# 1-Bromopropane (1-BP); Regulation Under the Toxic Substances Control Act (TSCA) > Briefs, arguments, decisions, and more. URL: https://www.frixlaw.com/law-library/documents/fr%3A2024-17204 ## Record - **Collection:** Federal Register - **Document type:** Proposed Rule - **Published:** August 8, 2024 - **Citation:** 89 FR 65066 ## Text ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 751 [EPA-HQ-OPPT-2020-0471; FRL-8156-01-OCSPP] RIN 2070-AK73 1-Bromopropane (1-BP); Regulation Under the Toxic Substances Control Act (TSCA) AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule. SUMMARY: The Environmental Protection Agency (EPA or Agency) is proposing to address the unreasonable risk of injury to human health presented by 1-bromopropane (1-BP) (CASRN 106-94-5), also known as n-propyl bromide, under its conditions of use as documented in EPA's August 2020 Risk Evaluation for 1-BP and the December 2022 Revised Risk Determination for 1-BP prepared under the Toxic Substances Control Act (TSCA). 1-BP is a widely used solvent in a variety of occupational and consumer applications, including vapor degreasing, aerosol degreasing, adhesives and sealants, and in insulation. EPA determined that 1-BP presents an unreasonable risk of injury to health due to the significant adverse health effects associated with exposure to 1-BP, including neurotoxicity, developmental toxicity from acute and chronic inhalation exposures and dermal exposures, and cancer from chronic inhalation exposures. TSCA requires that EPA address by rule any unreasonable risk of injury to health or the environment identified in a TSCA risk evaluation and apply requirements to the extent necessary so the chemical no longer presents unreasonable risk. To address the identified unreasonable risk, EPA is proposing requirements to, among other things, prevent consumer access to the chemical, restrict the industrial and commercial use of the chemical while also allowing for a reasonable transition period where an industrial and commercial use of the chemical is being prohibited, and protect workers from the unreasonable risk of 1-BP while on the job. DATES: Comments must be received on or before September 23, 2024. Under the Paperwork Reduction Act, comments on the information collection provisions are best assured of consideration if the Office of Management and Budget (OMB) receives a copy of your comments on or before September 9, 2024. ADDRESSES: Submit your comments, identified by docket identification (ID) number EPA-HQ-OPPT-2020-0471, through the Federal eRulemaking Portal at https://www.regulations.gov. Follow the online instructions for submitting comments. Do not submit electronically any information you consider to be Confidential Business Information (CBI) or other information whose disclosure is restricted by statute. Additional instructions on commenting or visiting the docket, along with more information about dockets generally, is available at https://www.epa.gov/dockets. FOR FURTHER INFORMATION CONTACT: For technical information: Bethany Masten, Existing Chemicals Risk Management Division, Office of Pollution Prevention and Toxics, Environmental Protection Agency, 1200 Pennsylvania Ave. NW, Washington, DC 20460-0001; telephone number (202) 564-8803; email address: 1BP_TSCA@epa.gov. For general information: The TSCA-Hotline, ABVI-Goodwill, 422 South Clinton Ave., Rochester, NY 14620; telephone number: (202) 554-1404; email address: TSCA-Hotline@epa.gov. SUPPLEMENTARY INFORMATION: I. Executive Summary A. Does this action apply to me? 1. General Applicability You may be potentially affected by the proposed action if you manufacture (defined under TSCA to include import), process, distribute in commerce, use, or dispose of 1-BP or products containing 1-BP. The following list of North American Industrial Classification System (NAICS) codes is not intended to be exhaustive, but rather provides a guide to help readers determine whether this document applies to them. Potentially affected entities include: • Crude Petroleum Extraction (NAICS code 211120). • All Other Specialty Trade Contractors (NAICS code 238990). • Broadwoven Fabric Mills (NAICS code 313210). • Nonwoven Fabric Mills (NAICS code 313230). • Textile and Fabric Finishing Mills (NAICS code 313310). • Fabric Coating Mills (NAICS code 313320). • Prefabricated Wood Building Manufacturing (NAICS code 321992). • Paper Bag and Coated and Treated Paper Manufacturing (NAICS code 322220). • Commercial Screen Printing (NAICS code 323113). • Petroleum Refineries (NAICS code 324110). • All Other Petroleum and Coal Products Manufacturing (NAICS code 324199). • Other Basic Inorganic Chemical Manufacturing (NAICS code 325180). • All Other Basic Organic Chemical Manufacturing (NAICS code 325199). • Paint and Coating Manufacturing (NAICS code 325510). • Adhesive Manufacturing (NAICS code 325520). • Soap and Other Detergent Manufacturing (NAICS code 325611). • Polish and Other Sanitation Good Manufacturing (NAICS code 325612). • Photographic Film, Paper, Plate, and Chemical Manufacturing (NAICS code 325992). • All Other Miscellaneous Chemical Product and Preparation Manufacturing (NAICS code 325998). • Polystyrene Foam Product Manufacturing (NAICS code 326140). • Urethane and Other Foam Product (except Polystyrene) Product Manufacturing (NAICS code 326150). • Tire Manufacturing (except Retreading) (NAICS code 326211). • Tire Retreading (NAICS code 326221). • Rubber and Plastics Hoses and Belting Manufacturing (NAICS code 326220). • All Other Rubber Product Manufacturing (NAICS code 326299). • Other Concrete Product Manufacturing (NAICS code 327390). • Gypsum Product Manufacturing (NAICS code 327420). • Cement Manufacturing (NAICS code 327310). • Iron and Steel Mills and Ferroalloy Manufacturing (NAICS code 331110). • Iron and Steel Pipe and Tube Manufacturing from Purchased Steel (NAICS code 331210). • Rolled Steel Shape Manufacturing (NAICS code 332221). • Steel Wire Drawing (NAICS code 331222). • Nonferrous Metal (except Aluminum) Smelting and Refining (NAICS code 331410). • Copper Rolling, Drawing, Extruding, and Alloying (NAICS code 331420). • Nonferrous Metal (except Copper and Aluminum) Rolling, Drawing, and Extruding (NAICS code 331491). • Secondary Smelting, Refining, and Alloying of Nonferrous Metal (except Copper and Aluminum) (NAICS code 331492). • Nonferrous Metal Die-Casting Foundries (NAICS code 331523). • Iron and Steel Forging (NAICS code 332111). • Nonferrous Forging (NAICS code 332112). • Custom Roll Forming (NAICS code 332114). • Powder Metallurgy Part Manufacturing (NAICS code 332117). • Metal Crown, Closure, and Other Metal Stamping (except Automotive) (NAICS code 332119). • Metal Kitchen Cookware, Utensil, Cutlery, and Flatware (except Precious) Manufacturing (NAICS code 332215). • Saw Blade and Handtool Manufacturing (NAICS code 332216). • Other Fabricated Wire Product Manufacturing (NAICS code 332618). • Metal Window and Door Manufacturing (NAICS code 332321). • Machine Shops (NAICS code 332710). • Precision Turned Product Manufacturing (NAICS code 332721). • Bolt, Nut, Screw, Rivet, and Washer Manufacturing (NAICS code 332722). • Industrial Valve Manufacturing (NAICS code 332911). • Metal Heat Treating (NAICS code 332811). • Metal Coating, Engraving (except Jewelry and Silverware), and Allied Services to Manufacturers (NAICS code 332812). • Electroplating, Plating, Polishing, Anodizing, and Coloring (NAICS code 332813). • Industrial Valve Manufacturing (NAICS code 332911). • Fluid Power Valve and Hose Fitting Manufacturing (NAICS code 332912). • Plumbing Fixture Fitting and Trim Manufacturing (NAICS code 332913). • Other Metal Valve and Pipe Fitting Manufacturing (NAICS code 332919). • Ball and Roller Bearing Manufacturing (NAICS code 332991). • Small Arms Ammunition Manufacturing (NAICS code 332992). • Ammunition (except Small Arms) Manufacturing (NAICS code 332993). • Small Arms, Ordnance, and Ordnance Accessories Manufacturing (NAICS code 332994). • Fabricated Pipe and Pipe Fitting Manufacturing (NAICS code 332996). • All Other Miscellaneous Fabricated Metal Product Manufacturing (NAICS code 332999). • Other Industrial Machinery Manufacturing (NAICS code 333249). • Air-Conditioning and Warm Air Heating Equipment and Commercial and Industrial Refrigeration Equipment Manufacturing (NAICS code 333415). • Special Die and Tool, Die Set, Jig, and Fixture Manufacturing (NAICS code 333514). • Cutting Tool and Machine Tool Accessory Manufacturing (NAICS code 333515). • Speed Changer, Industrial High-Speed Drive, and Gear Manufacturing (NAICS code 333612). • Air and Gas Compressor Manufacturing (NAICS code 333912). • Measuring, Dispensing, and Other Pumping Equipment Manufacturing (NAICS code 333914). • Elevator and Moving Stairway Manufacturing (NAICS code 333921). • Conveyor and Conveying Equipment Manufacturing (NAICS code 333922). • Overhead Traveling Crane, Hoist, and Monorail System Manufacturing (NAICS code 333923). • Industrial Process Furnace and Oven Manufacturing (NAICS code 333924). • Power-Driven Handtool Manufacturing (NAICS code 333991). • Welding and Soldering Equipment Manufacturing (NAICS code 333992). • Packaging Machinery Manufacturing (NAICS code 333993). • Industrial Process Furnace and Oven Manufacturing (NAICS code 333994). • Fluid Power Cylinder and Actuator Manufacturing (NAICS code 333995). • Fluid Power Pump and Motor Manufacturing (NAICS code 333996). • All Other Miscellaneous General Purpose Machinery Manufacturing (NAICS code 333998). • Audio and Video Equipment Manufacturing (NAICS code 334310). • Capacitor, Resistor, Coil, Transformer, and Other Inductor Manufacturing (NAICS code 334416). • Electronic Connector Manufacturing (NAICS code 334417). • Printed Circuit Assembly (Electronic Assembly) Manufacturing (NAICS code 334418). • Other Electronic Component Manufacturing (NAICS code 334419). • Search, Detection, Navigation, Guidance, Aeronautical, and Nautical System and Instrument Manufacturing (NAICS code 334511). • Automatic Environmental Control Manufacturing for Residential, Commercial, and Appliance Use (NAICS code 334512). • Instruments and Related Products Manufacturing for Measuring, Displaying, and Controlling Industrial Process Variables (NAICS code 334513). • Instrument Manufacturing for Measuring and Testing Electricity and Electrical Signals (NAICS code 334515). • Residential Electric Lighting Fixture Manufacturing (NAICS code 335131). • Commercial, Industrial, and Institutional Electric Lighting Fixture Manufacturing (NAICS code 335132). • Electric Lamp Bulb and Other Lighting Equipment Manufacturing (NAICS code 335139). • Power, Distribution, and Specialty Transformer Manufacturing (NAICS code 335311). • Motor and Generator Manufacturing (NAICS code 335312). • Switchgear and Switchboard Apparatus Manufacturing (NAICS code 335313). • Relay and Industrial Control Manufacturing (NAICS code 335314). • Fiber Optic Cable Manufacturing (NAICS code 335921). • Current-Carrying Wiring Device Manufacturing (NAICS code 335931). • Carbon and Graphite Product Manufacturing (NAICS code 335991). • Automobile and Light Duty Motor Vehicle Manufacturing (NAICS code 336110). • Heavy Duty Truck Manufacturing (NAICS code 336120). • Motor Vehicle Body Manufacturing (NAICS code 336211). • Truck Trailer Manufacturing (NAICS code 336212). • Motor Home Manufacturing (NAICS code 336213). • Travel Trailer and Camper Manufacturing (NAICS code 336214). • Motor Vehicle Gasoline Engine and Engine Parts Manufacturing (NAICS code 336310). • Motor Vehicle Electrical and Electronic Equipment Manufacturing (NAICS code 336320). • Motor Vehicle Steering and Suspension Components (except Spring) Manufacturing (NAICS code 336330). • Motor Vehicle Brake System Manufacturing (NAICS code 336340). • Motor Vehicle Transmission and Power Train Parts Manufacturing (NAICS code 336350). • Motor Vehicle Seating and Interior Trim Manufacturing (NAICS code 336360). • Motor Vehicle Metal Manufacturing (NAICS code 336370). • Other Motor Vehicle Parts Manufacturing (NAICS code 336390). • Aircraft Manufacturing (NAICS code 336411). • Aircraft Engine and Engine Parts Manufacturing (NAICS code 336412). • Other Aircraft Parts and Auxiliary Equipment Manufacturing (NAICS code 336413). • Guided Missile and Space Vehicle Manufacturing (NAICS code 336414). • Guided Missile and Space Vehicle Propulsion Unit and Propulsion Unit Parts Manufacturing (NAICS code 336415). • Other Guided Missile and Space Vehicle Parts and Auxiliary Equipment Manufacturing (NAICS code 336419). • Railroad Rolling Stock Manufacturing (NAICS code 336510). • Ship Building and Repairing (NAICS code 336611). • Wood Kitchen Cabinet and Countertop Manufacturing (NAICS code 337110). • Upholstered Household Furniture Manufacturing (NAICS code 337121). • Nonupholstered Wood Household Furniture Manufacturing (NAICS code 337122). • Institutional Furniture Manufacturing (NAICS code 337127). • Wood Office Furniture Manufacturing (NAICS code 337211). • Surgical Appliance and Supplies Manufacturing (NAICS code 339113). • Dental Equipment and Supplies Manufacturing (NAICS code 339114). • Jewelry and Silverware Manufacturing (NAICS code 339910). • Sporting and Athletic Goods Manufacturing (NAICS code 339920). • Gasket, Packing, and Sealing Device Manufacturing (NAICS code 339991). • Fastener, Button, Needle, and Pin Manufacturing (NAICS code 339993). • All Other Miscellaneous Manufacturing (NAICS code 339999). • Metal Service Centers and Other Metal Merchant Wholesalers (NAICS code 423510). • Industrial Machinery and Equipment Merchant Wholesalers (NAICS code 423830). • Drugs and Druggists' Sundries Merchant Wholesalers (NAICS code 424210). • Other Chemical and Allied Products Merchant Wholesalers (NAICS code 424690). • New Car Dealers (NAICS code 441110). • Used Car Dealers (NAICS code 441120). • Home Centers (NAICS code 444110). • Paint and Wallpaper Stores (NAICS code 444120). • Electronics and Appliance Retailers (NAICS code 449210). • Sporting Goods Stores (NAICS code 459110). • Scheduled Passenger Air Transportation (NAICS code 481111). • Other Support Activities for Air Transportation (NAICS code 488190). • Other Warehousing and Storage (NAICS code 493190). • Miscellaneous Intermediation (NAICS code 523910). • Portfolio Management and Investment Advice (NAICS code 523940). • Research and Development in the Physical, Engineering, and Life Sciences (except Nanotechnology and Biotechnology) (NAICS code 541715). • Research and Development in the Social Sciences and Humanities (NAICS code 541720). • Janitorial Services (NAICS code 561720). • Carpet and Upholstery Cleaning Services (NAICS code 561740). • Hazardous Waste Treatment and Disposal (NAICS code 562211). • Junior Colleges (NAICS code 611210). • Colleges, Universities, and Professional Schools (NAICS code 611230). • General Automotive Repair (NAICS code 811111). • Specialized Automotive Repair (NAICS code 811114). • Automotive Body, Paint, and Interior Repair and Maintenance (NAICS code 811121). • Automotive Glass Replacement Shops (NAICS code 811122). • Automotive Oil Change and Lubrication Shops (NAICS code 811191). • All Other Automotive Repair and Maintenance (NAICS code 811198). • Other Electronic and Precision Equipment Repair and Maintenance (NAICS code 811210). • Commercial and Industrial Machinery and Equipment (except Automotive and Electronic) Repair and Maintenance (NAICS code 811310). • Home and Garden Equipment Repair and Maintenance (NAICS code 811411). • Other Personal and Household Goods Repair and Maintenance (NAICS code 811490). • Coin-Operated Laundries and Drycleaners (NAICS code 812310). • Drycleaning and Laundry Services (except Coin-Operated) (NAICS code 812320). 