPSC has warned consumers against using aftermarket universal chargers that are not compatible with their intended micromobility products.

https://www.cpsc.gov/Warnings/2024/CPSC-Warns-Consumers-to-Immediately-Stop-Using-SafPow-and-AMPOWSURE-Battery-Chargers-Sold-on-Amazon-com-Due-to-Fire-and-Burn-Hazards-Risk-of-Serious-Injury-and-Death.

Contact with Water

—CPSC is aware of three incidents involving micromobility products having been in previous contact with water, resulting in one death. In the fatal incident (X2390880A), a fire started on a boat. According to the police, the cause of the fire was an eBike battery that had fallen into the water the day before the incident.

Homemade Battery

—CPSC is aware of four incidents involving homemade batteries, resulting in three deaths and two injuries. In IDI 200909CFE0001, the consumer used parts of a camper battery to make a homemade eBike battery. In IDI 230213CAA1777, investigators believe the consumer purchased a conversion kit that changes a standard bicycle into an eBike. Investigators hypothesize the battery was “homemade” because they found remnants of cardboard and duct tape.

Unspecified

—CPSC is aware of 22 incidents involving micromobility products with no identified hazard patterns, resulting in 11 deaths and 21 injuries.

10.

Use and Hazard Patterns Associated with Micromobility Products

—CPSC staff categorized the use patterns and associated hazard patterns prior to the fires identified from the incident data, including Unsafe Battery, Unsafe Charging, Unsafe Discharging, Incompatible Components, Tampering and Unknown. Table 4 provides a summary of the use patterns observed in the incident data and the associated hazard patterns.

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D. Mechanisms of Injury

Smoke Inhalation

—In general, smoke inhalation is the most common cause of death in fire incidents.

The reported casualties (fatality and serious injury) were primarily caused by fires of house structures and surrounding combustible materials (

e.g.,

furniture, bedding items) after an initiation of fire from a lithium-ion battery for micromobility products. Smoke inhalation produces respiratory complications and injuries, including thermal injury to the upper airway from heated gases, irritation to the airways, asphyxiation or oxygen depletion by carbon monoxide (CO) and hydrogen cyanide (HCN),

hydrogen chloride (HCl) gas inhalation-associated airway blockage, and atmospheric oxygen depletion by burning.

Gill P. and Martin R.V. (2015) Smoke inhalation injury,

BJA Education,

15(3): 143.

Lafferty KA, Bonhomme K, Martinez CV et al. Smoke inhalation Injury (2021). Available from

http://emedicine.medscape.com/article/771194-overview

(accessed 04 June 2024).

Alarie Y. (2002) Toxicity of fire smoke,

Crit. Rev. Toxicol.

32(4): 259.

Patients who suffer burn injury also are likely to be exposed to smoke and hazardous gases. Asphyxiation, or insufficient oxygen levels, is the primary cause of unconsciousness or death from such exposure. CO is the main asphyxiant gas in fires, and CO poisoning is the primary cause for half of all deaths during fire.

CO binds with hemoglobin in red blood cells, which is responsible for carrying oxygen to all parts of the body. CO has a much higher binding affinity to hemoglobin than oxygen. This competitive binding of CO over oxygen with hemoglobin reduces oxygen transportation to the cells, resulting in hypoxic (or insufficient oxygen associated) injury of all tissues of exposed subjects. The brain and the heart are particularly vulnerable to hypoxia, and prolonged exposures are increasingly harmful.

Roeland Bisschop, Per Blomqvist, Alastair Temple, Johan Anderson, RISE (2020) Toxic Gases from Fire in Electric Vehicles, Ola Willstrand, RISE Research Institutes of Sweden, RISE Report 2020:90.

HCN is also generated in fires, particularly those involving synthetic materials (

e.g.,

furnishings, plastics, vinyl). HCN binds the enzyme cytochrome C oxidase and blocks the mitochondrial transport chain that results in the depletion of adenosine triphosphate (ATP), the source of energy at the cellular level. The depletion of ATP is followed by the impairment of vital functions of cells that ultimately disable organs, such as the lung, the heart, and the central nervous system. The presence of HCN also increases the adverse effects of CO when it is also present.

Gill P. and Martin R.V. (2015).

HCl is a corrosive irritant that is generated in fires, particularly those involving materials containing chlorine (

e.g.,

polyvinyl chloride). The presence of gaseous HCl exacerbates the irritating and choking effects of the smoke. HCl in fire smoke when inhaled causes laryngeal and bronchial spasm and generates massive pulmonary edema, leading to suffocation.

Alarie Y. (2002).

Fires consume oxygen and therefore can significantly reduce the levels of oxygen in the air indoors. Reduced oxygen levels can result in incapacitation or loss of consciousness of people near fires and contribute to deaths and serious injuries.

Furthermore, the heat of active fires may cause heat shock injury and death in nearby people, especially if victims are incapacitated.

Alarie Y. (2002).

Exposure to Chemicals

—In addition to the generation of asphyxiant and corrosive gases and heat, lithium-ion battery fires and involvement of surrounding household goods and combustible materials may produce other chemical substances that could be inhaled or absorbed through the skin. Fire-associated chemicals (and their associated potential adverse effects) may include:

• Metals, such as aluminum (Al), lithium (Li), cobalt (Co), nickel (Ni), and manganese (Mn): respiratory tract irritation and asthma;

29 30

RISE (2023) Investigation of extinguishing water and combustion gases from vehicle fires, Hynynen J., Willstrand O., Blomqvist P., Quant M. RISE Research Institutes of Sweden, RISE Report 2023:22.

Nemery B. (2022) Chapter 19—Metals and the Respiratory Tract, Pages 421-443, Handbook on the Toxicology of Metals (Fifth Ed.), Editors: Gunnar F. Nordberg and Max Costa, Academic Press

• Other irritant gases, such as hydrogen fluoride (HF), sulfur dioxide (SO

), and nitrogen dioxide (NO

): respiratory tract irritation and corrosion of upper respiratory tract tissues;

31 32 33

RISE (2020).

National Research Council (US) Committee on emergency and continuous Exposure Guidance Levels for Selected Submarine Contaminants (2009) Emergency and continuous exposure guidance levels for selected submarine contaminants: Volume 3, National Academies press, Washington, DC

https://www.ncbi.nlm.nih.gov/books/NBK219903/.

Gaskin S., Heath L., Pisaniello D., Logan M., and Baxter C. (2019) Skin permeation of oxides of nitrogen and sulfur from short-term exposure scenarios relevant to hazardous material incidents. Sci. Total Environ. 665, 937.

• Per- and polyfluoroalkyl substances (PFAS): changes in enzymes and adverse physiological responses, altered immune and thyroid function, lipid and insulin dysregulation, adverse reproductive and developmental outcomes;

34 35

Quant M., Willstrand O., Mallin T, and Hynynen J. (2023) Ecotoxicity Evaluation of Fire-Extinguishing Water from Large-Scale Battery and Battery Electric Vehicle Fire Tests. Environ. Sci. Technol. 57, 4821.

Fenton SE, Ducatman A., Boobis A., DeWitt J.C., Lau C., Ng C., Smith J.S., and Roberts S.M. (2021) Per- and polyfluoroalkyl substance toxicity and human health review: Current state of knowledge and strategies for informing future research. Environ. Toxicol. Chem. 40, 606.

• Volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs), including benzene and benzo(a)pyrene:

29 31

respiratory tract irritation and inflammation,

36 37

and;

Agency for Toxic Substances and Disease Registry (ATSDR) (2007) Toxicological Profile for Benzene.

https://www.ncbi.nlm.nih.gov/books/NBK591289/.

Bukowska B., Mokra K., and Michalowicz J. (2022) Benzo[a]pyrene-Environmental occurrence, human exposure, and mechanisms of toxicity. Int. J. mol. Sci. 23, 6348.

• Particulates: respiratory irritation, increased severity of asthma and chronic obstructive pulmonary disease (COPD) in patients with the symptoms.

38 39 40 41

Premnath V., Wang Y., Wright N., Khalek I., and Uribe S. (2022) Detailed characterization of particle emissions from battery fires. Aerosol Sci. Technol. 56, 337.

Quant M. et al. (2023).

RISE (2020).

ATSDR (2024) Guidance for inhalation exposures to particulate matter.

The hazards associated with exposure to chemicals released or generated by lithium-ion battery fires and involvement of surrounding combustible materials depend on the specific substances emitted during the event, levels of toxicity of the substances, and levels of exposure, as well as vulnerability of exposed subjects. Exposure to chemicals from a lithium-ion battery fire likely will be limited if individuals notice the fire at an early stage and are able to escape. However, in the case that a failing battery or fire is not immediately recognized, or when individuals cannot escape, prolonged exposure to the emitted chemicals may be associated with more severe injury and death from exposure to asphyxiant gases, heat, or the fire itself.

Electric Shock

—An electric shock occurs when an electric current passes through a human body. The electric shock can cause death and injuries to humans. Three basic factors that determine effects of electric shock are current levels, exposure duration of contact, and electrical frequency.

Although current is the primary determinant of subsequent health adverse effects of electric shock, voltage also influences the outcome of an electric shock.

