Reconsideration of the Dust-Lead Hazard Standards and Dust-Lead Post-Abatement Clearance Levels

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ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 745 [EPA-HQ-OPPT-2023-0231; FRL-8524-01-OCSPP] RIN 2070-AK91 Reconsideration of the Dust-Lead Hazard Standards and Dust-Lead Post-Abatement Clearance Levels AGENCY:

Environmental Protection Agency (EPA).

ACTION:

Proposed rule.

SUMMARY:

Addressing childhood lead exposure is a priority for the Environmental Protection Agency (EPA). This rule addresses health concerns for all affected communities, including children living in communities with environmental justice concerns, who have significantly higher blood lead levels (BLLs) than other children. As part of EPA's efforts to reduce childhood lead exposure, and in accordance with a U.S. Court of Appeals for the Ninth Circuit 2021 opinion, EPA is proposing to lower the dust-lead hazard standards (DLHS) from 10 micrograms per square foot (µg/ft 2 ) and 100 µg/ft 2 for floors and window sills to any reportable level as analyzed by a laboratory recognized by EPA's National Lead Laboratory Accreditation Program. This is a non-numeric value that the Agency refers to as greater than zero µg/ft 2 and may vary based on laboratory or test. While EPA's DLHS do not compel property owners or occupants to evaluate their property for lead-based paint (LBP) hazards nor take control actions, if an LBP activity such as an abatement is performed, then EPA's regulations set requirements for doing so. EPA is also proposing to change the dust-lead clearance levels (DLCL), which are the values used to determine when abatement work can be considered complete, from 10 µg/ft 2 , 100 µg/ft 2 and 400 µg/ft 2 for floors, window sills, and window troughs to 3 µg/ft 2 , 20 µg/ft 2 , and 25 µg/ft 2 , respectively. Under this proposal, the DLHS for floors and window sills would not be the same as the DLCL for floors and window sills ( i.e., the DLHS and DLCL would be decoupled). Accordingly, dust-lead hazards could remain after an abatement due to the different statutory direction that Congress provided EPA with respect to the DLCL

and window troughs to 3 µg/ft 2 , 20 µg/ft 2 , and 25 µg/ft 2 , respectively. Under this proposal, the DLHS for floors and window sills would not be the same as the DLCL for floors and window sills ( i.e., the DLHS and DLCL would be decoupled). Accordingly, dust-lead hazards could remain after an abatement due to the different statutory direction that Congress provided EPA with respect to the DLCL. Additionally, EPA is proposing to change the definition of abatement so that the recommendation for action applies when dust-lead loadings are at or above the DLCL, as well as several other amendments, including revising the definition of target housing to conform with the statute.

DATES:

Comments must be received on or before October 2, 2023. Under the Paperwork Reduction Act (PRA), 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 August 31, 2023.

ADDRESSES:

Submit your comments, identified by docket identification (ID) number EPA-HQ-OPPT-2023-0231, 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 and visiting the docket, along with more information about dockets generally, is available at https://www.epa.gov/dockets.

FOR FURTHER INFORMATION CONTACT:

t dockets generally, is available at https://www.epa.gov/dockets.

FOR FURTHER INFORMATION CONTACT:

For technical information contact: Claire Brisse, 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) 564-9004; email address: brisse.claire@epa.gov. Hearing- or speech-impaired persons may reach the telephone numbers for the contacts through TTY by calling the toll-free Federal Communications Commission's Telecommunications Relay Service at 711.

For general information contact: 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?

You may be potentially affected by this action if you conduct lead-based paint (LBP) activities in accordance with 40 CFR 745.227; if you operate a training program required to be accredited under 40 CFR 745.225; if you are a firm or individual who must be certified to conduct LBP activities or renovations in accordance with 40 CFR 745.226; or if you own, manage, and/or conduct abatement, rehabilitations or maintenance activities in most pre-1978 housing that is covered by a Federal housing assistance program in accordance with 24 CFR part 35. You may also be affected by this action if you operate a laboratory that is recognized by EPA's National Lead Laboratory Accreditation Program (NLLAP) in accordance with 40 CFR 745.90, 745.223, 745.227, and 745.327. You may also be affected by this action, in accordance with 40 CFR 745.107 and 24 CFR 35.88, as the seller or lessor of target housing, which is most pre-1978 housing. See 40 CFR 745.103 and 24 CFR 35.86. You may also be affected by this action if you are a resident of target housing, even if you would not be subject to the proposed requirements of this action

45.90, 745.223, 745.227, and 745.327. You may also be affected by this action, in accordance with 40 CFR 745.107 and 24 CFR 35.88, as the seller or lessor of target housing, which is most pre-1978 housing. See 40 CFR 745.103 and 24 CFR 35.86. You may also be affected by this action if you are a resident of target housing, even if you would not be subject to the proposed requirements of this action. Due to the change in the definition of “target housing,” you may also be affected if you are a firm or individual who must be certified to perform renovations in target housing or child-occupied facilities (COFs) in accordance with 40 CFR part 745, subpart E.