2. Applicability to Importers and Exporters This action may also affect certain entities through pre-existing import certification and export notification rules under TSCA. Persons who import any chemical substance in bulk form, as part of a mixture, or as part of an article (if required by rule) are subject to TSCA section 13 (15 U.S.C. 2612) import certification requirements and the corresponding regulations at 19 CFR 12.118 through 12.127; see also 19 CFR 127.28. Those persons must certify that the shipment of the chemical substance complies with all applicable rules and orders under TSCA. The EPA policy in support of import certification appears at 40 CFR part 707, subpart B. In addition, any persons who export or intend to export a chemical substance that is the subject of this proposed rule are subject to the export notification provisions of TSCA section 12(b) (15 U.S.C. 2611(b)), and must comply with the export notification requirements in 40 CFR part 707, subpart D. If you have any questions regarding the applicability of this proposed action to a particular entity, consult the technical information contact listed under FOR FURTHER INFORMATION CONTACT . B. What is the Agency's authority for taking this action? Under TSCA section 6(a) (15 U.S.C. 2605(a)), if EPA determines through a TSCA section 6(b) risk evaluation that a chemical substance presents an unreasonable risk of injury to health or the environment, EPA must by rule apply one or more requirements listed in TSCA section 6(a) to the extent necessary so that the chemical substance or mixture no longer presents such risk. C. What action is the Agency taking? Pursuant to TSCA section 6(b), EPA determined that 1-BP presents an unreasonable risk of injury to health, without consideration of costs or other nonrisk factors, including an unreasonable risk to potentially exposed or susceptible subpopulations (PESS) and susceptible life stages identified as relevant to the 2020 Risk Evaluation for 1-BP by EPA, under the conditions of use (Refs. 1, 2). The term “conditions of use” is defined at TSCA section 3(4) (15 U.S.C. 2602(4)) to mean the circumstances under which a chemical substance is intended, known, or reasonably foreseen to be manufactured, processed, distributed in commerce, used, or disposed of. A detailed description of the conditions of use that EPA identified, evaluated and determined to contribute to EPA's determination that 1-BP presents an unreasonable risk is included in Unit III.B.1. EPA notes that all conditions of use of 1-BP (excluding the commercial and consumer use of 1-BP in insulation) are subject to this proposal. Accordingly, to address the unreasonable risk, EPA is proposing, under TSCA section 6(a), to: (i) Prohibit the manufacture (including import), processing, and distribution in commerce of 1-BP for all consumer uses (excluding insulation for building and construction materials), outlined in Unit IV.A.1.; (ii) Prohibit the manufacture (including import), processing and distribution in commerce of 1-BP for four industrial and commercial uses, outlined in Unit IV.A.1.; (iii) Require strict workplace controls, including a 1-BP Workplace Chemical Protection Program (WCPP), which would include requirements to meet an inhalation exposure concentration limit, for seven occupational conditions of use of 1-BP, outlined in Unit IV.A.2.; (iv) Require the use of prescriptive controls for six occupational conditions of use of 1-BP, outlined in Unit IV.A.3.; (v) Require purchasers to provide sellers with a self-certification, which would document the purchaser's commitment to comply with the 1-BP WCPP, for six occupational conditions of use of 1-BP, outlined in Unit IV.A.2.; and (vi) Establish recordkeeping and downstream notification requirements outlined in Unit IV.A.4. In addition, in each of the proposed rules under TSCA section 6(a), EPA is proposing to amend the general provisions of 40 CFR 751, subpart A, to define “ECEL,” and “exposure group,” so that these definitions may be commonly applied to this and other rules under TSCA section 6 that would be codified in 40 CFR part 751. EPA seeks public comment on all aspects of this proposed rule. D. Why is the Agency taking this action? Under TSCA section 6(a), “[i]f the Administrator determines in accordance with subsection (b)(4)(A) that the manufacture, processing, distribution in commerce, use or disposal of a chemical substance or mixture, or that any combination of such activities, presents an unreasonable risk of injury to health or the environment, the Administrator shall by rule . . . apply one or more of the [section 6(a)] requirements to such substance or mixture to the extent necessary so that the chemical substance or mixture no longer presents such risk.” 1-BP was the subject of a risk evaluation under TSCA section 6(b)(4)(A) that was issued in August 2020 (Ref. 1). In addition, EPA issued a revised unreasonable risk determination in December 2022 (Ref. 2), determining that 1-BP, as a whole chemical substance, presents an unreasonable risk of injury to health under the conditions of use. As a result, EPA is proposing to take action to the extent necessary so that 1-BP no longer presents such risk. The unreasonable risk is described in Unit III.B.2. and the conditions of use that contribute to the unreasonable risk for 1-BP are described in Unit III.B.1. 1-BP's hazards are well established. EPA's 2020 Risk Evaluation for 1-BP considered the hazards associated with exposure to 1-BP and determined that 1-BP presents an unreasonable risk of injury to health due to the significant adverse health effects associated with exposure to 1-BP. While some of the risks of adverse effects from 1-BP exposure may be acute and experienced for only a short duration, other health risks may be chronic and result in long-term impacts that are irreversible ( e.g., developmental toxicity, cancer). The most sensitive adverse health effect of 1-BP exposure is developmental toxicity. Other significant adverse health effects include reproductive toxicity, liver toxicity, kidney toxicity, neurotoxicity, other developmental toxicity, and cancer. For this proposed rulemaking, EPA has determined that protecting at the cancer endpoint would also address the risk for other acute or chronic non-cancer endpoints. This proposed rule, once final, would eliminate the unreasonable risk to human health from the TSCA conditions of use of 1-BP, as identified in the 2020 Risk Evaluation for 1-BP and the revised unreasonable risk determination for 1-BP in December 2022. This proposed rule, once final, is part of EPA's efforts to advance the Biden Cancer Moonshot policy, reducing exposure to carcinogens in the environment as part of a national effort to accelerate the rate of progress against cancer, reduce the cancer death rate, and improve the life experience of those living with and surviving cancer and their caregivers. EPA is not proposing a complete ban on 1-BP. This rule proposes to allow certain uses of 1-BP to continue provided that sufficient worker protections are in place to address the unreasonable risk for certain occupational conditions of use. For the conditions of use for which EPA is proposing strict workplace controls under a WCPP, EPA expects that many workplaces already have stringent controls in place that reduce exposures to 1-BP; for some workplaces, such as those using 1-BP in vapor degreasing, EPA understands that these existing controls may already reduce exposure enough to meet the inhalation exposure concentration limit proposed in this rulemaking (Ref. 1). Accordingly, EPA is proposing strict workplace controls to address the unreasonable risk and to allow continued use of 1-BP for several conditions of use, including processing for incorporation into formulation, mixture, or reaction products; use in vapor degreasing; use in cold cleaning; use in aerosol spray degreasers/cleaners; use in electronic and electronic products and metal products; use in asphalt extraction and laboratory chemicals; processing as a reactant/intermediate; and use in coatings for temperature indicators, which, in total, comprise an estimated 97% of the current production volume of 1-BP. EPA is proposing to prohibit certain conditions of use of 1-BP, including manufacture (including import), processing, and distribution in commerce of 1-BP for all consumer use, excluding the use of 1-BP in insulation; use in dry cleaning and spot cleaning, adhesives and sealants, liquid cleaners, automotive care products, anti-adhesive agents, functional fluids, and arts, crafts, and hobby materials, comprising an estimated 3% of the current production volume of 1-BP. Unit IV.A. describes EPA's proposed regulatory action and Unit IV.B. describes the alternative regulatory actions considered as required under TSCA section 6(c)(2)(A). The rationale for the proposed regulatory action and alternative regulatory actions, including what is feasible and appropriate for each condition of use, is described in Unit V., and the TSCA section 6 requirements considered in developing the regulatory actions are described in Unit III.B.3. E. What are the estimated incremental impacts of this action? EPA has prepared an Economic Analysis (EA) of the potential incremental impacts associated with this rulemaking that can be found in the rulemaking docket and is briefly summarized here (Ref. 3). The cost of the proposed rule is estimated to be $14.8 million annualized over 20 years at a 3% discount rate and $15.5 million annualized over 20 years at a 7% discount rate. These costs take compliance with implementation of a WCPP into consideration, which would include an existing chemical exposure limit (ECEL) of 0.05 ppm (0.25 mg/m3) for inhalation exposures as an 8-hour time-weighted average (TWA), applicable personal protective equipment (PPE) requirements, and reformulation costs of numerous products. The estimates discussed in the preamble reflect the central estimates for the number of sites and workers affected rather than the low- or high-end estimates. The sensitivity analysis in Chapter 11 presents the estimated costs, benefits, and net benefits for low, central, and high estimates of affected sites, workers, and occupational non-users (ONUs). The economic impact on users of 1-BP for vapor degreasing is unclear because some users may not be able to continue using their current equipment (open-top vapor degreasers). Based on engagement with industry, including public comments received on the draft risk evaluation and draft revised unreasonable risk determination for 1-BP, EPA expects workplaces engaged in vapor degreasing to have the ability to implement a WCPP that would include an ECEL, PPE requirements, and ancillary requirements. EPA estimates that complying with the WCPP would cost vapor degreasing users $13.8 million while prohibition would cost vapor degreasing users $174.8 million (3% discount rate annualized over 20 years). Vapor degreasing is used in several advanced manufacturing industries, including aerospace, automotive, energy, medical devices, and others (Ref. 3). The actions proposed in this rulemaking are expected to achieve health benefits for the American public, some of which can be monetized and others that, while tangible and significant, cannot be monetized. The monetized benefits of this rulemaking are approximately $27.2 million annualized over 20 years at a 3% discount rate and $12.9 million annualized over 20 years at a 7% discount rate. The monetized benefits include potential reductions in risk of colon and lung cancers. Non-monetized benefits include risk reduction of liver toxicity, kidney toxicity, reproductive toxicity, developmental toxicity, and neurotoxicity (peripheral neuropathy) (Ref. 3). As described in more detail in the Economic Analysis, the Agency analyzed the demographic characteristics of several populations that would be impacted by this rulemaking (Ref. 3). In general, workers in affected industries and regions, as well as residents of nearby communities, are similar to workers and residents nationwide. Data limitations prevent EPA from conducting a more comprehensive environmental justice (EJ) analysis that would identify the incremental impacts of the regulatory options and assess the extent to which they mitigate or exacerbate any disproportionate impacts in communities with EJ concerns. F. What should I consider as I prepare my comments for EPA? 1. Submitting CBI Do not submit CBI to EPA through https://www.regulations.gov or email. If you wish to include CBI in your comment, please follow the applicable instructions at https://www.epa.gov/dockets/commenting-epa-dockets#rules and clearly mark the part or all of the information that you claim to be CBI. In addition to one complete version of the comment that includes information claimed as CBI, a copy of the comment that does not contain the information claimed as CBI must be submitted for inclusion in the public docket. Information so marked will not be disclosed except in accordance with procedures set forth in 40 CFR part 2 and/or 40 CFR part 703, as appliable. 2. Tips for Preparing Your Comments When preparing and submitting your comments, see the commenting tips at https://www.epa.gov/dockets/commenting-epa-dockets. II. Background A. Overview of 1-BP This proposed rule applies to 1-BP (CASRN 106-94-5) and is specifically intended to address the unreasonable risk of injury to health EPA has identified in the 2020 Risk Evaluation for 1-BP and the 2022 revised unreasonable risk determination, as described in Unit III.B.2. 1-BP is a colorless, volatile liquid with a mildly sweet odor that is produced in and imported into the United States. 1-BP is manufactured, processed, distributed, used, and disposed of as part of many industrial, commercial, and consumer conditions of use. As outlined in further detail in Unit III.B.1., 1-BP is used as a solvent in cleaning and degreasing operations (including vapor degreasing, cold cleaning, and aerosol degreasing), spray adhesives, and dry cleaning. 