Electric current, measured in amperes (A), is defined as a flow of charged electrons or ions. There are two types of electric current, alternating current (AC) and direct current (DC). The current associated with household electrical outlets is AC that continuously changes direction from a positive to a negative value. In contrast, DC current, such as from batteries, is a unidirectional current. Voltage is defined as electric potential between two points, functioning as a force moving the current from one point to another point.

BrightHub Engineering, AC and DC Electric Shock Effects Compared, available at:

https://www.brighthubengineering.com/power-plants/89792-ac-and-dc-shock-comparison/

(last accessed 09/10/2024).

Fish R.M. and Geddes L.A. (2009) Conduction of electrical current to and through the human body: A review,

Eplasty,

9: e44.

Exposure to electric current causes various effects on a human body, depending on the level, including stimulation of muscles and nerves, and respiratory or cardiac arrest.

The maximum current under which an average adult can voluntarily release an electrified object is called the “let go” current. The let-go currents of AC and DC are 16 mA and 75 mA for most adults, respectively.

45 46

For electric currents above the let-go levels, exposed humans may not be able to drop an energized object because of muscle contraction, unless the current flow stops.

Fish R.M. and Geddes L.A. (2009).

Zemaitis M.R. et al. (2023).

NIOSH (1998) Worker deaths by electrocution: A Summary of NIOSH Surveillance and Investigative Findings.

Electrical injuries can be differentiated between low-voltage (<600V) and high-voltage (≥600 V) injuries. Most micromobility products are designed to operate using low voltage (

e.g.,

60 VDC or less). Patients who experience low-voltage injuries may present with only minor or no skin burns. However, if there is prolonged contact or muscle tetany,

low voltage electrical energy can result in cardiac or respiratory arrest, arrhythmias (

e.g.,

ventricular fibrillation) or seizures. In addition to the characteristics of the electrical system, other factors can affect severity of injuries. For example, a victim contacting current in wet conditions may face a higher electric risk than in dry conditions.

Muscle tetany is an involuntary muscle contraction accompanied by overly stimulated peripheral nerves.

Zemaitis M.R. et al. (2023).

Depending on the severity of electrical injury, short-term immediate effects may include tingling or prickling

sensation, skin burns, headache, irregular heartbeat, seizures, and loss of consciousness. After the immediate injury, patients may experience long-term adverse effects, such as post-traumatic stress disorder (PTSD), depression, anxiety, insomnia, reduced attention span, and panic attacks.

The skin has the highest electrical resistance and tends to suffer the greatest level of damage (

i.e.,

skin burns). The electric resistance of the skin may prevent severe internal damage from the electric shock. Low skin resistance due to the presence of water or damaged skin may result in less severe skin burns, but a larger amount of electrical energy may be transferred to internal tissues leading to a higher risk of internal tissue damage.

Eagle R. How various levels of electric shocks affect the body and how to recover. MedicalNewsToday, available at:

https://www.medicalnewstoday.com/articles/electric-shock

(January 11, 2024).

Zemaitis M.R. et al. (2023).

E. Availability of Incident Data

Upon publication of this NPR in the

Federal Register

, CPSC will make available for review and comment the CPSRMS and NEISS incident reports relied upon and discussed in this NPR, to the extent allowed by applicable law, including any IDIs conducted by CPSC. Upon publication of this NPR, these data can be obtained by submitting a request at

https://forms.office.com/g/2ubiRFZxfw.

If you do not receive access to the data within one business day after submitting your request, or if you have any issues accessing the data, please contact the phone number or email address listed in the

FOR FURTHER INFORMATION CONTACT

section at the beginning of this NPR.

F. Recalls, Unilateral Press Releases, and Enforcement Letters

Since 2016, consumer use of micromobility products has greatly expanded, as has CPSC's engagement to mitigate the associated health and safety risks. This section of the preamble summarizes CPSC's efforts to inform industry about, and protect consumers from, associated fires, explosions, gas releases, burns, overheating, and smoke inhalation risks. From January 1, 2016, through November 30, 2024, CPSC conducted 29 voluntary recalls involving micromobility products associated with fire, overheating, and smoke inhalation hazards. Table 5 summarizes CPSC recalls.

BILLING CODE 6355-01-P

EP24JN26.035

EP24JN26.036

EP24JN26.037

BILLING CODE 6355-01-C

Additionally, during this same period CPSC issued nine press releases warning the public to stop using lithium-ion batteries and micromobility products because of associated safety hazards, such as fires, overheating, and smoke inhalation. Table 6

lists such press releases.

When the recall press release delineates the approximate number of recalled units, number of incidents, or number of injuries by country, this summary only includes the reported United States values.

https://www.cpsc.gov/Recalls/2016/Hype-Wireless-Recalls-Self-Balancing-Scooters-Hoverboards

https://www.cpsc.gov/Recalls/2016/Keenford-Limited-Recalls-Self-Balancing-Scooters-Hoverboards

https://www.cpsc.gov/Recalls/2016/Razor-Recalls-Self-Balancing-Scooters-Hoverboards

https://www.cpsc.gov/Recalls/2016/Overstock-Recalls-Self-Balancing-Scooters-Hoverboards

https://www.cpsc.gov/Recalls/2016/Digital-Gadgets-Recalls-Self-Balancing-Scooters-Hoverboards

https://www.cpsc.gov/Recalls/2016/Self-Balancing-Scooters-Hoverboards

https://www.cpsc.gov/Recalls/2016/Swagway-Recalls-Self-Balancing-Scooters-Hoverboards

https://www.cpsc.gov/Recalls/2016/Hoverboard-LLC-Recalls-Self-Balancing-Scooters-Hoverboards

https://www.cpsc.gov/Recalls/2016/Yuka-Clothing-Recalls-Self-Balancing-Scooters-Hoverboards

https://www.cpsc.gov/Recalls/2016/PTX-Performance-Products-Recalls-Self-Balancing-Scooters-Hoverboards

https://www.cpsc.gov/Recalls/2017/World-Trading-Recalls-Orbit-Self-Balancing-Scooters-and-Hoverboards

https://www.cpsc.gov/Recalls/2017/Boosted-Recalls-Electric-Skateboards

https://www.cpsc.gov/Recalls/2017/Vecaro-LifeStyle-Recalls-Self-Balancing-Scooters-Hoverboards

https://www.cpsc.gov/Recalls/2017/iRover-Recalls-Self-Balancing-Scooters-Hoverboards

https://www.cpsc.gov/Recalls/2018/Smart-Balance-Wheel-SelfBalancing-ScootersHoverboards-Recalled-by-Salvage-World-Due-to-Explosion-and-Fire-Hazards

https://www.cpsc.gov/Recalls/2018/Sonic-Smart-Wheels-SelfBalancing-ScootersHoverboards-Recalled-by-Dollar-Mania-Due-to-Explosion-and-Fire-Hazards.

https://www.cpsc.gov/Recalls/2018/Tech-Drift-Recalls-SelfBalancing-ScootersHoverboards-Due-to-Fire-and-Explosion-Hazards

https://www.cpsc.gov/Recalls/2018/iLive-SelfBalancing-ScootersHoverboards-Recalled-by-Digital-Products-Due-to-Fire-Hazard

https://www.cpsc.gov/Recalls/2018/iHoverspeed-SelfBalancing-ScootersHoverboards-Recalled-by-Simplified-Wireless-Due-to-Fire-Hazard

https://www.cpsc.gov/Recalls/2018/Go-Wheels-SelfBalancing-ScootersHoverboards-Recalled-by-Four-Star-Imports-Due-to-Fire-and-Explosion-Hazards-Sold-Exclusively-at-Village-Mart

https://www.cpsc.gov/Recalls/2018/Drone-Nerds-Recalls-SelfBalancing-ScootersHoverboards-Due-to-Fire-and-Explosion-Hazards

https://www.cpsc.gov/Recalls/2021/Specialized-Bicycle-Components-Recalls-Electric-Mountain-Bike-Battery-Packs-Due-to-Fire-and-Burn-Hazards-Recall-Alert

https://www.cpsc.gov/Recalls/2021/Razor-USA-Recalls-GLW-Battery-Packs-Sold-with-Hovertrax-2-0-Self-Balancing-Hoverboards-Due-to-Fire-Hazard

https://www.cpsc.gov/Recalls/2023/E-Bikes-Recalled-Due-to-Fire-Explosion-and-Burn-Hazards-Distributed-by-Ancheer

https://www.cpsc.gov/Recalls/2023/eWheels-Recalls-Gotway-and-Begode-Unicycles-Due-to-Fire-Hazard

https://www.cpsc.gov/Recalls/2023/E-Bikes-Recalled-Due-to-Fire-and-Burn-Hazards-Distributed-by-Gyroor-Recall-Alert

https://www.cpsc.gov/Recalls/2023/Jetson-Electric-Bikes-Recalls-42-Volt-Rogue-Self-Balancing-Scooters-Hoverboards-Due-to-Fire-Hazard-Two-Deaths-Reported

https://www.cpsc.gov/Recalls/2024/DGL-Group-Recalls-Hover-1-Helix-Hoverboards-Due-to-Fire-Hazard

https://www.cpsc.gov/Recalls/2024/Pacific-Cycle-Recalls-E-Bikes-Due-to-Fire-Hazard

EP24JN26.038

Finally, CPSC's Office of Compliance and Field Operations issued two enforcement letters advising manufacturers and importers of micromobility products to address fire hazards associated with such products to meet the requirements in the applicable voluntary standards. Table 7 describes these two letters.