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 may include:

• Building construction (NAICS code 236), e.g., single-family housing construction, multi-family housing construction, residential remodelers.

• Specialty trade contractors (NAICS code 238), e.g., plumbing, heating, and air-conditioning contractors, painting, and wall covering contractors, electrical contractors, finish carpentry contractors, drywall and insulation contractors, siding contractors, tile and terrazzo contractors, glass, and glazing contractors.

• Real estate (NAICS code 531), e.g., lessors of residential buildings and dwellings, residential property managers, and property owners, as well as those property owners that receive assistance through Federal housing programs.

• Child day care services (NAICS code 624410).

• Elementary and secondary schools (NAICS code 611110), e.g., elementary schools with kindergarten classrooms.

• Other technical and trade schools (NAICS code 611519), e.g., training providers.

• Engineering services (NAICS code 541330) and building inspection services (NAICS code 541350), e.g., dust sampling technicians

eral housing programs.

• Child day care services (NAICS code 624410).

• Elementary and secondary schools (NAICS code 611110), e.g., elementary schools with kindergarten classrooms.

• Other technical and trade schools (NAICS code 611519), e.g., training providers.

• Engineering services (NAICS code 541330) and building inspection services (NAICS code 541350), e.g., dust sampling technicians.

• Lead abatement professionals (NAICS code 562910), e.g., firms and supervisors engaged in LBP activities.

• Testing laboratories (NAICS code 541380) that analyze dust wipe samples for lead.

• Federal agencies that own residential property (NAICS code 92511, 92811).

B. What is the Agency's authority for taking this action?

EPA is proposing this rule under the authority of sections 401, 402, 403, 404, and 406 of the Toxic Substances Control Act (TSCA), 15 U.S.C. 2601 et seq., as amended by Title X of the Housing and Community Development Act of 1992 (also known as the Residential Lead-Based Paint Hazard Reduction Act of 1992 or “Title X”) (Pub. L. 102-550) (Ref. 1) and section 237(c) of Title II of Division K of the Consolidated Appropriations Act, 2017 (Pub. L. 115-31, 131 Stat. 789), as well as sections 1004 and 1018 of Title X (42 U.S.C. 4851b, 4852d), as amended by section 237(b) of Title II of Division K of the Consolidated Appropriations Act, 2017.

Regarding the dust-lead hazard standards (DLHS), TSCA section 403 (15 U.S.C. 2683) mandates EPA to identify LBP hazards for purposes of administering Title X and TSCA Title IV. Under TSCA section 401, LBP hazards are defined as conditions of LBP and lead-contaminated dust and soil that “would result in adverse human health effects,” (15 U.S.C. 2681(10)) and lead-contaminated dust is defined as “surface dust in residential dwellings” that contains lead in excess of levels determined “to pose a threat of adverse health effects . . .” (15 U.S.C. 2681(11)).

As relevant to the dust-lead clearance levels (DLCL), TSCA section 402 (15 U.S.C

LBP and lead-contaminated dust and soil that “would result in adverse human health effects,” (15 U.S.C. 2681(10)) and lead-contaminated dust is defined as “surface dust in residential dwellings” that contains lead in excess of levels determined “to pose a threat of adverse health effects . . .” (15 U.S.C. 2681(11)).

As relevant to the dust-lead clearance levels (DLCL), TSCA section 402 (15 U.S.C. 2682) directs EPA to regulate LBP activities, which include risk assessments, inspections, and abatements. TSCA section 401 (15 U.S.C. 2681) defines abatements as “measures designed to permanently eliminate lead-based paint hazards” and the term includes “all . . . cleanup . . . and post[-]abatement clearance testing activities” (15 U.S.C. 2681(1)). EPA's statutory authority for setting the DLCL was laid out differently in Title X and TSCA Title IV than those for the DLHS. As a result, distinct from the DLHS, EPA is further directed, in promulgating the DLCL regulations, to “tak[e] into account reliability, effectiveness, and safety” (15 U.S.C. 2682(a)(1)).