1-BP is also used as a reactant in the manufacturing of other chemical substances. Consumer uses of 1-BP include aerosol degreasers, spot cleaners, and stain removers. 1-BP is also used in insulation for building and construction materials. According to data submitted for the 2016 submission period under EPA's Chemical Data Reporting (CDR) rule, the total aggregate annual production volume of 1-BP in the U.S. increased from 15.4 million pounds to 25.8 million pounds between 2012 and 2015 (Ref. 4). The total aggregate annual production volume ranged from 1 to 50 million pounds between 2016 and 2019 according to CDR (Ref. 5). B. Regulatory Actions Pertaining to 1-BP Because of its adverse health effects, 1-BP is subject to several Federal laws and regulations in the United States and is also subject to regulation by some States and other countries. A summary of EPA regulations pertaining to 1-BP, as well as other Federal, state, and international regulations, is in the docket and in Appendix A of the 2020 Risk Evaluation for 1-BP (Refs. 6, 1). EPA acknowledges that additional 1-BP regulatory steps occurred after 2020, including the addition of 1-BP as a Hazardous Air Pollutant (HAP) to the Clean Air Act list in January 2022, as discussed in Unit X.C.5. C. Consideration of Occupational Safety and Health Administration (OSHA) Occupational Health Standards in TSCA Risk Evaluations and TSCA Risk Management Actions Although EPA must consider and factor in, to the extent practicable, certain non-risk factors as part of TSCA section 6(a) rulemaking (see TSCA section 6(c)(2)), EPA must nonetheless still ensure that the selected regulatory requirements apply “to the extent necessary so that the chemical substance or mixture no longer presents [unreasonable] risk.” 15 U.S.C. 2605(a). This requirement to eliminate unreasonable risk is distinguishable from approaches mandated by some other laws, including the Occupational Safety and Health Act (OSH Act), which includes both significant risk and feasibility (technical and economic) considerations in the setting of standards. Congress intended for EPA to consider occupational risks from chemicals it evaluates under TSCA, among other potential exposures, as relevant and appropriate. As noted previously, section 6(b) of TSCA requires EPA to evaluate risks to PESS identified as relevant by the Administrator. TSCA section 3(12) defines the term “potentially exposed or susceptible subpopulation” as “a group of individuals within the general population identified by the Administrator who, due to either greater susceptibility or greater exposure, may be at greater risk than the general population of adverse health effects from exposure to a chemical substance or mixture, such as infants, children, pregnant women, workers, or the elderly.” The OSH Act similarly requires OSHA to evaluate risk specific to workers prior to promulgating new or revised standards and requires OSHA standards to substantially reduce significant risk to the extent feasible, even if workers are exposed over a full working lifetime. See 29 U.S.C. 655(b)(5); Indus. Union Dep't, AFL-CIO v. Am. Petroleum Inst., 448 U.S. 607, 642 (1980) (plurality opinion). Thus, the standards for chemical hazards that OSHA promulgates under the OSH Act share a broadly similar purpose with the standards that EPA promulgates under TSCA section 6(a). The control measures OSHA and EPA require to satisfy the objectives of their respective statutes may also, in many circumstances, overlap or coincide. However, as this section outlines, there are important differences between EPA's and OSHA's regulatory approaches and jurisdiction, and EPA considers these differences when deciding whether and how to account for OSHA requirements (Ref. 6) when evaluating and addressing potential unreasonable risk to workers so that compliance requirements are clearly explained to the regulated community. 1. OSHA Requirements OSHA's mission is to ensure that employees work in safe and healthful conditions. The OSH Act establishes requirements that each employer comply with the General Duty Clause of the Act (29 U.S.C. 654(a)), as well as with occupational safety and health standards issued under the Act. a. General Duty Clause of the OSH Act The General Duty Clause of the OSH Act requires employers to keep their workplaces free from recognized hazards that are causing or are likely to cause death or serious physical harm to employees. The General Duty Clause is cast in general terms, and does not establish specific requirements like exposure limits, PPE, or other specific protective measures that EPA could potentially consider when developing its risk evaluations or risk management requirements. OSHA, under limited circumstances, has cited the General Duty Clause for regulating exposure to chemicals. To prove a violation of the General Duty Clause, OSHA must prove employer or industry recognition of the hazard, the hazard was causing or likely to cause death or serious physical harm, and a feasible method to eliminate or materially reduce the hazard was available. In rare situations, OSHA has cited employers for violation of the General Duty Clause where exposures were below a chemical-specific permissible exposure limit (PEL), a TWA based on an employee's average airborne exposure in any 8-hour work shift of a 40-hour work week which shall not be exceeded (Ref. 7). In such situations, OSHA must demonstrate that the employer had actual knowledge that the PEL was inadequate to protect its employees from death or serious physical harm. Because of the heavy evidentiary burden on OSHA to establish violations of the General Duty Clause, it is not frequently used to cite employers for employee exposure to chemical hazards. b. OSHA Standards OSHA standards are issued pursuant to the OSH Act and are found in title 29 of the CFR. There are separate standards for general industry, laboratories, construction, maritime and agriculture sectors, and general standards applicable to a number of sectors ( e.g., OSHA's Respiratory Protection standard). OSHA has numerous standards that apply to employers who operate chemical manufacturing and processing facilities, as well as to downstream employers whose employees may be occupationally exposed to hazardous chemicals. OSHA sets legally enforceable limits on the airborne concentrations of hazardous chemicals, referred to as PELs, established for employers to protect their workers against the health effects of exposure to hazardous substances (29 CFR part 1910, subpart Z, part 1915, subpart Z, and part 1926, subparts D and Z). Under section 6(a) of the OSH Act, OSHA was permitted an initial 2-year window after the passage of the Act to adopt “any national consensus standard and any established Federal standard.” 29 U.S.C. 655(a). OSHA used this authority in 1971 to establish PELs that were adopted from Federal health standards originally set by the Department of Labor through the Walsh-Healy Act, in which approximately 400 occupational exposure limits (OELs) were selected based on the American Conference of Governmental Industrial Hygienists (ACGIH) 1968 list of Threshold Limit Values (TLVs). In addition, about 25 exposure limits recommended by the American Standards Association (now called the American National Standards Institute (ANSI) were adopted as PELs. Following the 2-year window provided under section 6(a) of the OSH Act for adoption of national consensus and existing Federal standards, OSHA has issued health standards following the requirements in section 6(b) of the Act. OSHA has established approximately 30 PELs under section 6(b)(5) as part of comprehensive substance-specific standards that include additional requirements for protective measures such as use of PPE, establishment of regulated areas, exposure assessment, hygiene facilities, medical surveillance, and training. These ancillary provisions in substance-specific OSHA standards further mitigate residual risk that could be present due to exposure at the PEL. OSHA has not established a PEL for 1-BP and for those it has, in many instances, scientific evidence has accumulated suggesting that the current limits of many PELs are not sufficiently protective. Unlike EPA's requirements under TSCA to address unreasonable risk, health standards issued under section 6(b)(5) of the OSH Act must reduce significant risk only to the extent that it is technologically and economically feasible. OSHA's legal requirement to demonstrate that its section 6(b)(5) standards are technologically and economically feasible at the time they are promulgated often precludes OSHA from imposing exposure control requirements sufficient to ensure that the chemical substance no longer presents a significant risk to workers. TSCA section 6(b) unreasonable risk determinations may account for unreasonable risk to more sensitive endpoints and working populations than OSHA's risk evaluations typically contemplate, and EPA is obligated to apply TSCA section 6(a) risk management requirements to the extent necessary so that the unreasonable risk is no longer presented. Because the requirements and application of TSCA and OSHA regulatory analyses differ, it is necessary for EPA to conduct risk evaluations and, where it finds unreasonable risk to workers, develop risk management requirements for chemical substances that OSHA also regulates, and it is expected that EPA's findings and requirements may sometimes diverge from OSHA's. However, it is also appropriate that EPA consider the chemical standards that OSHA has already developed to limit the compliance burden to employers by aligning management approaches required by the agencies, where alignment will adequately address unreasonable risk to workers. The following section discusses EPA's consideration of OSHA standards in its risk evaluation and management strategies under TSCA. 2. Consideration of OSHA Standards in TSCA Risk Evaluations When characterizing the risk during risk evaluation under TSCA, EPA believes it is appropriate to evaluate the levels of risk present in scenarios where no mitigation measures are assumed to be in place for the purpose of determining unreasonable risk (see Unit II.C.2.a.). (It should be noted that there are some cases where scenarios may reflect certain mitigation measures, such as in instances where exposure estimates are based on monitoring data at facilities that have existing engineering controls in place.) In addition, EPA believes it may be appropriate to also evaluate the levels of risk present in scenarios considering applicable OSHA requirements as well as scenarios considering industry or sector best practices for industrial hygiene that are clearly articulated to the Agency. EPA may evaluate risk under scenarios that consider industry or sector best practices for industrial hygiene that are clearly articulated to the Agency, when doing so serves to inform its risk management efforts. Characterizing risks using scenarios that reflect different levels of mitigation can help inform potential risk management actions by providing information that could be used during risk management to tailor risk mitigation appropriately to address any unreasonable risk identified (see Unit II.C.2.b. and Unit II.C.3.). a. Risk Characterization for Unreasonable Risk Determination When making unreasonable risk determinations as part of TSCA risk evaluations, EPA cannot assume as a general matter that all workers are always equipped with and appropriately using sufficient PPE, although it does not question the veracity of public comments received on the 2020 Risk Evaluation for 1-BP regarding the occupational safety practices often followed by industry respondents. When characterizing the risk to human health from occupational exposures during risk evaluation under TSCA, EPA believes it is appropriate to evaluate the levels of risk present in scenarios where PPE is not assumed to be used by workers. This approach of not assuming PPE use by workers considers the risk to PESS (workers and occupational non-users (ONUs)) who may not be covered by OSHA standards, such as self-employed individuals and public sector workers who are not covered by a State Plan. Mitigation scenarios included in the EPA risk evaluation in order to inform its risk management efforts ( e.g., scenarios considering use of PPE) likely represent current practice in many facilities where companies effectively address worker and bystander safety requirements. However, the Agency cannot assume that all facilities across all uses of the chemical substances will have adopted these practices for the purposes of making the TSCA risk determination. Therefore, EPA makes its determinations of unreasonable risk based on scenarios that do not assume compliance with OSHA standards, including any applicable exposure limits or requirements for use of respiratory protection or other PPE. Making unreasonable risk determinations based on such scenarios should not be viewed as an indication that EPA believes there are no occupational safety protections in place at any location, or that there is widespread noncompliance with applicable OSHA standards. Rather, it reflects EPA's recognition that unreasonable risk may exist: (1) for subpopulations of workers that may be highly exposed because they are not covered by OSHA standards, such as self-employed individuals and public sector workers who are not covered by an OSHA State Plan; (2) because EPA finds unreasonable risk for purposes of TSCA notwithstanding existing OSHA requirements. b. Risk Evaluation To Inform Risk Management Requirements In addition to the scenarios described previously, EPA risk evaluations may characterize the levels of risk present in scenarios considering applicable OSHA requirements ( e.g., chemical-specific PELs and/or chemical-specific health standards with PELs and additional ancillary provisions) as well as scenarios considering industry or sector best practices for industrial hygiene that are clearly articulated to the Agency to help inform risk management decisions. 3. Consideration of OSHA Standards in TSCA Risk Management Actions When undertaking risk management actions, EPA: (1) Develops occupational risk mitigation measures to address any unreasonable risk identified by EPA, striving for consistency with applicable OSHA requirements and industry best practices, including appropriate application of the hierarchy of controls (Ref. 8), when those measures would address an unreasonable risk; and (2) Ensures that EPA requirements apply to all potentially exposed workers in accordance with TSCA requirements. Consistent with TSCA section 9(d), EPA consults and coordinates TSCA activities with OSHA and other relevant Federal agencies for the purpose of achieving the maximum applicability of TSCA while avoiding the imposition of duplicative requirements. Informed by the mitigation scenarios and information gathered during the risk evaluation and risk management process, the Agency might propose rules that require risk management practices that may be already common practice in many or most facilities. Adopting clear, broadly applicable regulatory standards will foster compliance across all facilities (ensuring a level playing field) and assure protections for all affected workers, especially in cases where current OSHA standards may not apply to them or not be sufficient to address the unreasonable risk. 4. 