When the press release delineates the number of incidents or number of injuries by country, this summary only includes the reported United States values.

https://www.cpsc.gov/Newsroom/News-Releases/2017/following-fatal-house-fire-cpsc-warns-consumers-to-stop-using-layz-board-hoverboards-0

https://www.cpsc.gov/following-second-house-fire-cpsc-warns-consumers-to-stop-using-layz-board-hoverboards

https://www.cpsc.gov/Newsroom/News-Releases/2020/CPSC-Warns-Consumers-Not-to-Charge-or-Use-New-High-Tech-X1-5-Hoverboards-Due-to-Fire-Hazard

https://www.cpsc.gov/Newsroom/News-Releases/2022/CPSC-Warns-Consumers-to-Immediately-Stop-Using-King-Song-Electric-Unicycles-Due-to-Fire-Hazard-Fire-and-Injuries-Reported

https://www.cpsc.gov/Warnings/2024/CPSC-Warns-Consumers-to-Stop-Using-Toos-Elite-Electric-Scooters-Due-to-Fire-Hazard-Two-Deaths-Reported

https://www.cpsc.gov/Newsroom/News-Releases/2024/CPSC-Warns-Consumers-to-Immediately-Stop-Using-EVERCROSS-EV5-Hoverboards-Due-to-Fire-Hazard-Sold-on-Amazon-com-and-Walmart-com

https://www.cpsc.gov/Newsroom/News-Releases/2024/CPSC-Warns-Consumers-to-Stop-Using-Unit-Pack-Power-UPP-E-bike-Batteries-Due-to-Fire-and-Burn-Hazards-Risk-of-Serious-Injury-and-Death

https://www.cpsc.gov/Warnings/2025/CPSC-Warns-Consumers-to-Immediately-Stop-Using-Swagtron-SG-5-Swagger-5-Boost-Commuter-Electric-Scooters-Due-to-Fire-and-Burn-Hazards-Risk-of-Serious-Injury-and-Death

https://www.cpsc.gov/Business--Manufacturing/Business-Education/Business-Guidance/Hoverboards

https://www.cpsc.gov/Newsroom/News-Releases/2023/CPSC-Calls-on-Manufacturers-to-Comply-with-Safety-Standards-for-Battery-Powered-Products-to-Reduce-the-Risk-of-Injury-and-Death.

EP24JN26.039

IV. Voluntary Standards Description, Assessment, and Substantial Compliance

In this section of the preamble, we describe the requirements of each of the three voluntary standards CPSC proposes to incorporate by reference and assess the adequacy of each standard, including proposed modifications to these standards, to preliminarily determine whether the NPR would address the risks of injury with the associated hazards identified in section III of this preamble. Additionally, we discuss whether the micromobility products distributed in U.S. commerce substantially comply with the existing applicable voluntary standards.

A. eBikes—UL 2849-20

In January 2020, ULSE published UL 2849-20, the bi-national safety standard for eBike electrical systems, which is still the current version of this standard. The following discussion summarizes and assesses the requirements in UL 2849.

1. Scope and Definitions

Introduction: Scope.

Section 1 of UL 2849-20 sets forth the scope of the standard, which includes (i) the electrical system of eBikes, both Electrically Power Assisted Cycle (EPAC—pedal assist) and non-pedal assist, that are powered by a lithium-based, rechargeable battery, as well as (ii) any additional electrical components or systems required to demonstrate compliance.

Electrical systems covered by the UL 2849-20 include onboard components, meaning those installed on the eBike, and off board components, including chargers used to charge batteries both on and off the eBike. UL 2849-20 includes some mechanical requirements for the eBike that are not applicable to the identified electrical hazards and are not proposed to be incorporated by the proposed rule.

Sit-down products without functional pedals are classified as an eScooter.

Introduction: Components.

Section 2 of UL 2849-20 states that critical safety components covered in the standard must meet the requirements in the standard. Sections 2.2-2.4 provide general guidance regarding the proper use and application of a component within the eBike's electrical system.

Introduction: Definitions.

Section 5 of UL 2849-20 defines terms used in the standard, including, for example: battery management system (BMS), charger, eBike, and enclosure. Defined terms provide context and clarity to the construction, performance, and labeling requirements in UL 2849-20. Accordingly, the NPR proposes to incorporate all definitions in section 5 of UL 2849-20 into the mandatory rule without modification.

2. Construction Requirements

The second major section of the standard is “Construction,” which specifies assembly requirements for product components (

e.g.,

battery pack, motor, charger and wiring), subsystems (

e.g.,

definition of hazard voltage and energy levels), and safety considerations (

e.g.,

safety circuits and analysis and flammability) that ensure that the eBike electrical system is comprised of components that meet applicable safety standards (

e.g.,

the motor complies with UL 1004-1, Rotating Electrical Machines—General Requirements) and are assembled in accordance with industry best practices. To mitigate the associated eBike risks to consumers, the “Performance” section of UL 2849-20, described below in section IV.A.3 of this preamble, defines the test methods to validate composition of the overall electrical system and components under foreseeable use and misuse conditions.

Construction: 7 General.

Section 7 of UL 2849-20 specifies general construction of safe electrical requirements for eBikes. For example, section 7.3 of UL 2849-20 states that eBikes consist of both EPAC and non-EPAC types, and all eBikes must have functional pedals. Products without pedals are definitionally not eBikes and would be considered a sit-down eScooter subject to UL 2272. Also, section 7.3 states that motors on motor-assisted eBikes (EPACs) must stop their assist function when the rider stops pedaling, when reaching a manufacturer's pre-determined speed, or when the user applies the brakes, to ensure that the drive system only assists the rider in the EPAC mode of operation, as would be expected. Motors for non-EPAC eBikes are not required to disengage when the user stops pedaling, because the eBike in the non-pedal assist mode of operation is expected to provide motive power independently of the user pedaling. Also, UL 2849-20 states that non-EPAC eBikes can include an EPAC mode.

Section 7.4 requires the eBike electrical system to be assessed for safe operation for environmental conditions of maximum altitude (6562 feet), ambient temperatures from 32 °F to 104 °F, and ingress protection from water exposure (section 36). If electrical systems can safely operate beyond these environmental limits, UL 2849-20 requires the manufacturer to specify the acceptable limits and provide instructions to inform consumers of the actual range of operation.

Construction: 8 Power Levels.

Section 8 of UL 2849-20 defines thresholds for voltage, current, and energy levels associated with the eBike electrical system; systems that exceed these thresholds are potentially hazardous and require design considerations to protect the user. To mitigate these hazardous conditions, these parts or circuits require an enclosure and or electrical insulation to prevent a user from contacting the parts.

Staff have not identified electric shock incidents involving micromobility products in the data examined. However, at this time the majority of micromobility product batteries are rated below 60 VDC. As micromobility products become more powerful and extend the range of operation, battery packs may exceed 60 VDC and can present a greater shock hazard. Furthermore, chargers (both external and those integrated into the micromobility product) are powered from 120 VAC utility power. As with any 120 VAC-connected product, the inherent risk of electric shock while using a charger may be mitigated through design and construction techniques consistent with appropriate standard industry practices. Staff advise that the voltage and current limitations in section 8, in conjunction with other sections of the standard, are based on well-established consumer product safety best practices and adequate to address the shock and fire hazards associated with eBikes.

Construction: 9 Combination of Battery, Battery Management System and Charger.

Section 9 explains that a BMS can be either fully integrated into the battery pack or external to the battery pack. Additionally, section 9.2 of UL 2849-20 requires that all testing be performed with the actual battery, BMS, and charger recommended by the manufacturer. Staff advise that evaluating the BMS in conjunction with the battery and charger, as provided in section 9, is necessary to ensure that these subsystems work together to mitigate the risk of causing cell damage and thermal runaway.

Construction: 10 User Protection While Charging

—eBike battery packs are charged either while installed on the bike or while removed from the eBike, depending on the eBike. To ensure that consumers do not get shocked in the process of charging an eBike or battery pack, section 10.1 of UL 2849-20 requires batteries that are only intended to be charged when not installed on an eBike to have an inherent means to

ensure that the battery cannot be charged when installed on the product.

Also, UL 2849-20 requires that eBike batteries being charged when they are installed on the eBike must protect consumers from a shock hazard from any exposed conductive surfaces of the eBike during charging. To meet the requirement, manufacturers must use a protection system, such as double insulation systems or protective grounding, onboard the eBike. Finally, to prevent potential injury to consumers from inadvertent operation of the drive motor, eBikes must have a charger connect-interlock to prevent the motor from activating while a charger is plugged into an outlet. eBikes without an interlock must provide another means of preventing inadvertent motor activation, such as a switch to keep power from being applied to the motor drive circuit while charging the battery.

Section 10 of UL 2849-20 is adequate to protect consumers from electric shock and death during charging because the standard addresses potential electrical injuries during both on-board and off-board charging based on requirements that are well-known and tested in other similar voluntary standards. For example, the protective grounding requirement of section 10.2.3, the grounding and bonding requirement of section 10.2.4, and the double insulation requirement of section 10.2.5 are common to electrical standards and these requirements are contained in many electrical standards, including UL 2580 and in UL 2594—

Electric Vehicle Supply Equipment.