Pertaining to the other amendments presented in Unit IV.F. of this preamble, TSCA section 406 (15 U.S.C. 2686) requires EPA, in consultation with the Secretary of the U.S. Department of Housing and Urban Development (HUD) and with the Secretary of the U.S. Department of Health and Human Services (HHS) to “publish, and from time to time revise, a lead hazard information pamphlet to be used in connection with this subchapter and section 4852d of title 42.” TSCA section 406 (15 U.S.C. 2686) also requires EPA's regulations to require any person performing for compensation a renovation of target housing to provide the pamphlet to the owner and occupant prior to commencing the renovation. Additionally, section 1018 of Title X (42 U.S.C. 4852d) mandates that the Lead Warning Statement to be provided in contracts for the purchase or sale of target housing include, among other language, the following text: “. .

ulations to require any person performing for compensation a renovation of target housing to provide the pamphlet to the owner and occupant prior to commencing the renovation. Additionally, section 1018 of Title X (42 U.S.C. 4852d) mandates that the Lead Warning Statement to be provided in contracts for the purchase or sale of target housing include, among other language, the following text: “. . . The seller of any interest in residential real property is required to provide the buyer with any information on lead-based paint hazards from risk assessments or inspections in the seller's possession and notify the buyer of any known lead-based paint hazards” (emphasis added). TSCA section 401 (15 U.S.C. 2681(17)) and section 1004 of Title X (42 U.S.C. 4851b), as amended by section 237(b) and (c) of Title II of Division K of the Consolidated Appropriations Act, 2017 (Pub. L. 115-31, 131 Stat. 789), define target housing as “any housing constructed prior to 1978, except housing for the elderly or persons with disabilities or any 0-bedroom dwelling (unless any child who is less than 6 years of age resides or is expected to reside in such housing) . . . .” In this context, “elderly” refers to 62 years of age or more (40 CFR 745.103).

C. What action is the Agency taking?

In 2019, EPA promulgated a final rule to lower the DLHS to 10 μg/ft 2 for floors and 100 μg/ft 2 for window sills (the 2019 DLHS Rule) (Ref. 2). In 2021, EPA promulgated a final rule to lower the DLCL to 10 μg/ft 2 for floors and 100 μg/ft 2 for window sills (the 2021 DLCL Rule) (Ref. 3). The 2019 DLHS Rule and the 2021 DLCL Rule continued a long-standing practice of setting the same levels for the DLHS and the DLCL and basing those levels in part on consideration of factors such as laboratory capacity and capabilities.

In keeping with an opinion issued by the U.S

final rule to lower the DLCL to 10 μg/ft 2 for floors and 100 μg/ft 2 for window sills (the 2021 DLCL Rule) (Ref. 3). The 2019 DLHS Rule and the 2021 DLCL Rule continued a long-standing practice of setting the same levels for the DLHS and the DLCL and basing those levels in part on consideration of factors such as laboratory capacity and capabilities.

In keeping with an opinion issued by the U.S. Court of Appeals for the Ninth Circuit in 2021 (described in Unit I.D.) that instructed EPA to consider only health factors when setting the DLHS, EPA is now proposing to change the DLHS from 10 μg/ft 2 for floors and 100 μg/ft 2 for window sills, as established in the 2019 DLHS Rule, to any reportable level of dust-lead analyzed by a NLLAP-recognized laboratory. The Agency refers to this level as greater than zero (GTZ). It is not a specific numeric level set by EPA but rather the numerically reportable level as analyzed by a NLLAP-recognized laboratory, which is sometimes referred to as a “non-numeric” value. However, that term, as used in this document, refers only to the GTZ level and should not be confused with non-numeric standards such as work practice standards. EPA believes GTZ and the standard of “any reportable level” is an appropriate DLHS based on health effects, given there is no identified level of lead in blood that does not cause adverse cognitive impacts in children, and this more protective approach is consistent with the statutory language in TSCA Section 401 that defines what a “LBP hazard” is ( i.e., as conditions of LBP and lead-contaminated dust and soil that “would result in adverse human health effects”), and with the results from the Technical Support Document (TSD). There is no evidence of a threshold below which there are not harmful effects from lead exposure, including neurobehavioral and cognitive effects on children (Refs. 4 and 5)

ion 401 that defines what a “LBP hazard” is ( i.e., as conditions of LBP and lead-contaminated dust and soil that “would result in adverse human health effects”), and with the results from the Technical Support Document (TSD). There is no evidence of a threshold below which there are not harmful effects from lead exposure, including neurobehavioral and cognitive effects on children (Refs. 4 and 5). The proposed GTZ approach represents a shift in the LBP activities program to a more inclusive DLHS, identifying dust-lead hazards in the context of TSCA Title IV as any condition that causes exposure to lead from lead-contaminated dust in target housing and child-occupied facilities. If finalized as proposed, the GTZ approach will be inclusive of any reportable level of dust-lead and will not distinguish between severe, less severe, or negligible risks. Additional discussion on GTZ can be found in Unit IV.A.1.