1-BP and OSHA Requirements EPA incorporated the considerations described earlier in this unit in the 2020 Risk Evaluation for 1-BP, the December 2022 revised unreasonable risk determination for 1-BP, and this proposed risk management rulemaking. Specifically, in the TSCA 2020 Risk Evaluation for 1-BP, EPA presented risk estimates based on workers' exposures with and without respiratory protection. EPA determined that even when respirators with APF 50 are used by workers, most of the conditions of use evaluated presented an unreasonable risk. Additional consideration of OSHA standards in the revised unreasonable risk determination is discussed further in the Federal Register notice announcing that document (Ref. 9). In Units III.B.3. and V., EPA outlines the importance of considering the hierarchy of controls utilized by the industrial hygiene community (hereafter referred to as “hierarchy of controls”) when developing risk management actions in general, and specifically when determining if and how regulated entities may meet a risk-based exposure limit for 1-BP. The hierarchy of controls is a prioritization of exposure control strategies from most preferred to least preferred techniques. In order of precedence, they are: elimination of the hazard, substitution with a less hazardous substance, engineering controls, administrative controls such as training or exclusion zones with warning signs, and, finally, use of PPE (Ref. 8). Under the hierarchy of controls, the use of respirators (and all PPE) should only be considered after all other measures have been taken to reduce exposures. As discussed in Units IV.A. and V.A.1., EPA's risk management approach would not rely solely or primarily on the use of respirators to address unreasonable risk to workers; instead, EPA is proposing prohibitions for or affecting certain conditions of use, a WCPP for most occupational conditions of use, self-certification for certain occupational conditions of use, and prescriptive controls for certain occupational conditions of use. The WCPP would require consideration of the hierarchy of controls before use of respirators and other PPE. The WCPP is discussed in full in Units IV.A.2. and V.A.1.b. In accordance with the approach described earlier in Unit II.C.3., EPA intends for this regulation to be as consistent as possible with the existing OSHA standards, with additional requirements as necessary to address the unreasonable risk. One notable difference between the WCPP and the OSHA standards are the exposure limits. The WCPP would include an ECEL of 0.05 ppm as an 8-hour TWA to address unreasonable risks for chronic cancer and non-cancer and acute non- cancer inhalation endpoints. EPA recognizes that there is no OSHA PEL for 1-BP; however, OSHA and the National Institute for Occupational Safety and Health (NIOSH) issued a Hazard Alert in 2013, which indicates a recommended time-weighted average threshold limit value (TWA-TLV) of 10 ppm by the American Conference of Governmental Industrial Hygienists (Ref. 10). However, in 2011, ACGIH recommended 0.10 ppm as the TWA-TLV value for 1-BP and adopted this value in 2014. (Ref. 10). OSHA also released an Enforcement Policy for Respiratory Hazards Not Covered by OSHA Permissible Exposure Limits that explains OSHA requirements and the applicability of this policy pertaining to 1-BP exposure limits under certain conditions (Ref. 11). The TSCA ECEL value for 1-BP is a lower value than other existing OELs, discussed in Unit II.C.5., because many of those OELs are outdated, and they may not fully capture either the complete database of studies considered in the 2020 Risk Evaluation for 1-BP or more recent advances in modeling and scientific interpretation of toxicological data applied in the calculation of the 1-BP ECEL. EPA considers the 1-BP ECEL to represent the best available science under TSCA section 26(h) because it was derived from information in the 2020 Risk Evaluation for 1-BP, which was subject to peer review, and which is the result of a systematic review approach that investigated the reasonably available information in order to identify relevant adverse health effects. Additionally, by using the information from the 2020 Risk Evaluation for 1-BP, the ECEL incorporates advanced modeling and peer-reviewed methodologies, and accounts for exposures to potentially exposed or susceptible subpopulations, as required by TSCA. For 1-BP, the TSCA ECEL is an 8-hour occupational inhalation exposure limit based on cancer inhalation risks and takes into consideration the uncertainties identified in the 2020 Risk Evaluation for 1-BP (Ref. 12). The ECEL represents the concentration at which an adult human, including a member of a PESS, would be unlikely to suffer adverse effects if exposed for a working lifetime. EPA has determined as a matter of risk management policy that ensuring exposures remain at or below the ECEL will eliminate any unreasonable risk of injury to health from occupational inhalation exposures. In addition to the ECEL, as part of this rulemaking, EPA is proposing an ECEL action level. An ECEL action level, similar to other OEL frameworks, is typically a value lower than the ECEL value, that would trigger additional monitoring to ensure that workers are not exposed to concentrations above the ECEL. For 1-BP, the ECEL of 0.05 ppm is based on the cancer endpoints. As demonstrated in the ECEL memo, cancer from chronic inhalation exposures is the basis of the 1-BP ECEL (Ref. 12). As discussed in Units II.D., III.B., and VII.D., the TSCA ECEL represents the best available science at time of publication of the 2020 Risk Evaluation for 1-BP. 5. 1-BP and Other Occupational Exposure Limits EPA is aware of other OELs for 1-BP, including the California Division of Occupational Safety and Health (Cal/OSHA) PEL and the ACGIH TLV. The 2014 8-hour TWA TLV recommended by the ACGIH is 0.10 ppm. This TLV is based on the potential for neurotoxicity, liver toxicity, and reproductive/developmental toxicity. While a variety of studies covering numerous health effects are discussed in the report, the most relevant study cited (Ref. 13) reported “diminished vibration sensation and lower scores in memory and mood tests” in workers at measured occupational exposures as low as 0.34 ppm. The TLV appears to be semi-quantitative and not directly extrapolated from any individual point of departure. The August 2020 TSCA Risk Evaluation for 1-BP discussed the Ichihara results (Ref. 1, 13), however they were considered ambiguous due to 1-BP co-exposures that may have significantly contributed to the observed neurotoxicity. The TLV report also discusses the NTP 2011 cancer results that were the basis of the TSCA ECEL, however linear low-dose extrapolation was not performed in order to derive a lower TLV. The 2014 Cal/OSHA PEL is 5 ppm, higher than the ACGIH TLV, and has a skin notation, meaning that a worker's skin, eyes and mouth should be protected from any contact with 1-BP (Ref. 14). The Cal/OSHA PEL is based on reproductive and developmental toxicity (observed in animal studies) and technological feasibility assessments from industry (Ref. 14). D. Summary of EPA's Risk Evaluation Activities on 1-Bromopropane In December 2016, EPA selected 1-BP as one of the first 10 chemicals for risk evaluation under TSCA section 6 (Ref. 15). EPA published the scope of the 1-BP risk evaluation in June 2017 (82 FR 31592, July 7, 2017), and, after receiving public comments, published the problem formulation in June 2018 (83 FR 26998, June 11, 2018). In August 2019, EPA published a draft risk evaluation (84 FR 39830, August 12, 2019), and, after public comment and peer review by the Science Advisory Committee on Chemicals (SACC), EPA issued the 2020 Risk Evaluation for 1-BP in August 2020 in accordance with TSCA section 6(b) (85 FR 48687, August 12, 2020). EPA subsequently issued a draft revised TSCA unreasonable risk determination for 1-BP (87 FR 43265, July 20, 2022), and after public notice and receipt of comments, published a revised Unreasonable Risk Determination for 1-BP (87 FR 77603, December 2022). The 2020 Risk Evaluation for 1-BP and supplemental materials are in docket EPA-HQ-OPPT-2019-0235, with the December 2022 revised unreasonable risk determination and additional materials supporting the risk evaluation process are in docket EPA-HQ-OPPT-2016-0741, on https://www.regulations.gov. 1. 2020 Risk Evaluation In the 2020 Risk Evaluation for 1-BP, EPA evaluated risks associated with 25 conditions of use within the following categories: manufacture (including import), processing, distribution in commerce, industrial and commercial use, consumer use, and disposal. Descriptions of these conditions of use are in Unit III.B.1. The 2020 Risk Evaluation for 1-BP identified significant adverse health effects associated with exposure to 1-BP, including developmental toxicity from acute and chronic inhalation exposures and dermal exposures, and cancer from chronic inhalation exposures to 1-BP. A further discussion of the hazards of 1-BP is included in Unit III.B.2. 2. Revised Unreasonable Risk Determination EPA has been revisiting specific aspects of its first ten TSCA existing chemical risk evaluations, including the 2020 Risk Evaluation for 1-BP, to ensure that the risk evaluations upon which risk management decisions are made better align with TSCA's objective of protecting human health and the environment. For 1-BP, EPA revised the original unreasonable risk determination based on the 2020 Risk Evaluation for 1-BP and issued a final revised unreasonable risk determination on December 2022 (Ref. 2). EPA revised the risk determination for the 2020 Risk Evaluation for 1-BP pursuant to TSCA section 6(b) and consistent with Executive Order 13990, (“Protecting Public Health and the Environment and Restoring Science to Tackle the Climate Crisis”) and other Administration priorities (Refs. 16, 17, and 18). The revisions consisted of making the risk determination based on the whole-chemical substance instead of by individual conditions of use (which resulted in the revised risk determination superseding the prior “no unreasonable risk” determinations and withdrawing the associated TSCA section 6(i)(1) “no unreasonable risk” order); and clarifying that the risk determination does not reflect an assumption that all workers are always provided and appropriately wear PPE (Ref. 2). In determining whether 1-BP presents unreasonable risk under the conditions of use, EPA considered relevant risk-related factors, including, but not limited to: the effects of the chemical substance on health (including cancer and non-cancer risks) and human exposure to the substance under the conditions of use (including duration, magnitude, and frequency of exposure); the effects of the chemical substance on the environment and environmental exposure under the conditions of use; the population exposed (including any PESS); susceptible life stages; the severity of hazard (including the nature of the hazard, the irreversibility of the hazard); and uncertainties. EPA determined that 1-BP presents an unreasonable risk of injury to health. The contributions to the unreasonable risk determination are risks to workers and ONUs (workers who do not directly handle the chemical but perform work in an area where the chemical is present) due to occupational exposures to 1-BP ( i.e., during manufacture, processing, industrial and commercial uses, disposal); and to consumers and bystanders associated with consumer uses of 1-BP due to exposures from consumer use of 1-BP and products containing 1-BP. EPA did not identify risks of injury to the environment that contribute to the unreasonable risk determination for 1-BP. The 1-BP conditions of use that contribute to EPA's determination that the chemical substance poses unreasonable risk to health are listed in the unreasonable risk determination (Ref. 2) and also in Unit III.B.1., with descriptions to aid chemical manufacturers, processors, and users in determining how their particular use or activity would be addressed under the proposed regulatory provisions. While the 2020 Risk Evaluation for 1-BP estimated different risks for occupational non-users and workers, the benchmark (and thus the ECEL value) is the same for both populations. That is, while workers and occupational non-users may have different exposure patterns, the level of exposure such that risks are no longer unreasonable is the same for both workers and occupational non-users. Thus, for the purposes of risk management, the distinction between worker and occupational non-user is no longer relevant, and both are encompassed by the proposed definition of a potentially exposed person, as outlined in Unit IV.A.2.a. EPA notes that this proposed definition is intended to apply to occupational workplaces as part of implementation of the WCPP, and recognizes that other individuals or communities may be exposed to 1-BP as consumers, members of fenceline communities, or members of the general population. 