Construction: 11 Battery Packs—

Addressing one of the hazard patterns identified above (table 4, unsafe battery) to ensure safe use of battery packs, section 11 of UL 2849-20 requires that lithium-ion battery packs comply with UL 2271-23 or UL 2580-22, Batteries for Use in Electric Vehicles.

UL 2271-23 and UL 2580-22 address the risk of thermal runaway and fire in a battery pack used in a motive platform by requiring:

•

Protective circuits

(

i.e.,

BMS) that shut down the charging or discharging of a battery if the normal limits of cell voltage, current, or temperature are exceeded;

•

Mechanical and environmental tests,

such as vibration endurance, drop, crush, thermal cycling, immersion and external fire exposure, to ensure battery packs can safely withstand a reasonable range of operating conditions;

•

Thermal cycling

to evaluate the ability of the battery pack of the eBike to withstand rapidly changing temperatures such as those encountered by moving a battery pack from an unheated garage in winter into a heated house;

•

Secondary lithium cell

manufacturing production line testing to ensure sufficient safety measures that mitigate internal short circuits, overcharge, crush, impact, mechanical shock, vibration, heating and other hazardous conditions during the life of the cells; and

•

Single cell failure mitigation requirement

to prevent a significant external hazard from a thermal runaway failure spreading to neighboring cells that could lead to a thermal runaway of that cell.

These UL standards are adequate to address the risk of thermal runaway because each has a BMS or protective cell requirement that provides for shut off of the electrical circuit if an individual battery or battery pack is operating outside of its safe operating region. Cutting off the circuit as soon as the battery closely approaches the limit of its safe operating range limits the progression of the underlying chemical reactions contributing to thermal runaway and reduces the probability of a hazardous thermal event. Each of these UL component standards also contains individual cell and battery pack enclosure requirements, and mechanical and environmental tests to simulate use and abuse of the battery/electrical system. Batteries complying with UL 62133-20, Secondary Cells and Batteries Part 2: Lithium Systems or UL 2054-21, Household and Commercial Batteries are also permitted to be used but must pass the tests in section 11.2 of UL 2849-20, which evaluate the battery/BMS to ensure it safely withstands normal and foreseeable misuse conditions for eBike electrical systems. Accordingly, incorporating these requirements into the rule improves the total safety of the eBike electrical system.

One of the hazard patterns identified in the incident data (table 4) is tampering. Section 11 of UL 2849-20 is not adequate to address the risks associated with users accessing the battery compartment. Consumers may attempt to modify or replace battery packs, including individual cells, even though they are not intended to be replaced or modified by the consumer. For example, in IDI No. 220908CCC1340, a consumer opened an eSBscooter and removed the battery pack. Although the incident product was an eSBscooter, this battery modification risk applies to all micromobility products within the scope of the rule, including eBikes.

To address this risk, the NPR proposes an additional requirement in relation to section 11 of UL 2849-20 that would reduce the likelihood of consumers easily accessing the battery compartment using common household tools, such as a flat blade or Philips head screwdriver. The new requirement, as stated in proposed § 1265.2(b)(1), would require a battery compartment to be inaccessible using simple household tools or to be ultrasonically welded or secured by equivalent means, such as adhesives compliant with UL 746C or tamper-proof screws.

Construction: 12 Safety Circuits and Safety Analysis

—To address one of the hazard patterns identified in the incident data (table 4, Unsafe Charging and Discharging), section 12 of UL 2849-20 requires the manufacturer to perform a safety analysis of their product to determine the specific fire and shock risks. This analysis sets the testing parameters such as the maximum charging voltage and current and the maximum temperature of the battery. The safety analysis must show that the BMS will limit or shut down the charging or discharging if normal limits of the battery are exceeded. The analysis is used to determine the electrical specification in the Performance section of UL 2849-20. Finally, the safety analysis ensures that protective circuits monitor events such as maximum assist speed and cutoff assistance due to braking, to mitigate the risk of thermal runaway. Staff advise that the required safety analysis in section 12 of UL 2849-20 is necessary to ensure that a BMS or other critical protective circuit addresses the potential hazards associated with eBike electrical system performance. The required evaluation and the described methods have been key elements of many other electrical voluntary standards, such as section 6.6.4 of UL 2054 and section 13 of UL 2580.

UL 2054 was published in May 1997 and UL 2580 was published in October 2011; both predate UL 2849-20.

Construction: 13 Enclosing and Insulating Hazardous Parts

—To reduce the risk of electric shock and thermal runaway that can lead to fires, section 13 of the UL 2849-20 requires eBikes to have one or more enclosures that contain all hazardous live electrical parts, including battery packs. Required enclosures must have sufficient strength and rigidity to withstand the potential physical abuse associated with the intended use of eBikes. This section sets forth requirements for the types and durability of materials for these enclosures, including nonmetallic and metallic materials, and criteria to

determine the suitability of polymeric materials, gaskets, and seals.

For example, non-metallic materials must have a minimum flame rating and consider suitability factors such as: resistance to impact; crush resistance; abnormal operations; severe conditions; and mold stress relief distortion. The enclosure itself must also be subject to the impact test in section 33 of UL 2849-20. Enclosures, frames, or handles on the eBike must not have sharp edges that would create a risk of injury during the normal use and maintenance of the product. Finally, openings in an enclosure must be designed to prevent inadvertent access to hazardous electrical parts.

UL 2849-20 also contains the following requirements that are consistent with other electrical standards, representing the best practices for safe electrical components, and CPSC preliminarily assesses that these requirements provide adequate protection to the consumer.

Construction: 14 Mounting

—Section 14 of UL 2849-20 requires that components that are mounted on the eBike be subjected to the vibration test in section 38 of the standard, as described in section IV.A.3 of this preamble. Vibration tests are commonly used in other electrical standards, such as section 35 of UL 2580 applicable to lithium-ion batteries, to ensure that components and connections remain functional and within the safe operating envelope even when subjected to dynamic loading. Applying the vibration test to the battery/battery pack and the entire eBike thus addresses electrical shock and fire hazards.

Construction: 15 Printed Wiring Boards

—Section 15 of the UL 2849-20 requires printed wiring boards to comply with the requirements in UL 796, and to have a flammability rating as described in section 17 of UL 2849-20. Staff advise that this requirement is adequate to address flammability and construction risks associated with printed wiring boards, and that this requirement is consistent with other electrical standards that reference UL 796 to establish safety requirements for printed wiring boards.

Construction: 16 Spacings and Separation of Circuits

—To prevent electrical shocks and fires, section 16 of UL 2849-20 requires physical spacing between parts of opposite polarity. Proper spacings prevent a short circuit,

i.e.,

an unintentional connection that draws excess current in the circuit and produces extreme heat, stresses components/wires, and can cause fires. As the voltage between two electrical points increases, the distance between them must comply with section 16 to prevent arcing, which could create an electrical shock and/or fire hazard. Section 16 of UL 2849-20 outlines what the minimum physical spacing must be, both through air and over-the-surface. Staff advise that the requirement for electrical spacings and table 16.1 are common electrical construction requirements that are consistent with other electrical standards and have been effective in preventing short circuits that can lead to fires.

Construction: 17 Flammability

—To ensure that nonmetallic eBike parts do not propagate flames or fire, section 17 of UL 2849-20 requires such nonmetallic materials used for enclosures, internal parts, or internal parts of components, to meet the flammability requirement specified in UL 94. UL 94 specifies test procedures to classify polymeric materials based on their vertical flammability performance. The ratings are V-2, V-1, and V-0 in order from least to most flame resistant. These ratings are based on the amount of time it takes for the test flame to extinguish, the afterglow to disappear, and whether tissue paper ignites under the test sample. Staff advise that the electrical industry has relied on the flame ratings in UL 94 since the first edition of that standard in 1972, and that the industry has relied on V-1 rated plastics for electrical enclosures as a suitable means of fire containment for more than 50 years. However, stakeholders have noted concerns with adverse health effects from the application of some flame retardant chemicals in plastics and reported that plastic battery enclosures using flame retardant plastic are ineffective in containing a lithium-ion battery fire and therefore unnecessary.

As such, CPSC seeks comments on use of flame-resistant plastic for battery enclosures.

January 10, 2024, CPSC staff Discussions with Green Science Policy on Lithium-Ion Battery Standards

https://www.cpsc.gov/s3fs-public/Green-Science-Policy-Meeting-Log.pdf?VersionId=sHgYg9z5yBmsMgQD9W1I9zpheKcysF.A.

Construction: 18 Internal Wiring and Terminals

—Section 18 of UL 2849-20 requires wiring used in an eBike electrical system to be insulated and acceptable for the purpose used, to prevent electric shock and fires. This means that manufacturers must consider the voltage, temperatures, and conditions of use. The wiring must be routed and reliably secured to the eBike to reduce excessive strain on the wires and to prevent loosening of wire connections and damage to insulation during use of the eBike. External terminals, meaning terminals that could be exposed to contact by the consumer and could be used for charging, must be designed to prevent misalignment, disconnection, or inadvertent short circuiting. Charging terminals must be designed to prevent misalignment or short circuiting when connected to the charging equipment. Any terminals presenting hazardous voltage must be designed to prevent consumer access and must not be able to be short-circuited by external metal parts. Wiring that may be flexed during operation must comply with the Flexing Test in section 35 of UL 2849.

Staff advise that the wiring requirements in section 18 are adequate to address the risk of shock and fire from wiring that is not suitably routed, secured, and connected. Additionally, the temperature and overcurrent requirements of this standard address the ability of the wiring to carry the intended current without overheating of the eBike electrical system.

Construction: 19 Overcurrent Protection

—To prevent overheating of the eBike electrical system, section 19 of UL 2849-20 requires that power, control, and auxiliary circuits be sufficiently sized to prevent overheating of the smallest conductor. UL 2849-20 requires compliance with two applicable consensus standards for components: positive temperature coefficient (PTC) overcurrent protection must comply with UL 60730-1, and fuses must comply with UL 248-1. These standards have long been commonly used in electrical system requirements, such as UL 1598, section 6.6, covering fuses used in Luminaires.

Construction: 20 Motors and Motor Controllers

—To mitigate the potential of shock and fires from overheating motors and motor controllers, section 20 of UL 2849-20 requires that motors must not overheat and motors in hazardous voltage circuits, meaning those that have either an input voltage or output voltage considered hazardous according to UL 2849-20, must comply with UL 1004-1 or CSA C22.2 No. 100. If the motor is not in a hazardous circuit, then motors are required to comply with either UL 1004-1 or CSA C22.2 No. 100, or UL 2849-20 requirements. CPSC preliminarily assesses that section 20 is adequate to mitigate shock and fires associated with overheating motors and motor controllers because there is a reference standard covering the entire motor assembly and the motor assembly is tested as part of an eBike electrical system within the requirements of UL 2849-20.

Construction: 21 Operator Interface

—Operator interface refers to the part of the eBike that the user engages with by

touching or contacting a screen, switch, or other mechanical or electrical switch, or lever, to actuate the motor or other electrical controls of the eBike. Because the consumer interacts with the operator interface, section 21 of UL 2849-20 requires hazardous electrical parts to be adequately enclosed or protected to mitigate injury. If the consumer has access to hazardous electrical parts, UL 2849-20 requires that such parts be enclosed as described in section 13 of UL 2849-20; the interface must also comply with section 21.2, requiring compliance with UL 60950-1 or UL 62368-1, if the interface has battery circuits with a touchscreen or high voltage backlights. CPSC preliminarily determines that the requirement in section 21 is adequate to protect consumers from shock due to exposure to hazardous electrical parts through enclosure or testing to referenced electrical consensus standards, which are commonly used in electrical standards.

Construction: 22 Grounding and Bonding

—Grounding of electrical current routes hazardous energy away from the consumer to prevent electric shocks during charging and to facilitate tripping the branch circuit breaker to remove power and prevent overheating if a ground fault occurs,

i.e.,

if a metal part that is not part of a circuit and not intended to be electrically energized, becomes energized accidentally. Section 22 of UL 2849-20 requires that eBikes use a grounded and bonding system to achieve this protection. This requirement applies to both on-board and off-board chargers (separate power supply). Sections 22.2.1 through 22.2.11 reference and describe adequate grounding and bonding requirements used in other electrical consensus standards for this purpose. The requirements in this section ensure that the eBike electrical system is designed and manufactured with properly rated and integrated components and enclosures. Accordingly, incorporating these requirements into the rule is adequate to ensure the overall safety of the eBike electrical system.

CPSC preliminarily assesses that the grounding requirement in UL 2849-20 is based on well-established consumer product safety best practices, included in consensus standards used in the industry to address shock hazards such as UL 2594,

Electric Vehicle Supply Equipment,

and adequate to address the shock and fire hazards associated with eBikes.

Construction: 23 Chargers

—The charger provides an electrical voltage which, if properly matched to the maximum battery pack charging voltage, will safely charge the battery using an electrical current that is within the voltage, current, and temperature specifications of the cells contained in the battery pack. UL 2849-20 requires compliance with one of four consensus standards for power supplies: UL 1012, UL 1310, UL 60950-1, or UL 62368-1.

These power supply safety standards include requirements to ensure the safety of the charger with respect to its operation,

i.e.,

a charger that is compliant with these standards will not itself pose a risk of fire or shock to users during its normal and abnormal conditions. These standards find common use across a wide range of products including laptop computers. CPSC preliminarily assesses that section 23 of UL 2849-20 is adequate to protect consumers from electrical shock and fire during charging because the charger requirements in the reference standards above also address electric shock and fire.

UL 1012—

Power Units Other Than Class 2,

UL 1310—

Class 2 Power Units,

UL 60950-1—

Information Technology Equipment—Safety—Part 1: General Requirements,

or UL 62368-1—

Audio/Video, Information and Communication Technology Equipment—Part 1: Safety Requirements.

Construction: 24 Electrical Cables and Connectors Between the eBike and the Equipment

—Electric cables can transport hazardous energy to consumers if the cables break or if they are not constructed to carry the intended electrical energy. Accordingly, eBike cables and connectors must be suitably rated for use in the eBike. To address one of the hazard patterns identified in the incident data (table 4, Unsafe Charging and Discharging), and to prevent electric shock and fire hazards associated with electrical cables and connections, section 24 of UL 2849-20 requires that cables used to connect off board equipment to the eBike, such as a home eBike wall mount with integral charging port/connector, be permanently connected to the charger or connected to the charger with a connector that complies with section 24.2, which requires compliance to UL 2251 or UL 1977. The cable itself must comply with UL 62, which requires cables to be properly rated for anticipated current and to be suitably rated for the voltage and temperature used for the specific eBike. The conductor, which is the metal part of the wire inside the insulation material, must be sufficiently sized to conduct the anticipated current. Connectors used to connect off-board equipment to the eBike, such as such a charging dock or right-angle charging adapter, must comply with UL 2251 or UL 1977, and the connectors must be suitably rated for the specific eBike use.

Based on staff's analysis, CPSC preliminarily assesses that section 24 is adequate to protect consumers against exposure to hazardous energy from cables and connectors because the requirements are based on long-standing effective consensus standards. UL 1977 is an industry-recognized standard for electrical connectors and UL 2251 expands these requirements to include additional electrical equipment charging scenarios.

Construction: 25 Supply Connections

—To address one of the hazard patterns identified in the incident data (table 4, Unsafe Charging and Discharging), section 25 of UL 2849-20 requires that chargers and all other equipment located off board the eBike that is involved in transferring power to the eBike must comply with the applicable consensus standard for that equipment. CPSC preliminarily assesses that this requirement is adequate to address the associated risk of injury.

3. Performance Tests

The third major section of the standard is “Performance,” which establishes test methods and pass-fail criteria for the electrical system of the eBike. These tests stress the electrical system, including the battery and other electrical components, and require that the electrical system stay within its specifications (as determined in section 12) during normal and abnormal operations. Tests identified in the Performance section are either conducted to stress the battery pack, or the remainder of the electrical system of the eBike. Battery-specific tests may be waived when the test contains an exception for compliance with section 11.1(a) or 11.1(b).

Performance: 26 General

—Section 26 of UL 2849-20 requires that performance tests be conducted on representative electrical systems of eBikes and outlines the basic testing required for determining battery pack compliance and for determining whether the battery pack is operational, before proceeding to other tests that may use the same sample. Staff advise that these requirements are adequate tests to ensure that hazardous outcomes such as fire or shock do not result from exposures to foreseeable conditions such as excessive temperature or current. Further, the range of temperatures, currents, abnormal operations, etc., represented in section 26 adequately address the failure modes seen in incidents and known to exist

from engineering experience with other products.

Performance: 27 Input Test

—Staff identified unsafe charging and discharging as a hazard pattern in the incident data (see table 4). eBike charging is done by the consumer, typically while the eBike is unattended, even when against the manufacturer's recommendation. As such, the amount of energy going into the eBike during charging should not be hazardous to the consumer or create a fire hazard. To address this risk of injury, section 27 of UL 2849-20 requires that the input current to an eBike while charging a fully discharged battery should not be more than 110 percent of the manufacturer-rated input current. For an external charger, the measured current shall not exceed the charger's output current rating.

Charging a battery too fast or using more current than anticipated could cause cells to overheat, particularly if the additional current allows the cells to charge faster than the safe operating region as defined by the cell's electrical specification. The charger plays a critical role by making sure that the output current of the charger limits the amount of energy going into the battery pack for safe charging and no increased risk of fire. Based on staff's review, this test is adequate to protect against possibly overcharging cells, which would increase the risk of thermal runaway.

Performance: 28 Temperature Test

—To address one of the hazard patterns identified in the incident data (table 4, unsafe charging and discharging), section 28 of UL 2849-20 ensures that safety critical components in the eBike electrical system and the cells within the battery pack do not exceed their temperature ratings while the eBike is operating at the maximum rider weight and power and also when being charged. Exceeding the temperature ratings could damage a component and degrade its performance and create an unsafe condition. As such, the standard ensures that cells are monitored to ensure that they do not exceed their voltage, current and temperature ratings. Also, these tests measure user-accessible surfaces on the eBike during the same operating conditions to verify that the remain below acceptable limits to prevent thermal contact burns. This test uses two procedures. In the first, the battery, separate from the bike, is evaluated during charging from full discharge and during discharge at a current representing the manufacturer's rated maximum rider weight and operating conditions until fully discharged in accordance with the manufacturer's specified final voltage. The other procedure tests the eBike with a power supply representing the battery pack under a mechanical load reflecting the manufacturer's rated maximum rider weight and operating conditions (such as speed, rider weight, or slope angle). This test ensures that the drivetrain components do not exceed their rated temperatures and fail, producing a risk of fire, shock, or thermal burns conditions.