3. Fenceline Screening Analysis The 2020 TSCA Risk Evaluation for 1-BP excluded the assessment of certain exposure pathways that were or could be regulated under another EPA-administered statute (see section 1.4.2 of the August 2020 Risk Evaluation for 1-BP (Refs. 1, 2). This resulted in the ambient air pathway for 1-BP exposure not being fully assessed for human health risk to the general population. The August 2020 Risk Evaluation for 1-BP did assess the water pathway based on fate and monitoring and modeling data, which determined there was no presence of 1-BP (Ref. 1). In June 2021, EPA made a policy announcement on the path forward for TSCA chemical risk evaluations, indicating that EPA would, among other things, examine whether the exclusion of certain exposure pathways from the risk evaluations could lead to a failure to identify and protect fenceline communities (Refs. 9; 15). EPA then conducted a screening analysis to identify whether there may be potential risks to people living near the fenceline of facilities releasing 1-BP. In order to determine whether there may be potential risk to the general population in proximity to a facility releasing 1-BP, EPA developed the TSCA Screening Level Approach for Assessing Ambient Air and Water Exposures to Fenceline Communities Version 1.0, which was presented to the SACC in March 2022, with a report issued by the SACC on May 18, 2022 (Ref. 19). This analysis is discussed in Unit VI.A. III. Regulatory Approach A. Background Under TSCA section 6(a), if the Administrator determines, through a TSCA section 6(b) risk evaluation that the manufacture (including import), processing, distribution in commerce, use, or disposal of a chemical substance or mixture, or any combination of such activities, presents an unreasonable risk of injury to health or the environment, EPA must by rule apply one or more of the following requirements to the extent necessary so that the chemical substance or mixture no longer presents such risk. • Prohibit or otherwise restrict the manufacturing, processing, or distribution in commerce of the substance or mixture, or limit the amount of such substance or mixture which may be manufactured, processed, or distributed in commerce (section 6(a)(1)). • Prohibit or otherwise restrict the manufacturing, processing, or distribution in commerce of the substance or mixture for a particular use or above a specific concentration for a particular use (section 6(a)(2)). • Limit the amount of the substance or mixture which may be manufactured, processed, or distributed in commerce for a particular use or above a specific concentration for a particular use specified (section 6(a)(2)). • Require clear and adequate minimum warning and instructions with respect to the substance or mixture's use, distribution in commerce, or disposal, or any combination of those activities, to be marked on or accompanying the substance or mixture (section 6(a)(3)). • Require manufacturers and processors of the substance or mixture to make and retain certain records or conduct certain monitoring or testing (section 6(a)(4)). • Prohibit or otherwise regulate any manner or method of commercial use of the substance or mixture (section 6(a)(5)). • Prohibit or otherwise regulate any manner or method of disposal of the substance or mixture, or any article containing such substance or mixture, by its manufacturer or processor or by any person who uses or disposes of it for commercial purposes (section 6(a)(6)). • Direct manufacturers or processors of the substance or mixture to give notice of the unreasonable risk determination to distributors, certain other persons, and the public, and to replace or repurchase the substance or mixture (section 6(a)(7)). As described in Unit III.B.3., EPA analyzed how the TSCA section 6(a) requirements could be applied to address the unreasonable risk found to be present in the 2020 Risk Evaluation for 1-BP and the final revised unreasonable risk determination, so that 1-BP no longer presents such unreasonable risk. EPA's proposed regulatory action and two alternative regulatory actions are described in Unit IV. EPA is requesting public comment on all elements of the proposed regulatory action and the alternative regulatory actions and is providing notice that based on consideration of comments and any new information submitted to EPA during the comment period on this proposed rule, EPA may in the final rule modify elements of the proposed regulatory action. The public should understand that public comments could result in changes to elements of the proposed and alternative regulatory actions when this rulemaking is finalized. For example, elements such as timelines for phase out could be lengthened or shortened, ECELs could be modified, or the WCPP could have conditions added or eliminated, or uses proposed to be prohibited could be allowed with a WCPP or uses proposed to be allowed with a WCPP could be prohibited. Under the authority of TSCA section 6(g), EPA may consider granting a time-limited exemption from a requirement of a TSCA section 6(a) rule for a specific condition of use if EPA finds that: (1) The specific condition of use is a critical or essential use for which no technically and economically feasible safer alternative is available, taking into consideration hazard and exposure; (2) Compliance with the requirement, as applied with respect to the specific condition of use would significantly disrupt the national economy, national security, or critical infrastructure; or (3) The specific condition of use, as compared to reasonably available alternatives, provides a substantial benefit to health, the environment, or public safety. At this time, EPA is not proposing to grant TSCA section 6(g) exemptions in this proposed rulemaking. TSCA section 6(c)(2)(A) requires EPA, in proposing and promulgating TSCA section 6(a) rules, to consider and include a statement addressing certain factors, including the costs and benefits and the cost effectiveness of the regulatory action and of the one or more primary alternative regulatory actions considered by the Administrator. A description of all TSCA section 6 requirements considered in developing this proposed regulatory action is in Unit III.B.3., and Unit V.B. includes more information regarding EPA's consideration of exemptions and alternatives. TSCA section 6(c)(2)(C) requires that in deciding whether to prohibit or restrict in a manner that substantially prevents a specific condition of use and in setting an appropriate transition period for such action, EPA consider, to the extent practicable, whether technically and economically feasible alternatives that benefit health or the environment will be reasonably available as substitutes when the proposed prohibition or restriction takes effect. Unit IV.B. includes more information regarding EPA's consideration of alternatives, and Unit VI. provides more information on EPA's considerations more broadly under TSCA section 6(c)(2). EPA carried out required consultations as described in this unit and also considered impacts on children's environmental health as part of its approach to developing this TSCA section 6 regulatory action. 1. Consultations EPA conducted consultations and outreach in developing this proposed regulatory action. The Agency held a federalism consultation from October 22, 2020, until January 23, 2021, as part of this rulemaking process and pursuant to Executive Order 13132 (64 FR 43255, August 10, 1999). This included a background presentation on September 9, 2020, and a consultation meeting on October 22, 2020. During the consultation, EPA met with State and local officials early in the process of developing the proposed action in order to receive meaningful and timely input into its development (Ref. 20). During the consultation, participants and EPA discussed preemption, EPA's authority under TSCA section 6 to regulate identified unreasonable risks, what activities would be potentially regulated in the proposed rule; and the relationship between TSCA and existing statutes—particularly the Clean Air Act (CAA) (Ref. 20). 1-BP is not manufactured (including imported), processed, distributed in commerce, or regulated by Tribal governments. However, EPA consulted with Tribal officials during the development of this proposed action (Ref. 21). The Agency held a Tribal consultation from October 7, 2020, to January 8, 2021, with meetings on November 12 and 17, 2020. Tribal officials were given the opportunity to meaningfully interact with EPA risk managers concerning the current status of risk management. During the consultation, EPA discussed risk management under TSCA section 6(a), findings from the 2020 Risk Evaluation for 1-BP, types of information that would be helpful to inform risk management, principles for transparency during the risk management process, and types of information EPA is seeking from tribes (Ref. 21). EPA received no written comments as part of this consultation. In addition to the formal consultations, EPA also conducted outreach to advocates of communities that might be subject to disproportionate risk from the exposures to 1-BP, such as low-income populations, and indigenous peoples. EPA's Environmental Justice (EJ) consultation occurred from November 4, 2020, through January 18, 2021. On November 16 and 19, 2020, EPA held public meetings as part of this consultation. These meetings were held pursuant to EPA policy to advance meaningful community engagement as part of the goal of environmental justice. During the consultations, participants and EPA discussed risk management under TSCA section 6(a), types of information that would be helpful to inform risk management, principles for transparency during the risk management process, and the relationship between TSCA and existing statutes, particularly the Clean Air Act. In general, commenters supported strong regulation of 1-BP to protect lower-income communities and workers. Commenters also supported strong outreach to affected communities, encouraged EPA to follow the NIOSH hierarchy of controls in regulating 1-BP, favored prohibitions, and noted the uncertainties associated with use of personal protective equipment ( e.g., in some cases, use of PPE did not provide adequate protection given the exposure scenario). (Ref. 22) As required by section 609(b) of the Regulatory Flexibility Act (RFA), 5 U.S.C. 601 et seq., EPA convened a Small Business Advocacy Review (SBAR) Panel to obtain advice and recommendations from small entity representatives (SERs) that potentially would be subject to this proposed rule's requirements (Ref. 23). EPA met with SERs before and during Panel proceedings, on November 5, 2020, and May 11, 2021. Panel recommendations are in Unit X.C. and in the Initial Regulatory Flexibility Analysis (IRFA) (Ref. 24); the Panel report is in the docket (Ref. 23). EPA requests comment on all elements of the IRFA, and, in particular, the flexibilities that EPA has identified following input from the SERs during the SBAR process. Additional requests for comment based on Panel recommendations are in Unit VIII. Units X.C., X.E., X.F., and X.J. provide more information regarding the consultations. 2. Other Stakeholder Engagement In addition to the formal consultations described in Unit X., EPA held a webinar on September 30, 2020, providing an overview of the TSCA risk management process and the risk evaluation findings for 1-BP. EPA also presented on the risk evaluation and risk management under TSCA for 1-BP at a Small Business Administration (SBA) Office of Advocacy Environmental roundtable on September 11, 2020. At both events EPA staff provided an overview of the TSCA risk management process and the findings in the 2020 Risk Evaluation for 1-BP (Ref. 25). Attendees of these meetings were given an opportunity to voice their concerns regarding the risk evaluation and risk management. Furthermore, EPA engaged in discussions with representatives from different industries, non-governmental organizations, technical experts and users of 1-BP. A list of external meetings held during the development of this proposed rule is in the docket (Ref. 26); meeting materials and summaries are also in the docket. The purpose of these discussions was to create awareness and educate stakeholders and regulated entities on the provisions for risk management required under TSCA section 6(a); explain the risk evaluation findings; obtain input from manufacturers, processors, distributors, users, academics, advisory councils, and members of the public health community about uses of 1-BP; identify workplace practices, engineering controls, administrative controls, PPE, and industrial hygiene plans currently in use or feasibly adoptable to reduce exposure to 1-BP under the conditions of use; understand the importance of 1-BP in the various uses subject to this proposed rule; compile knowledge about critical uses, substitute chemicals or alternative methods; identify various standards and performance specifications; and generate potential risk reduction strategies. EPA has met with, or otherwise communicated with, a variety of companies, trade associations and non-governmental organizations to discuss the topics outlined in this paragraph; a list of external meetings held during the development of this proposed rule is in the docket. (Ref. 26). 3. Children's Environmental Health EPA's Policy on Children's Health (Ref. 27) requires EPA to protect children from environmental exposures by consistently and explicitly considering early life exposures (from conception, infancy, early childhood and through adolescence until 21 years of age) and lifelong health in all human health decisions through identifying and integrating children's health data and information when conducting risk assessments. TSCA section 6(b)(4)(A) also requires EPA to conduct risk evaluations “to determine whether a chemical substance presents an unreasonable risk of injury to health or the environment . . . including an unreasonable risk to a potentially exposed or susceptible subpopulation identified as relevant to the risk evaluation by the Administrator, under the conditions of use.” Infants, children, and pregnant women are life stages that are listed as examples of subpopulations that may be considered relevant “potentially exposed or susceptible subpopulations” in the TSCA section 3(12) definition of that term. In addition, TSCA section 6(a) requires EPA to apply one or more risk management requirements under TSCA section 6(a) so that 1-BP no longer presents an unreasonable risk (including unreasonable risk to PESS). The 2020 Risk Evaluation for 1-BP considered impacts on both children and adults from occupational and consumer use from inhalation and dermal exposures, as applicable. For occupational use, the risk evaluation considered males (>16 years of age) and females of reproductive age (>16 years of age to less than 54 years of age) for both dermal and inhalation exposures. For consumer use, EPA evaluated dermal and inhalation exposures for children ages 11-15 and 16-20 years of age, and the evaluation of inhalation exposures to bystanders includes infants, toddlers, and older children. Several health effects of 1-BP exposure are relevant to early life stages, including developmental toxicity ( i.e. increases in post-implantation loss), and other adverse effects including reproductive toxicity and cancer. B. Regulatory Assessment of 1-BP 1. Description of Conditions of Use This unit describes the TSCA conditions of use that contribute to EPA's unreasonable risk determination for the chemical substance 1-BP. Condition of use descriptions were obtained from EPA sources such as CDR use codes, the 2020 Risk Evaluation for 1-BP and related documents, as well as the Organisation for Economic Co-operation and Development harmonized use codes and stakeholder engagements. For additional descriptions of the conditions of use, including process descriptions and worker activities considered in the risk evaluation, see the Problem Formulation of the 2020 Risk Evaluation for 1-BP, the 2020 Risk Evaluation for 1-BP, and supplemental files (Refs. 28, 1, 29). EPA acknowledges that some of the terms in this unit may be defined under other statutes, however the descriptions here are intended to provide clarity to the regulated entities who will implement the provisions of this rulemaking under TSCA section 6(a). a. Manufacturing (Including Import) i. Domestic Manufacture This condition of use refers to the making or producing of a chemical substance within the United States (including manufacturing for export), or the extraction of a component chemical substance from a previously existing chemical substance or a complex combination of substances. ii. Import This condition of use refers to the act of causing a chemical substance or mixture to arrive within the customs territory of the United States. b. Processing i. Processing as a Reactant/Intermediate This condition of use refers to processing 1-BP in chemical reactions for the manufacturing of another chemical substance or product. Through processing as a reactant or intermediate, 1-BP serves as a feedstock in the production of another chemical product via a chemical reaction in which 1-BP is completely consumed. For example, 1-BP is used as a reactant in the production of other organic and inorganic chemicals, pesticides, fertilizers, and other agricultural chemicals. ii. Processing: Incorporation Into a Formulation, Mixture, or Reaction Products This condition of use refers to when 1-BP is added to a product (or product mixture) prior to further distribution of the product. iii. Processing: Incorporation Into Articles This condition of use refers to when 1-BP becomes an integral component of an article distributed for industrial, commercial, or consumer use. An article refers to a manufactured item which: (1) Is formed to a specific shape or design during manufacture; (2) has end use function(s) dependent in whole or in part upon its shape or design during end use; and (3) has either no change of chemical composition during its end use or only those changes of composition which have no commercial purpose separate from that of the article, and that result from a chemical reaction that occurs upon end use of other chemical substances, mixtures, or articles, except that fluids are particles that are not considered articles regardless of shape or design. 