The discharge/charge cycles specified in sections 28.4 and 28.5 do not indicate a timeframe between the termination of the full discharge and the start of the next charge cycle. It is foreseeable, however, that a user will ride an eBike or other micromobility product until the battery dies and then immediately plug in the product to recharge. In this situation, the battery cells may be at a temperature higher than the manufacturer-specified maximum charging temperature. In IDI 240112CCC1726, for example, the original charger that came with the eSBscooter was lost, and the consumer bought a replacement charger and used it a number of times without incident. On the day of the incident, after riding the eSBscooter until its battery depleted, the consumer placed his eSBscooter on the charger in the garage. After a short period of time the consumer's brother noticed smoke in the garage. The fire investigator assessed that the hoverboard had exploded and a fire ensued.

To address worst-case temperature scenarios such as this, where a battery is charged immediately after discharge, the NPR proposes a performance requirement based upon section 28.5 of UL 2849-20 but further specifies that prior to the second and third charge/discharge cycle in the test, the second charge cycle be initiated immediately after the first full discharge. This modification tests whether the BMS prohibits charging the battery if the cell surface temperature exceeds the specified upper limit. This test is an existing requirement in UL 2272-24 but not UL 2849-20.

Performance: 29 Isolation Resistance Test

—To prevent electric shock to consumers through contact with any accessible part of the eBike as well as thermal runaway, section 29 evaluates electrically insulating materials to ensure that they have a minimum level of resistance and do not conduct electricity that could pose a risk of shock to a user contacting the insulation, or a short circuit that could cause overheating and fire. This test also ensures that the electrically insulating materials do not absorb moisture that could decrease resistance. Moisture resistance is assessed in conjunction with the section 31 humidity conditioning. CPSC preliminarily assesses that these requirements are adequate to protect consumers from both shock and from risk of overheating and fire.

Performance: 30 Dielectric Strength Test

—To prevent an electric short that can result in a shock or fire hazard as well as thermal runaway, section 30 of UL 2849-20 prescribes a standard diagnostic test procedure in which the electrical insulation and spacing between parts are evaluated by imposing a high voltage on the circuits, looking for weaknesses in the insulation or opposite polarity parts too close to each other. Inadequate electrical insulation and spacing may result in short circuits and fire, or inadequate user protection and electric shock. The test occurs after other electrical tests, to make sure that the underlying test condition does not result in the consumer being exposed to an electrical hazard. Staff advise that the test method is based on well-established consumer product safety best practices, included in voluntary consensus standards such as UL 2580, covering Batteries for Use in electric Vehicles, and is adequate to address the shock and fire hazards associated with eBikes.

Performance: 31 Humidity Conditioning Test

— To address thermal runaway and shock, section 31 of UL 2849-20 requires eBikes to comply with the requirements for the Dielectric Strength Test, in section 30, and the Isolation Resistance Test, in section 29, following exposure to air having a relative humidity of 88 ± 2 percent at a temperature of 32 ± 2 °C (90 ± 3.6 °F). The purpose of this test is to ensure that the eBike electrical system does not present a fire or shock hazard due to environments with high temperature and high humidity. Increased humidity lowers the surface resistance of non-metallic parts. Testing for increased humidity provides a critical condition for evaluating the minimum resistance value of the electrical system, and CPSC preliminarily concludes that section 31 adequately addresses the hazards associated with this condition.

Performance: 32 Abnormal Operation Tests

—To address unsafe charging and discharging, section 32 of UL 2849-20 is a series of nine tests for eBikes to evaluate the potential consequences to consumers of product or component failure. During the tests in sections 32.2 through 32.10, the eBike must not emit flames or molten metal, or become a risk of fire or electric shock. Section 32 requires the Abnormal Operation Tests

to be conducted on separate eBikes. Following each test, any hazardous voltage circuits are also subjected to the Isolation Resistance Test in section 29 (without humidity conditioning) or the Dielectric Strength Test in section 30. Each test must be continued until further change as a result of the test condition is reduced significantly. These are stress tests to ensure safe operation of the electrical system during these extreme but foreseeable operating conditions.

Section 32.1,

General,

defines the failing criteria that constitute a fire or shock risk as result of the abnormal operation tests being conducted.

Section 32.2,

Overcharging,

tests assess the safe operation of the electrical system due to a component failure in the charging protection circuit that allows the battery to be overcharged by 10 percent, which is consistent with the same requirement in UL 2580, which is a well-established standard for electric vehicle batteries. As discussed elsewhere, overcharging may lead to thermal runaway. An eBike that uses a battery that meets the requirements in UL 2271-23 or UL 2580 is not subjected to this testing because it already meets this requirement.

Section 32.3,

Component Fault,

assesses the safety impact of the failure of a single electrical component in the input and output power circuits. This includes capacitors, diodes, or solid-state devices (

e.g.,

transistors) that may fail. This test assesses the fault tolerance of the input and output circuits to ensure that a single component failure will not create a risk of fire, shock, or injury.

Section 32.4,

Forced Ventilation/Blocked Ventilation,

assesses eBikes with forced and blocked ventilation for hazardous conditions to consumers. The test requires the eBike to be operated with a fully charged battery supplying electrical energy to the fan/ventilation motor while the motor is in a locked state to determine whether the electrical system shuts down prior to overheating or electrical shock hazard. An eBike electrical system that relies on a fan or fans and vents for cooling is tested with the ventilation fans disabled and the ventilation openings blocked to ensure that these foreseeable fault conditions do not result in a risk of fire, shock, or injury.

Section 32.7,

Short Circuit,

evaluates the ability of the eBike battery pack to withstand short circuiting with a fault in the charging control circuit. For these tests the battery pack is short circuited, while each protective device in the charge control circuitry is shunted to simulate its failure. Examples of protective devices include overcurrent protection and temperature limiting fuses. An eBike that uses a battery that meets the requirements in UL 2271-23 or UL 2580 is not subjected to this testing because it already meets this requirement.

Section 32.8,

Imbalanced Charging,

is a test on battery packs, which consists of a number of cells connected electrically in series and parallel. The cells are intended to all be at the same voltage during charging and discharging. However, over time some cells may lose their capacity more quickly than others and may not hold their charge as long. When one or more cells are at a different voltage from the remaining cells in the pack, this is an imbalance, creating the potential for overheating when charging or discharging. This testing forces a cell or cell block to be at a 50 percent higher SOC than the rest of the cells and then charges the pack to ensure that the imbalanced cells do not become overcharged. This is the same procedure as in UL 2580. A battery that meets the requirements in UL 2271-23 or UL 2580 is not subjected to this testing because it already meets this requirement.

Section 32.9,

Shock,

ensures that the battery pack does not pose a risk of fire or electrical shock as a result of a mechanical shock or impact. The test requirements are the same as those in UL 2580-22. A battery that meets the requirements in UL 2271-20 or UL 2580-22 is not subjected to this testing because it already meets the requirement.

Section 32.10,

Thermal Cycling,

evaluates the ability of the battery pack to withstand rapidly changing temperatures such as moving a battery pack from an unheated garage in winter into a heated house. The battery is placed in a conditioning chamber at one extreme of its recommended ambient temperature range for at least 6 hours, then switched to its opposite extreme rating in 15 minutes or less for five cycles at each temperature extreme. At the end of the thermal cycling the battery is subjected to a discharge/charge cycle. The thermal cycling shall not cause the battery to create a risk of fire or shock. A battery that meets the requirements in UL 2271-23 or UL 2580 is not required to be subjected to this testing because it already meets this requirement.

The abnormal operation tests in section 32 outline a program for stressing batteries of eBike electrical systems that staff advise is appropriate. The tests are waived for previously qualified micromobility battery packs.

In addition, the following tests contribute to the overall safety of the eBike electrical system, ensuring that it is designed and manufactured in accordance with best industry practices with properly rated and integrated components and enclosures.

Section 32.5,

Locked Rotor Motor,

evaluates whether the drive motor can safely withstand a locked rotor condition, which would simulate a motor becoming jammed and not able to spin. The motor must not exceed temperatures that could ignite tissue or cheesecloth. The motor rotor is locked for seven hours and temperatures monitored. The motor can be tested on the bike or removed if the motor temperatures cannot be measured with the motor installed. Motors that have already been tested to one of the equivalent UL 1004 series electric motor standards do not need to satisfy this test. This requirement is intended to ensure that a locked motor condition will not result in a fire that could propagate and ignite the battery.

Section 32.6,

Running Overload,

evaluates a motor's ability to safely withstand an overload condition in conditions such as going up a very steep grade, carrying a rider weighing more than the specified limit, or a failing wheel bearing. Similar to the locked rotor test, a motor that is not tested for compliance with one of the UL 1004 series electric motor standards must not exceed temperatures that could ignite tissue or cheesecloth. For this testing, which may be conducted with the motor removed from the vehicle, load is progressively increased until overload protection activates or the motor's windings fail. This requirement, too, is intended to ensure that a locked motor condition will not result in a fire that could propagate and ignite the battery.