40 CFR 704.3 iv. Processing by Repackaging This condition of use refers to the preparation of a chemical substance or mixture for distribution in commerce in a different form, state, or quantity. This includes transferring of 1-BP from a bulk container into smaller containers. v. Recycling This condition of use refers to processing waste streams of 1-BP at a third-party site for the purpose of recovering materials or otherwise preparing the waste for reuse instead of disposal. Waste solvents can be restored via solvent reclamation/recycling. The recovery process may involve an initial vapor recovery or mechanical separation step followed by distillation, purification, and final packaging. c. Industrial and Commercial Use i. Industrial and Commercial Use as Solvent for Open-Top Batch and In-Line Conveyorized Vapor Degreasing This condition of use refers to the industrial and commercial use of 1-BP as a solvent for cleaning and degreasing through the process of heating 1-BP to its volatilization point and using its vapors to remove dirt, oils, greases, and other surface contaminants from metal and other parts using batch open-top and in-line conveyorized vapor degreaser machines. ii. Industrial and Commercial Use as Solvent for Closed-Loop Batch Vapor Degreasing This condition of use refers to the industrial and commercial use of 1-BP as a solvent for cleaning and degreasing through the process of heating 1-BP to its volatilization point and using its vapors to remove dirt, oils, greases, and other surface contaminants from metal and other parts using batch closed-loop degreaser machines. iii. Industrial and Commercial Use as Solvent for Cold Cleaning This condition of use refers to the industrial and commercial use of 1-BP as a non-boiling solvent in cold cleaning machines, including simple spray sinks and dip tanks, to remove dirt, oils, greases, and other surface contaminants from metal and other parts. iv. Industrial and Commercial Use as Solvent for Aerosol Spray Degreaser/Cleaner This condition of use refers to the industrial and commercial use of 1-BP as a solvent in degreasing and cleaning products to remove dirt, grease, stains, spots, and foreign matter through a process that uses an aerosolized solvent spray, typically applied from a pressurized can, to remove residual contaminants from electronics, metals, and other fabricated materials. This description does not apply to use of 1-BP in products intended for automotive care, anti-adhesive agents for mold cleaning and release products, adhesive accelerants for arts, crafts, and hobby materials, or functional fluids, which are described in “Other industrial and commercial uses” in this unit, or dry cleaning solvents and stain removers, which are described in “Industrial and commercial use in dry cleaning solvents, spot cleaners and stain removers” in this unit. v. Industrial and Commercial Use in Adhesives and Sealants This condition of use refers to the industrial and commercial use of 1-BP as a solvent in spray adhesives and sealants for foam cushion manufacturing and fabrication ( e.g., the furniture industry). vi. Industrial and Commercial Use in Dry Cleaning Solvents, Spot Cleaners and Stain Removers This condition of use refers to the industrial and commercial use of 1-BP in products for spot cleaning and as a solvent in degreasing and cleaning applications to remove dirt, grease, stains, spots, and foreign matter from garments at dry cleaning facilities. This includes dry cleaning facilities using third generation (dry-to-dry, non-vented machines with refrigerated condensers), fourth generation (dry-to-dry, non-vented machines with both refrigerated condensers and carbon adsorbers as secondary vapor controls), or fifth generation (dry-to-dry, non-vented machines with secondary vapor controls, a monitor inside the machine drum, and an interlocking system to ensure the concentration is below approximately 300 ppm before the loading door can be opened) 1-BP dry cleaning machines. In addition to use as a solvent in dry cleaning equipment, 1-BP is found in products to spot clean garments to remove stains or spots before and after dry cleaning treatment. vii. Industrial and Commercial Use in Coin and Scissor Cleaner (Liquid, Spray, or Aerosol Cleaners) This condition of use refers to the industrial and commercial use of 1-BP in aerosol and non-aerosol product formulations, designed to clean collectible coins and scissors. viii. Commercial Use in Insulation This condition of use refers to the commercial use of 1-BP in insulation material in the form of rigid board insulation, which can be used for interior and exterior applications including walls, ceilings, roofs, foundations, basements, and crawl spaces in commercial and residential buildings. ix. Other Industrial and Commercial Uses This condition of use refers to the industrial and commercial uses of 1-BP in a variety of other aerosol and non-aerosol uses not already described previously in this unit. • Aerosol mold cleaning and release: This refers to the industrial and commercial use of 1-BP in aerosol mold cleaning and release products used to coat the molds for injection moldings, compression molding, blow molding, and extrusion applications. • Asphalt extraction: This refers to the industrial and commercial use of 1-BP for asphalt extraction in centrifuge extractors, vacuum extractors, and reflux extractors to separate asphalt from the aggregate and filler material to allow for determination of asphalt content. • Automotive care products: This condition of use also refers to the industrial and commercial use of 1-BP in aerosolized products, particularly engine degreasers and brake cleaners, to remove residual contaminants from fabricated parts. • General purpose degreaser: This refers to the industrial and commercial use of 1-BP in aerosolized and non-aerosolized products used in industrial settings, with usage varying widely by facility to clean and maintain equipment (primarily during plant shutdowns) and also used for heavy duty transportation maintenance ( e.g., maintaining buses, trains, trucks, etc.). • High voltage cable cleaner: This refers to the industrial and commercial use of 1-BP in both aerosolized and non-aerosolized cleaning products to clean the semi-conductive cores of high voltage cables when splicing and terminating cables. • Refrigerant flush: This refers to the industrial and commercial use of 1-BP in products used to clean refrigeration lines in various industries, and flush oxygen lines in hospitals and in the aerospace industry. • Temperature indicators: This refers to the industrial and commercial use of 1-BP in temperature-indicating fluids and coatings, which can be applied to fabrics, rubber, plastics, glass, and/or polished metals. • Other uses: This refers to the industrial and commercial use of 1-BP in a variety of other products such as an adhesive accelerant, a coating component for pipes and fixtures, functional fluids (closed/open systems), cutting oils, and as a laboratory chemical for research and development. d. Consumer Use i. Consumer Use as a Solvent in Aerosol Spray Degreasers/Cleaners This condition of use refers to the consumer use of 1-BP in aerosolized products to dissolve oils, greases, and similar materials from textiles, glassware, metal surfaces, and other articles. This includes the use of 1-BP in aerosolized products for cleaning or degreasing in electronic degreasers. ii. Consumer Use in Spot Cleaners or Stain Removers This condition of use refers to the consumer use of 1-BP for cleaning and furniture care in the form of spot cleaners or stain removers to remove dirt, grease, stains, and foreign matter from furniture or furnishings, or to cleanse, sanitize, or improve the appearance of surfaces. iii. Consumer Use in Liquid Cleaners (e.g., Coin and Scissor Cleaners) This condition of use refers to the consumer use of 1-BP in liquid cleaning products to dissolve oils, greases, and stains, or to cleanse, sanitize, or improve the appearance of surfaces. iv. Consumer Use in Liquid Spray/Aerosol Cleaners This condition of use refers to the consumer use of 1-BP in liquid and aerosolized products for cleaning and furniture care to remove dirt, grease, and stains, or to cleanse, scour, polish, protect, or improve the appearance of surfaces. v. Consumer Use in Arts, Crafts and Hobby Materials (Adhesive Accelerant) This condition of use refers to the consumer use of 1-BP in aerosolized products for arts, crafts, and hobby activities to accelerate the time it takes for the adhesive to dry. vi. Consumer Use in Automotive Care Products (Refrigerant Flush) This condition of use refers to the consumer use of 1-BP in liquid cleaning products to dissolve and flush out foreign materials from coils of an automobile AC coil. vii. Consumer Use in Anti-Adhesive Agents (Mold Cleaning and Release Products) This condition of use refers to the consumer use of 1-BP in products for mold cleaning and release. These products are used as anti-adhesive agents to prevent bonding between other substances by discouraging surface attachments. e. Disposal This condition of use refers to the process of disposing generated waste streams of 1-BP that are collected and transported to a third-party site for their final disposition, such as waste incineration or landfilling. f. Terminology in This Proposed Rule For purposes of this proposed rulemaking, “occupational conditions of use” refers to the TSCA conditions of use described in Units III.B.1.a., b., c., and e. Although EPA identified both industrial and commercial uses in the 2020 Risk Evaluation for 1-BP for purposes of distinguishing scenarios, the Agency clarified then and clarifies now that EPA interprets the authority Congress gave to the Agency to “regulat[e] any manner or method of commercial use” under TSCA section 6(a)(5) to reach both industrial and commercial uses. Additionally, in the 2020 Risk Evaluation for the chemical substance 1-BP, EPA identified and assessed all known, intended, and reasonably foreseen industrial, commercial, and consumer uses of 1-BP, and determined in the December 2022 final revised unreasonable risk determination that 1-BP as a whole chemical substance presents unreasonable risks to health and the environment. EPA determined that all industrial, commercial, and consumer uses of 1-BP evaluated in the 2020 Risk Evaluation for 1-BP contribute to the EPA determination that 1-BP presents unreasonable risk of injury to health, except for the use of 1-BP in insulation. As such, for purposes of this risk management rulemaking, “consumer use” refers to all known, intended, and reasonably foreseen consumer uses of 1-BP, except for the use of 1-BP in insulation. Likewise, for the purpose of this risk management rulemaking, “industrial and commercial use” refers to all industrial and commercial uses, including known, intended, or reasonably foreseen 1-BP industrial and commercial use, except for the use of 1-BP in insulation. EPA is not proposing to incorporate the descriptions of known, intended or reasonably foreseen uses in Unit III.B.1.a. through e. into the regulatory text as definitions because these uses represent the specific uses evaluated in the 2020 Risk Evaluation for 1-BP. This risk evaluation was used to inform EPA's determination that 1-BP presents unreasonable risk. EPA requests comment on whether EPA should promulgate definitions for those conditions of use evaluated in the 2020 Risk Evaluation for 1-BP that would not be prohibited, and, if so, whether the descriptions in this unit are consistent with the conditions of use evaluated in the 2020 Risk Evaluation for 1-BP and whether they provide a sufficient level of detail to improve the clarity and readability of the regulation if EPA were to promulgate a regulation that contains a list of the industrial and commercial conditions of use evaluated in the 2020 Risk Evaluation for 1-BP. EPA also requests comment on whether, rather than just excluding the consumer and commercial uses of 1-BP in insulation from the prohibitions and other requirements in this risk management rulemaking, EPA should more broadly exclude the use of articles under TSCA section 6(c)(2)(E), which would also exclude the use of 1-BP in articles that were not specifically evaluated in the 2020 Risk Evaluation for 1-BP, and if so, whether and how to define “article” for the purposes of this rulemaking. EPA further notes that this proposed rule does not apply to any substance excluded from the definition of “chemical substance” under TSCA 3(2)(B)(ii) through (vi). Those exclusions include, but are not limited to, any pesticide (as defined by the Federal Insecticide, Fungicide, and Rodenticide Act) when manufactured, processed, or distributed in commerce for use as a pesticide; and any food, food additive, drug, cosmetic, or device, as defined in section 201 of the Federal Food, Drug, and Cosmetic Act (FFDCA), when manufactured, processed, or distributed in commerce for use as a food, food additive, drug, cosmetic or device. 