Additional Requirement Addressing Incompatible Chargers

—UL 2849-20 does not address the risk of electric shock and fire associated with use of an aftermarket eBike charger that uses the same charging connector as the OEM charger but is configured in the opposite polarity,

i.e.,

the positive and negative contacts reversed. The reversed polarity of an aftermarket charger may result in a cell being exposed to an out-of-specification voltage, causing excessive current and possibly fire or damage to the cell. For example, in IDI 240112CCC3378, the consumer plugged in an aftermarket charger to an eSBscooter. The consumer smelled smoke and the eSBscooter emitted sparks after charging for approximately 30 minutes. An unsafe rapid discharge can occur if the charger's output connector polarity is the reverse of the

battery polarity. Although this incident occurred on an eSBscooter, this incident is also possible with eBike electrical systems if the charger connector polarity is reversed. Section 18.4 of UL 2849-20 requires the OEM eBike charger output connector polarity to match the micromobility battery polarity.

To address the unreasonable risk of injury and death associated with incompatible chargers with reversed polarity from the battery, the NPR proposes to add a reverse polarity test to section 32 of UL 2849-20. The test would require, while monitoring temperature, a reverse voltage to be applied to the eBike electrical system for 4 hours or until a fire or explosion occurs. The test would require that no reverse voltage be imposed on the battery cells. This would require the eBike's electrical system to have a means to prevent an incorrect charging polarity from damaging the battery pack.

Other Performance Requirements addressing Fire and Shock Hazards not associated with Battery Thermal Runaway

—The requirements below address fire and shock hazards not associated with battery thermal runaway and contribute to the overall safety of the eBike electrical system, ensuring that products are designed and manufactured in accordance with best industry practices with properly rated and integrated components and enclosures. Accordingly, incorporating these requirements improves the total safety of the eBike electrical system.

Performance: 33 Impact Test

—Section 33 of UL 2849-20 subjects an eBike to blows simulating objects hitting the eBike in intended and foreseeable misuse conditions, to determine whether such impacts pose a risk of electric shock or fire hazard to the consumer. Section 33 requires the battery enclosure to withstand an impact of 6.8 J (5 foot-pounds) by dropping a 535g (1.18 pound) steel ball onto the battery enclosure from a height of 1.29 m (51 inches). All exposed surfaces of the battery enclosure must be tested. Additionally, eBikes must not show signs of cracking or other deleterious effects from the oven conditioning and must not be distorted. After the impact test, any openings resulting from the test must be assessed for access to hazardous live parts. This impact test is commonly used in other electrical standards such as section 62.3,

Steel Sphere Impact Test,

in UL 1449, covering Surge Protective Devices. CPSC preliminarily assesses that the impact requirements are adequate to evaluate whether the eBike electrical system poses an electric shock or fire hazard to the consumer.

Performance: 34 Mold Stress Test

—Section 34 of UL 2849-20 tests for shrinkage or distortion of an eBike thermoplastic enclosure that could result in consumer exposure to hazardous parts or reduced electrical spacings. Fully discharged eBike samples must first be conditioned in an oven for seven hours. After removal from the conditioning oven and cooled to room temperature, each sample is subjected to the Isolation Resistance Test in section 29 (without humidity conditioning) or the Dielectric Strength Test in section 30, and there must be no damage of the eBike system enclosure that would allow access to parts of hazardous voltage, as tested by using the 2.5 mm diameter by 100 mm long rod described in UL 2271-23 and the articulate finger probe used in Figure 18.1 of UL 2849-20. Based on staff's review, CPSC preliminarily concludes that the requirements of the mold stress test are adequate at protecting the consumer from electrical shock because the requirements are based on well-established consumer product safety best practices and included in voluntary consensus standards such as UL 1449,

Surge Protective Devices.

Performance: 35 Flexing Test

—Section 35 of UL 2849-20 evaluates the protection of wiring that is subject to movement during use of the eBike to ensure that the wires do not fray and become damaged and pose a risk of fire or shock by creating conditions for an internal short. The moving part is flexed 500 cycles, then subjected to a dielectric voltage withstand test as in section 30 to assess the continued effectiveness of the electrical insulation properties of the wires. The wires are also visually inspected for any other signs of fraying or compromised insulation that would contribute to a possible short circuit between conductors of opposite polarity or to metal parts that are accessible to the user. CPSC preliminarily finds that this test is adequate to assess risks of fire and shock related to wire flexing because the test method is substantially similar to the flexing test in section 11.9,

Cord Sets and Power Supply Cords,

in UL 817, which has demonstrated value in protecting consumers.

Performance: 36 Ingress Protection Tests

—Section 36 of UL 2849-20 evaluates the ability of the eBike to withstand potential water exposure. The test requires the eBike battery enclosure be exposed to splashing water in accordance with the Standard for Degrees of Protection Provided by Enclosures (IP Code), IEC 60529, Tests for Protection Against Water Indicated by the Second Characteristic Numeral 4 (IPX4). IPX4 corresponds to a splash rating. If the equipment is operational after water exposure, a charge and discharge cycle is conducted. There should be no indication of shock or fire hazard. If the manufacturer intends for the eBike to withstand a higher level of water resistance, then the eBike shall be evaluated and marked accordingly. As discussed in the Marking and Instructions section below, the NPR additionally proposes that instructions must include warnings and appropriate actions that consumers should take to avoid injury in the event that an eBike submerges in the water.

Performance: 37 Permanence of Marking Test

—Section 37 of UL 2849-20 requires a test to determine the permanence of required marking and labeling adhered to the product surface, unless the labels already comply with UL 969, Marking and Labeling Systems (UL 969). The test requires soaking a cloth with water and then rubbing the label with the cloth for 15 seconds; the same test is then repeated using a cloth soaked with the petroleum spirit in section 37.3. After rubbing with water and the petroleum spirit, the label should not show evidence of damage, including curling, should still be legible, and should not be easily removable by hand. This test is commonly used in electrical standards relying upon product labeling to inform consumer about technical ratings and other safety information related to the safe use of electrical products, including UL 1449, the Standard for Surge Protective Devices, and ANSI/UL 1598-2021 & CSA C22.2 No. 250.0:21, the Standard for Luminaires. CPSC preliminarily assesses that the permanency requirement is adequate to ensure required markings and labels retain their utility after exposure to reasonably foreseeable environmental conditions.

Performance: 38 Vibration Test

—As stated in the discussion on section 14, components that are mounted on the eBike must be subjected to the vibration test in section 38 of the standard. CPSC preliminarily concludes that this test is adequate at assessing hazards related to vibration because vibration testing of the battery pack ensures minimum mechanical integrity of the components. Moreover, these tests are commonly used in other electrical standards, such as section 35 of UL 2580, which is applicable to lithium-ion batteries. Subjecting the entire eBike to the vibration test is a best practice to mitigate electrical shock and fire hazards and CPSC preliminarily assesses that it is necessary to ensure the battery pack maintains safe

operations after being exposed to dynamic loads expected during reasonably foreseeable use conditions.

Performance: 39 Strain Relief Test

—Section 39 of UL 2849-20 evaluates the strength of interconnecting cables to withstand pulling and pushing against electrical wires during eBike use, using a strain relief pull and push back test. The test is designed to determine whether the movement of conductors results in a reduction of electrical spacings or exposed electrical conductors, potentially creating an electrical shock or fire hazard. The strain relief test assesses whether an interconnecting cable is prevented from being pushed or pulled into the product through the cord entry hole, which could expose the cable to mechanical damage, high temperature, reduced spacings, or internal damage to connectors or components. This test to protect consumers from shock and fire hazards is commonly used in electrical standards, such as UL 1449, Surge Protective Devices, section 57, and has been widely accepted by industry.

4. Sections That Are Out-Of-Scope of the Proposed Rule

The NPR does not propose to require two sections of UL 2849-20 that address mechanical rather than electrical hazards associated with eBikes: section 40 of UL 2849-20,

Performance: Startup Assistance Mode Test,

which evaluates the eBike startup assistance mode; and section 41 of UL 2849-20,

Performance: Motor Assistance Control Test,

which assesses the motor assistance of EPAC eBikes.

On March 15, 2024, the Commission has issued an advance notice of proposed rulemaking concerning eBike mechanical hazards. 89 FR 18861.

5. Marking and Instructions

Marking: 42 General

—Section 42 of UL 2849-20 contains general marking requirements. Markings must be legible and have an adhesive backing compliant with UL 969 and CSA C22.2 No 0.15, or the label must comply with the permanency test in section 37. CPSC preliminarily assesses that these are adequate requirements to ensure permanency as the markings and labeling systems are referenced across not only UL standards, such as UL 507 Electric Fans and UL 749 Household Dishwashers, but also ANSI standards (

e.g.,

ANSI/OPEI B175.3 Internal Combustion Engine-Powered Hand-Held Grass Trimmers and Brushcutters, ANSI 325 Door, Drapery, Gate, Louver, Window Operators and Systems).