2. Description of Unreasonable Risk Under the Conditions of Use EPA has determined that 1-BP presents an unreasonable risk of injury to human health under the conditions of use based on acute and chronic non-cancer risks and chronic cancer risks (Ref. 2). As described in the TSCA section 6(b) 2020 Risk Evaluation for 1-BP, EPA identified non-cancer adverse effects from acute and chronic inhalation and dermal exposures to 1-BP, and cancer from chronic inhalation and dermal exposures to 1-BP (Ref. 1). For this proposed rulemaking, EPA has determined that protecting people from 1-BP-related cancer would also protect people from unreasonable risks for other 1-BP-related acute or chronic adverse health effects. EPA identified non-cancer adverse effects from acute inhalation and dermal exposures and non-cancer adverse effects from chronic inhalation and dermal exposures for all conditions of use (Ref. 1). Additional risks associated with other adverse effects ( e.g., developmental toxicity, reproductive toxicity, liver toxicity, kidney toxicity, neurotoxicity) were identified for acute and chronic exposures. EPA also concluded, based on EPA's Guidelines for Carcinogen Risk Assessment (Ref. 30), that 1-BP is considered to be carcinogenic to workers and ONUs by all routes of exposure and calculated cancer risks from chronic inhalation and dermal exposures. Unit VI.A. summarizes the health effects and the magnitude of the exposures (Ref. 1). To make the unreasonable risk determination for 1-BP, EPA evaluated exposures to workers, ONUs, consumer users, and bystanders to consumer use, using reasonably available monitoring and modeling data for inhalation and dermal exposures (Ref. 2). The August 2020 Risk Evaluation for 1-BP did assess the water pathway based on environmental fate characteristics and monitoring and modeling data. Based on this analysis, EPA determined that 1-BP would be unlikely to be present in surface water (Ref. 1). EPA conducted a screening level analysis to determine whether there may be potential risks from the ambient air pathway to fenceline communities. A discussion of EPA's analysis and the expected effects of this rulemaking on fenceline communities and the ongoing revisions of National Emission Standards for Hazardous Air Pollutants (NESHAPs) under the CAA is in Unit VI.A. For the 2020 Risk Evaluation for 1-BP, EPA considered PESS. EPA identified the following groups as PESS: workers, ONUs, consumers, bystanders, and those with certain pre-existing health conditions, higher body fat content, or particular genetic polymorphisms (Ref. 1). Furthermore, the developing fetus and (by extension) women of childbearing age were identified as susceptible life stages (Ref. 1). All PESS and susceptible life stages are included in the quantitative and qualitative analyses described in the risk evaluation and were considered in the determination of unreasonable risk for 1-BP. As discussed in Units II.D. and VI.A., the 2020 Risk Evaluation for 1-BP did not fully assess the ambient air exposure pathways to the general population in the published risk evaluation; this may have caused some risks to be unaccounted for in the risk evaluation and in EPA's risk determination. EPA considers people in communities in proximity to facilities using 1-BP who are exposed to 1-BP through the ambient air pathway to constitute a subset of the general population and categorizes them as fenceline communities; they may also be considered PESS. See Unit VI.A. for further discussion on assessing and protecting against risk to fenceline communities. 3. Description of TSCA Section 6 Requirements for Risk Management EPA examined the TSCA section 6(a) requirements (listed in Unit III.A.) to identify which ones have the potential to eliminate the unreasonable risk for 1-BP. This unit summarizes the TSCA section 6 considerations for issuing regulations under TSCA section 6(a). Unit V. outlines how EPA applied these considerations specifically to managing the unreasonable risk from 1-BP. As required, EPA developed a proposed regulatory action and one or more primary alternative regulatory actions, which are described in Units IV.A. and IV.B., respectively. To identify and select a regulatory action, EPA considered the two routes of exposure driving the unreasonable risk, inhalation and dermal, and the exposed populations. For occupational conditions of use (see Unit III.B.1.f.), EPA considered how it could directly regulate manufacturing (including import), processing, distribution in commerce, industrial and commercial use, or disposal to address the unreasonable risk. EPA does not have direct authority to regulate consumer use. Therefore, EPA considered how it could exercise its authority under TSCA to regulate the manufacturing (including import), processing, and/or distribution in commerce of 1-BP at different points in the supply chain to eliminate exposures or restrict the availability of 1-BP and 1-BP-containing products for consumer use in order to address the unreasonable risk. As required by TSCA Section 6(c)(2), EPA considered several factors, in addition to identified unreasonable risk, when selecting among possible TSCA section 6(a) requirements. To the extent practicable, EPA factored into its decisions: (1) the effects of 1-BP on health and the environment, (2) the magnitude of exposure to 1-BP of human beings and the environment, (3) the benefits of 1-BP for various uses, and (4) the reasonably ascertainable economic consequences of the rule. In evaluating the reasonably ascertainable economic consequences of the proposed rule, EPA considered (1) the likely effect of the proposed rule on the national economy, small business, technological innovation, the environment, and public health, (2) the costs and benefits of the proposed regulatory action and one or more primary alternative regulatory actions considered, and (3) the cost effectiveness of the proposed regulatory action and of the one or more primary alternative regulatory actions considered. See Unit VI. for further discussion related to TSCA section 6(c)(2)(A) considerations, including the statement of effects of the proposed rule with respect to these considerations. EPA also considered the regulatory authority under TSCA and other statutes such as the OSH Act, the Consumer Product Safety Act (CPSA), and other EPA-administered statutes to examine (1) whether there are opportunities for all or part of risk management action on 1-BP to be addressed under other statutes, such that a referral may be warranted under TSCA sections 9(a) or 9(b); or (2) whether TSCA section 6(a) regulation could include alignment of requirements and definitions in and under existing statutes to minimize confusion to the regulated entities and the general public. In addition, EPA followed other TSCA requirements such as considering the availability of alternatives when contemplating prohibition or a substantial restriction (TSCA section 6(c)(2)(C), as outlined in Unit V.B.), and setting proposed compliance dates in accordance with the requirements in TSCA section 6(d)(1) (described in the proposed and alternative regulatory actions in Unit IV.). To the extent information was reasonably available, when selecting regulatory actions, EPA considered pollution prevention and the hierarchy of controls adopted by OSHA and NIOSH, with the goal of identifying risk management control methods that are permanent, feasible, and effective. EPA also considered how to address the unreasonable risk while providing flexibility to the regulated entities where appropriate. EPA considered the information presented in the 2020 Risk Evaluation for 1-BP, as well as additional input from stakeholders (as described in Unit III.A.), and anticipated compliance strategies from regulated entities. Taken together, these considerations led EPA to the proposed regulatory action and primary alternative regulatory actions described in Unit IV. Additional details related to how the requirements in this unit were incorporated into development of those actions are in Unit V. As demonstrated by the number of distinct programs addressed in this rulemaking and the structure of this proposed rule in addressing them independently, EPA generally intends the rule's provisions to be severable from each other. EPA expects to provide additional detail on severability in the final rule once the Agency has considered public comments and finalized the regulatory language. IV. Proposed and Alternative Regulatory Actions This unit describes the proposed regulatory action by EPA so that 1-BP will no longer present an unreasonable risk of injury to health. In addition, as indicated by TSCA section 6(c)(2)(A), EPA must consider the costs and benefits and the cost-effectiveness of the proposed regulatory action and one or more primary alternative regulatory actions. In the case of 1-BP, the proposed regulatory action is described in Unit IV.A. and the two alternative regulatory actions considered are described in Unit IV.B. An overview of the proposed regulatory action and two alternative regulatory actions for each condition of use is in Unit IV.C. The rationale for the proposed and alternative regulatory actions and associated compliance timeframes are discussed in this unit and in more detail in Unit V.A. A. Proposed Regulatory Action EPA is proposing under TSCA section 6(a) to: (1) prohibit the manufacture (including import), processing, and distribution in commerce of 1-BP for all consumer uses, excluding the use of 1-BP in insulation, outlined in Unit IV.A.1.b.; (2) prohibit the industrial and commercial use of 1-BP for four occupational uses, and the manufacture (including import), processing, and distribution in commerce of 1-BP for those uses, outlined in Unit IV.A.1.a.; (3) require strict workplace controls, including a 1-BP WCPP, which would include requirements to meet an inhalation exposure concentration limit and use of gloves for seven occupational conditions of use, outlined in Unit IV.A.2.; (4) require self-certification, which would document the purchaser's commitment to comply with the 1-BP WCPP, for six occupational conditions of use, outlined in Unit IV.A.1.4.; (5) require the use of prescriptive controls for six occupational conditions of use, outlined in Unit IV.A.1.3.; and (6) establish recordkeeping and downstream notification requirements, outlined in Unit IV.A.5. Pursuant to TSCA section 12(a)(2), this proposed rule would apply to 1-BP even if being manufactured, processed, or distributed in commerce solely for export from the United States because EPA has determined that 1-BP presents an unreasonable risk to health within the United States or to the environment of the United States. EPA notes that some uses identified for prohibitions, the WCPP, or self-certification were identified within larger conditions of use in the 2020 Risk Evaluation for 1-BP. The regulatory action proposed for each use is described in this unit, and the rationale is provided in Unit V. 1. Prohibitions of Manufacturing, Processing, Distribution in Commerce, and Use a. Prohibition of Certain Industrial and Commercial Uses and Manufacturing, Processing, and Distribution of 1-BP for Those Uses EPA is proposing to prohibit the manufacturing, processing, distribution in commerce, and use of 1-BP for industrial and commercial uses of 1-BP except for those uses which would continue under the WCPP, self-certification, and/or prescriptive controls. The proposed prohibitions under TSCA would not apply to any use of 1-BP that is excluded from TSCA's definition of “chemical substance” under TSCA section 3(2)(B)(ii)(vi). This proposed prohibition would include a prohibition on the manufacturing (including import), processing, distribution in commerce, and use of 1-BP for the following industrial and commercial uses: • In adhesives and sealants; • In dry cleaning solvents, spot cleaners and stain removers; • In coin and scissor cleaner (liquid, spray, or aerosol cleaners); and • In other uses in arts, crafts, hobby materials (adhesive accelerant); automotive care products (engine degreaser, brake cleaner, refrigerant flush); anti-adhesive agents (mold cleaning and release product); functional fluids (closed/open-systems)—refrigerant/cutting oils. As discussed in Units III.B.3. and V.A., based on consideration of alternatives under TSCA section 6(c)(2)(C), uncertainty relative to the feasibility of exposure reduction to sufficiently address the unreasonable risk across the broad ranges of work environments and activities, and the irreversible health effects associated with 1-BP exposures, EPA has determined that prohibition is the best way to address the unreasonable risks from 1-BP contributed by the conditions of use identified in this unit. As noted in Unit III.B.1.f., this proposal does not apply to any substance excluded from the definition of “chemical substance” under TSCA section 3(2)(B)(ii) through (vi). EPA is proposing to stagger the compliance dates for the proposed prohibitions described in this unit, such that the requirements would come into effect in 6 months for manufacturers, 9 months for processors, 12 months for distributing to retailers, 15 months for all distributors (including retailers), and 18 months for industrial and commercial users after the publication date of the final rule. When proposing these compliance dates as required under TSCA section 6(d), EPA considered the irreversible health effects and risks associated with 1-BP exposure. EPA has no reasonably available information indicating that the proposed compliance dates are not practicable for the activities that would be prohibited, or that additional time would be needed for products to clear the channels of trade. For 1-BP, for the conditions of use EPA is proposing to prohibit, the Agency believes either 1-BP may no longer be used, or regulated entities would be able to meet the proposed regulatory compliance timeframes, due to availability of alternatives. EPA recognizes that for other proposed regulations under TSCA section 6, including methylene chloride (88 FR 28284, May 3, 2023 (FRL-8155-02-OCSPP), perchloroethylene (88 FR 39652, June 16, 2023) (FRL-8329-02-OCSPP), and carbon tetrachloride (88 FR 49180, July 28, 2023) (FRL-8206-01-OCSPP), public comments have provided information in support of longer compliance timeframes. Similarly, for 1-BP, EPA requests comment on whether additional time is needed, for example, for products to clear the channels of trade, or for implementing the use of substitutes; comments should include documentation such as the specific use of the chemical throughout the supply chain; concrete steps taken to identify, test, and qualify substitutes for those uses (including details on the substitutes tested and the specific certifications that would require updating); and estimates of the time required to identify, test, and qualify substitutes with supporting documentation. EPA also requests comment on whether there are other considerations that should apply. EPA may finalize shorter or significantly longer compliance timeframes based on consideration of public comments. EPA would also like comment on whether it should consider a de minimis level of 1-BP in formulations for certain continuing industrial and commercial uses to account for impurities ( e.g., 0.1% or 0.5%) when finalizing these prohibitions, and, if so, what level should be considered de minimis . b. Prohibition of Manufacturing, Processing and Distribution in Commerce of 1-BP for Consumer Use In the 2020 Risk Evaluation for 1-BP, EPA evaluated consumer uses of 1-BP: • As a solvent in aerosol spray degreasers/cleaners; • In spot cleaners and stain removers; • In liquid coin cleaners ( e.g., coin and scissor cleaners); • In liquid spray/aerosol cleaners; • In arts, crafts, hobby materials (adhesive accelerant); • In automotive care products (refrigerant flush); • In anti-adhesive agents (mold cleaning and release products); and • In building/construction materials in insulation. The consumer uses evaluated in the 2020 Risk Evaluation for 1-BP constitute all known, intended, and reasonably foreseen consumer uses of 1-BP. EPA determined that all of these consumer uses, except for the use of 1-BP in insulation, contribute to unreasonable risk of injury to health. As such, for purposes of this risk management rulemaking, “consumer use” refers to all consumer uses including known, intended, and reasonably foreseen consumer uses for 1-BP. EPA is proposing to prohibit the manufacturing, processing, and distribution in commerce of 1-BP for consumer use, except for the consumer use of 1-BP in insulation. As discussed in Units III.B.3. and V.A., based on consideration of the severity of the hazards of 1-BP in conjunction with the limited options available to adequately address the identified unreasonable risk to consumers and bystanders under TSCA section 6(a), EPA is proposing to address the unreasonable risk from consumer use by prohibiting the manufacturing (including import), processing, and distribution in commerce of 1-BP for consumer use, in order to remove 1-BP and products containing 1-BP from the market, thereby effectively eliminating instances of consumer use that contribute to the unreasonable risk of injury to health. Additionally, EPA is proposing to prohibit retailers from distributing in commerce 1-BP, including any 1-BP-containing products except insulation products, in order to prevent products intended for industrial and commercial use from being purchased by consumers. A retailer is any person or business entity that distributes or makes available chemical substances or products containing chemical substances to consumers, including through e-commerce internet sales or distribution. If a person or business entity distributes or makes available any product to at least one consumer, then it is considered a retailer (as EPA proposes to define that term in 40 CFR 751.5). For a distributor not to be considered a retailer, the distributor must distribute or make available chemical substances solely to commercial or industrial end-users or businesses. Prohibiting manufacturers (including importers), processors, and distributors from distributing 1-BP, or any products except insulation containing 1-BP, to retailers would prevent retailers from making these products available to consumers, which would help address that part of the unreasonable risk associated with consumer use of 1-BP. EPA is requesting comment on commercial distribution channels or systems that would allow for distribution to commercial users while preventing retailers from making these products available to consumers, or feasible distribution channels for commercial users that have been developed in analogous situations, including information on whether there are market barriers to such systems. EPA is proposing that the prohibitions of manufacturing, processing, and distribution in commerce of 1-BP for consumer use described in this unit would become effective in 6 months for manufacturers, 9 months for processers, 12 months for distributing to retailers, and 15 months for all other distributors (including retailers) after the publication date of the final rule in the Federal Register . EPA considered the irreversible health effects and risks associated with 1-BP when proposing compliance dates. EPA has no reasonably available information indicating these proposed compliance dates are not practicable for the activities that would be prohibited, or that additional time is needed for products to clear the channels of trade. However, EPA requests comment on whether additional time is needed, for example, for products to clear the channels of trade. EPA may finalize shorter or significantly longer compliance timeframes based on public comment. 2. Workplace Chemical Protection Program (WCPP) a. Overview As described in Unit III.B.3., under TSCA section 6(a), EPA is required to issue a regulation applying one or more of the TSCA section 6(a) requirements to the extent necessary so that the unreasonable risk of injury to health or the environment from a chemical substance is no longer presented. The TSCA section 6(a) requirements provide EPA the authority to limit or restrict a number of activities, alone or in combination, including the manufacture, processing, distribution in commerce, commercial use, and disposal of the chemical substance. Given this authority, EPA may find it appropriate in certain circumstances to propose requirements under a WCPP for certain occupational ( i.e., manufacturing, processing, industrial and commercial use, and disposal) conditions of use. A WCPP for 1-BP would encompass the inhalation exposure limit and action level, the associated implementation requirements, and may include other components, such as respiratory protection or dermal protection, as described in this unit to ensure that the chemical substance no longer presents unreasonable risk. Under a WCPP, owners or operators would have some flexibility, within the parameters outlined in this unit, regarding how they prevent exceedances of the identified EPA exposure limit thresholds. In the case of 1-BP, meeting the EPA exposure limits, in tandem with other requirements as listed in this proposed rule, for certain occupational conditions of use would address unreasonable risk to potentially exposed persons from inhalation and dermal exposure. EPA uses the term “potentially exposed person” in this unit and in the regulatory text to include workers, occupational non-users, employees, independent contractors, employers, and all other persons in the work area where 1-BP is present and who may be exposed to 1-BP under the conditions of use for which a WCPP would apply. One important reason to define a potentially exposed person for the purposes of a WCPP as any person who may be exposed in the workplace is to emphasize the broad scope of exposures which must be categorized when implementing a WCPP. EPA notes that this definition is intended to apply only in the context of risk management, and specifically in the context of a WCPP ( e.g., workers directly using the chemical, workers in the vicinity of the use, students in a laboratory setting). The term is not intended as a replacement for the term Potentially Exposed or Susceptible Subpopulation as defined by TSCA section 3(12). EPA additionally recognizes that other individuals or communities may be exposed to 1-BP as consumers, members of fenceline communities, or members of the general population, which is separate and apart from those potentially exposed for the purposes of the regulatory requirements of the WCPP. In those instances, where regulatory requirements address exposures unrelated to a WCPP EPA would use distinct terminology to refer to those other populations. EPA's intention is to require a comprehensive WCPP that would address the unreasonable risk from 1-BP to potentially exposed persons directly handling the chemical or in the area where the chemical is being used. Similarly, the 2020 risk evaluation for 1-BP did not distinguish between employers, contractors, or other legal entities or businesses that manufacture, process, distribute in commerce, use, or dispose of 1-BP. EPA uses the term “owner or operator” to describe the entity responsible for implementing the WCPP for workplaces where an applicable condition of use of 1-BP is occurring. The term includes any person who owns, leases, operates, controls, or supervises such a workplace. An ECEL is a risk-based inhalation exposure threshold. The ECEL would be accompanied by monitoring, training, recordkeeping and other requirements to help ensure that the threshold is not exceeded. With an ECEL, regulated entities have some flexibility, within certain parameters outlined in this unit, for preventing exceedances of the identified exposure threshold. Therefore, EPA generally refers to the ECEL and ancillary requirements as a non-prescriptive approach. In the case of 1-BP, the exposure threshold identified by EPA for certain occupational conditions of use would mitigate unreasonable risks from inhalation exposure contributed by those conditions of use for potentially exposed persons. This unit includes a summary of the proposed 1-BP WCPP, including a description of the ECEL; proposed implementation requirements and a TSCA ECEL action level; proposed monitoring requirements; a description of potential exposure controls, which consider the hierarchy of controls; information that may be used to inform PPE selection; and additional requirements proposed for recordkeeping, and worker training, participation, and notification. This unit also describes compliance timeframes for these proposed requirements. b. Existing Chemical Exposure Limit (ECEL) i. ECEL and ECEL Action Level To reduce exposures in the workplace and address the unreasonable risk of injury to health resulting from inhalation exposures to 1-BP identified under the occupational conditions of use in the TSCA 2020 Risk Evaluation for 1-BP, EPA is proposing an ECEL of 0.05 parts per million (ppm) (0.25 mg/m3) for inhalation exposures to 1-BP as an 8-hour TWA. This ECEL is based on the cancer inhalation unit risk (IUR) at a risk level of 1 × 10 −4 , which is the most sensitive hazard value across acute, chronic non-cancer, and cancer endpoints, (Refs. 12, 1). As described in the ECEL memo documenting EPA's approach for determining the exposure limit, EPA expects that, at the ECEL value of 0.05 ppm based on the cancer endpoint, a worker or ONU is protected against other endpoints, including developmental effects. EPA has determined, as a matter of risk management policy, that ensuring exposures remain at or below the ECEL would eliminate the contribution to the unreasonable risk of injury to health for 1-BP resulting from inhalation exposures in an occupational setting. EPA is proposing to establish requirements to meet an ECEL as part of the WCPP for: • Manufacturing (domestic manufacturing); • Processing as incorporation into a formulation, mixture, or reaction products; • Industrial and commercial use as a solvent in open-top and in-line batch vapor degreasing; • Industrial and commercial use as a solvent in closed-loop vapor degreasing; • Industrial and commercial use as a solvent for cleaning and degreasing in cold cleaners; • Industrial and commercial use as a solvent in aerosol spray degreaser/cleaner; and • Industrial and commercial use in other uses in electronic and electronic products and metal products; laboratory chemicals; asphalt extraction; and coatings for temperature indicators. Each owner or operator of a workplace where these conditions of use occur would be responsible for compliance with the ECEL and the associated requirements. EPA's description for how the requirements related to an ECEL would address the unreasonable risk resulting from inhalation exposures and the rationale for this regulatory approach are outlined in Units III.B.3. and V.A. If ambient exposures are kept at or below the 8-hour ECEL of 0.05 ppm, EPA expects that a potentially exposed person in the workplace would be protected against non-cancer effects resulting from occupational exposures, as well as excess risk of cancer (Ref. 12). EPA is also proposing to establish an ECEL action level of 0.03 ppm as an 8-hour TWA for 1-BP. Air concentrations at or above the action level would trigger more frequent periodic monitoring of exposures to 1-BP, as described in this unit. EPA is proposing to adopt the action level approach in implementing the TSCA ECEL, consistent with the action level approach utilized by OSHA in the implementation of OSHA standards. As explained by OSHA, due to the variable nature of employee exposures, compliance with an action level provides employers with greater assurance that their employees will not be exposed to concentrations above the PELs (Ref. 31). EPA agrees with this reasoning and, like OSHA, expects the inclusion of an ECEL action level will stimulate innovation within industry to reduce exposures to levels below the action level. Therefore, EPA has identified a need for an action level for 1-BP and is proposing a level that is lower than the 8-hour ECEL, which is in alignment with the precedented approach established under most OSHA standards. EPA is soliciting comment regarding an ECEL action level that is lower than the ECEL. In summary, EPA is proposing that each owner or operator of a workplace subject to the ECEL must ensure that no person is exposed to airborne concentration of 1-BP in excess of 0.05 ppm as an 8-hr TWA, with an action level identified as 0.03 ppm as an 8-hr TWA. For conditions of use for which requirements to meet an ECEL are being proposed, EPA believes that the regulated community has the ability to detect the values for the ECEL and ECEL action level as they are above the threshold of 1-BP monitoring devices, which can detect concentration levels as low as ≤0.0005 ppm (Ref. 12). The Agency has also identified personal breathing zone air sampling devices with a minimum limit of quantitation and level of detection at the ECEL level. (Ref. 12) EPA is requesting comment on issues around the viability of current analytical methods and detection limits for occupational 1-BP sampling and/or monitoring methods, including information on the availability of laboratory capacity needed to meet the proposed standard, and the costs associated with such testing. EPA's methodology and inputs for t [Text truncated at 120,000 characters. The full text is on the page linked above.] --- Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/fr%3A2024-17204. Public record. Not legal advice.