Marking: 43 Nameplate and Identification

—Section 43 requires eBikes to be marked with the manufacturer's name or other descriptive marking identifying the organization, part number, model number, electrical ratings, and date of manufacture. Section 43 also requires that if the product has been manufactured at more than one factory location, the markings must include a distinctive marking to identify that the product was manufactured in a particular factory. Based on staff's review, the above requirements are adequate to position consumers to order the correct replacement parts and respond to a recall when necessary. The requirement to display such product identifying information is consistent with other consumer product safety standards such as those for durable infant or toddler products.

Section 43.3 states that if an eBike is sold with a battery pack that has its battery management system residing in components or circuits outside the battery pack, then the eBike must display the following statement or an equivalent: “Use Only Charger (__).” The blank must contain identifying information for the charger. Section 43.4 requires that all external terminals and connections, including the battery terminals if the battery pack is not keyed,

be provided with identification and, if applicable, with polarity markings. These requirements reduce fire risk by informing consumers about the specific charger that is compatible with the eBike and accurately identifying the external terminals, connections, and polarity markings.

Keyed means the charging input connector is designed so that it fits into the micromobility product only one way.

Marking: Cautionary Markings

—Section 44 requires specific wording for cautionary markings on eBikes and specifies required text formatting. The primary voluntary consensus standard providing guidelines for the design of safety signs and labels for application to consumer products is ANSI Z535.4, American National Standard Product Safety Signs and Labels.

100

The ANSI standard includes recommendations for the design, application, use, and placement of warning labels. CPSC relies on ANSI recommendations when assessing the adequacy of warning design for voluntary standards, including this assessment of the warnings in UL 2849-20. The safety hierarchy or hazard control hierarchy is a priority scheme to address product hazards. The fundamental sequence of priorities in the safety hierarchy includes three approaches to address product safety: (1) design out the hazard; (2) guard against the hazard; and (3) warn about the hazard. For a warning to be effective, it must first capture the user's attention. People do not typically seek out warnings, therefore warnings must be located prominently and have design characteristics that make them stand out. Further, the content of the warning must motivate safe behavior.

101

When assessing the adequacy and efficacy of a warning, CPSC considers a warning's content, design, and location.

100

American National Standards Institute (2023). ANSI Z535.4. American National Standard for Product Safety Signs and Labels. Rosslyn, VA: National Electrical Manufacturers Association.

101

Laughery, K.R., & Wogalter, M.S. (2006). Designing effective warnings. In R. Williges (ed.) Reviews of Human Factors and Ergonomics, Vol. 2. (pp. 241-271), Santa Monica, CA: Human Factors and Ergonomics Society.

Section 44.1 describes specific wording to utilize in a cautionary marking and specifies text height requirements, such as requiring use of the word “CAUTION” or “WARNING,” and requiring that the letters shall not be less than 3.2 mm (

1/8

inch) high, and the remaining letters be at a minimum of 1.6 mm (1/16 inch) high. Although text sizes required by UL 2849-20 are within the dimensions suggested by ANSI Z535.4 for small products (table B1), eBikes are not small products. Therefore, the NPR proposes to increase the text size requirement to 5 mm (0.2 inch) for the signal words (

e.g.,

“WARNING”) and 2.5 mm (0.1 inch) for the remaining letters, which aligns with ANSI Z535.4 recommendation for a 2-feet viewing distance, which is a likely distance from which these warnings would be viewed.

Section 44.1 also states that “WARNING” or “DANGER” can be used as alternatives for “CAUTION.” Allowed signal words (

e.g.,

WARNING, DANGER, CAUTION) are commonly used signal words for cautionary markings in the safety literature, including ANSI Z535.4.

Section 44.2 requires that cautionary markings remain visible and legible during normal eBike operation and cannot be located on a removable component. If a marking appears on a removable component, removal of that part must impair the operation of the entire product; in addition, the marking must be visible and legible to the operator during normal operation of the unit. CPSC preliminarily assesses that the visibility requirement in UL 2849-20 is adequate to provide visible and legible cautionary markings because ANSI Z535.4 states that warnings must be placed so they are “readily visible to the intended viewer” and will “alert the viewer to the hazard in time to take

appropriate action” (section 9.1). However, the requirement for warnings to be visible and legible to the user while riding the eBike may not be appropriate for the battery-related warnings because research shows that most effective warnings are placed proximate to the hazard.

102

CPSC preliminarily determines that locations that are proximate to the battery would be more effective for warnings that are related to batteries and for the proposed warnings discussed below, the NPR proposes specific locations that may supersede 44.2.

102

Wogalter, M.S., Conzola, V.C., & Smith-Jackson, T.L. (2002). Research-based guidelines for warning design and evaluation. Applied Ergonomics, 33, 219-230.

https://doi.org/10.1016/S0003-6870(02)00009-1.

Section 44.3 of UL 2849-20 requires a replacement marking for user replaceable fuses. Either the fuse or fuse holder must be labeled if the fuse reduces the risk of fire or electric shock and the fuse is user replaceable. The marking must be readily visible during replacement of the fuse, consist of the word “WARNING,” and contain the following statement or equivalent: “Risk of Fire and Electric Shock—Replace Only With Same Type and Ratings of Fuse.” Warning information should include a description of the hazard and instructions for specific actions to avoid or prevent the hazard.

103

Staff assess that the warning content of the user replaceable fuse label includes both a description of the hazard and how to avoid it and is therefore clear and adequate. In addition, the placement for fuse warnings is adequate because it follows ANSI recommendations and ensures the warning is readily visible to the consumer during replacement of the fuse.

103

Ibid.

Warning Statement Formatting:

An effective warning label first must be visible and noticeable, and it must capture and maintain consumers' attention. ANSI Z535.4 includes several design requirements that UL 2849-20 is lacking. To align with ANSI Z535.4 and improve the noticeability of the warning labels, the NPR proposes an additional marking requirement in new section 44.4 of UL 2849-20 and applicable for all warning statements in the standard. The new provision would require formatting modifications to the warning statements to, for example, be in contrasting color to the background; require the safety alert symbol and signal word to be in black letters on an orange background if the label is already using color processing; and specify heights and fonts of safety messaging.

Homemade Battery Warning:

Staff reviewed four incidents involving homemade batteries, three of which resulted in a fatality. In one incident (IDI 220908CAA1357), the victim and his landlord were manufacturing, repairing, charging, and selling lithium-ion batteries in the basement of their residence. In the second incident (IDI 220413CAA1350), the victim was reportedly manufacturing lithium-ion battery packs and repairing micromobility units in his apartment. A lithium-ion battery pack self-ignited, resulting in a fire and death of the victim. In the third incident (IDI 230213CAA1777), the victim and his pets died in a house fire that involved homemade batteries. In the fourth incident (IDI 200909CFE0001), the consumer “used parts of a camper battery to make his homemade bike battery . . . and built a system on the bicycle to use the battery for power.” According to the fire investigator and the consumer, the homemade battery was charged for several hours just before the fire occurred. No injury was reported.

CPSC assesses from the IDIs that a warning describing the consequences of using homemade batteries on micromobility products would help deter consumers from utilizing or manufacturing homemade batteries described in the reported incidents. Accordingly, the NPR proposes that eBikes include a warning against the use of homemade batteries. The proposed language stating “WARNING—Homemade batteries have caused fire and death. Never use a homemade battery with your [type of product]” describes hazard, the severe consequences of using homemade batteries (fire and death), and how to avoid the hazard.

Lifetime of the Battery/Charging Frequency:

CPSC is aware of several fire incidents involving the charging of a micromobility product battery after an extended period of disuse. In one incident (IDI 231114HCC3195), a consumer purchased an eBike and stored it in a garage for almost a year before charging it for the first time. The consumer later found soot and smoke damage in the garage and that the battery of the eBike had exploded. The consumer's neighbor was a fire commissioner and determined that the cause of the fire was the battery suffering thermal runaway, which caused the battery cells to rocket out.

Another incident (IDI 220428CFE0001) led to fatalities of two children involved an eScooter battery that had not been used for over three months. In another OMP incident (IDI 211130HFE0002), an inoperable eScooter caused a fire after the battery was plugged in for charging for approximately one year.

To address the risk of fire from infrequent charging of lithium-ion batteries, the NPR proposes to add a new section 44.6 building on UL 2849-20, requiring cautionary markings to include language informing consumers about the frequency with which to charge the lithium-ion battery and when to discard the battery. If the battery is not replaceable, the warning must be on the eBike including on the battery; if replaceable, the warning must be located on the battery. This language will alert consumers to safer battery charging behavior, particularly focusing on the amount of time since the last battery charge and whether the battery is still safe and functional for use.

Hazardous Voltage Warning:

UL 2849-20 does not contain a warning about hazardous voltage circuits, even though the standard defines the threshold for a circuit to be operating at a hazardous voltage. Therefore, the NPR proposes to add a new section 44.7 to UL 2849-20, which adds a warning statement for such products to inform consumers that hazardous voltage may be present, stating “Warning: Hazardous Voltage Circuits” or using an International Organization for Standardization (ISO) symbol for this hazard and that consumers should not open the enclosure.

Non-Replaceable Battery Warning:

Staff also observed that UL 2849-20 does not have a warning about batteries that are not user replaceable. eBikes with non-replaceable batteries must include warnings about a poten

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