Additionally, EPA is proposing to revise the DLCL, set by the 2021 DLCL Rule, from 10 μg/ft 2 to 3 μg/ft 2 for dust-lead for floors, from 100 μg/ft 2 to 20 μg/ft 2 dust-lead for window sills and from 400 μg/ft 2 to 25 μg/ft 2 dust-lead for window troughs, following a consideration of reliability, effectiveness, and safety, including non-health factors such as laboratory capabilities/capacity and achievability after an abatement. EPA is also requesting comment on an alternative DLCL option of 5 μg/ft 2 dust-lead for floors, 40 μg/ft 2 dust-lead for window sills, and 100 μg/ft 2 for window troughs. If finalized as proposed, the DLHS for floors and window sills would not be the same as the DLCL for floors and window sills ( i.e., the DLHS and DLCL would be decoupled), acknowledging the different statutory direction that Congress provided EPA with respect to the DLCL. Although EPA has in the past promulgated rules setting the DLHS and e.g., laboratory capabilities/capacity, and achievability after an abatement) when setting the DLCL

loors and window sills would not be the same as the DLCL for floors and window sills ( i.e., the DLHS and DLCL would be decoupled), acknowledging the different statutory direction that Congress provided EPA with respect to the DLCL. Although EPA has in the past promulgated rules setting the DLHS and e.g., laboratory capabilities/capacity, and achievability after an abatement) when setting the DLCL.

The proposed DLCL would not impose retroactive requirements on regulated entities that have previously performed post-abatement dust wipe testing using the current DLCL of 10 μg/ft 2 for floors, 100 μg/ft 2 for window sills, and 400 μg/ft 2 for troughs, or the previous DLCL of 40 μg/ft 2 for floors, 250 μg/ft 2 for window sills, and 400 μg/ft 2 for troughs (Ref. 6). They would apply to post-abatement clearance sampling and analysis conducted after the compliance date for that portion of the regulations ( i.e., one year after publication of the final rule). Additionally, while EPA's DLHS do not compel property owners or occupants to evaluate their property for LBP hazards or take control actions (40 CFR 745.61(c)), if an LBP activity such as an abatement is performed, then EPA's regulations set requirements for doing so (40 CFR 745.220(d)). This rule, if finalized, would change the LBP activities regulations' definition of abatement to be any measure or set of measures designed to eliminate LBP hazards, in the case of dust-lead hazards, to a level below the new proposed DLCL, and would require an additional statement in the final abatement reports that states that LBP hazards (particularly dust-lead hazards) remain after an abatement if clearance testing has found that they do remain

ities regulations' definition of abatement to be any measure or set of measures designed to eliminate LBP hazards, in the case of dust-lead hazards, to a level below the new proposed DLCL, and would require an additional statement in the final abatement reports that states that LBP hazards (particularly dust-lead hazards) remain after an abatement if clearance testing has found that they do remain.

EPA is also proposing several other amendments, including: conforming changes to the definition of “target housing;” conforming the age requirements throughout the LBP regulations to under six years old; requiring that application payments, applications, and notices be submitted electronically; updating the Disclosure Rule warning statement (Ref. 7); as well as correcting an incorrect reference to the lead-hazard control pamphlet; and deleting obsolete regulatory text where language is out of date or no longer applicable. EPA is also considering adding incorporations by reference of two voluntary consensus standards already included in a relevant definition.

EPA is requesting comment on the changes described in this proposal, in particular the reliability, effectiveness, and safety of the primary and alternative DLCL options, and all other amendments discussed in Unit IV.

D. Why is the Agency taking this action?

Lead exposure has the potential to impact individuals of all ages, but it is especially harmful to young children because the developing brain can be particularly sensitive to environmental contaminants (Refs. 4 and 8). Because of this, reducing childhood lead exposure is a priority for both EPA and the Federal Government. In December 2018, the President's Task Force on Environmental Health Risks and Safety Risks to Children released the Federal Action Plan to Reduce Childhood Lead Exposures and Associated Health Impacts (Federal Lead Action Plan) (Ref

arly sensitive to environmental contaminants (Refs. 4 and 8). Because of this, reducing childhood lead exposure is a priority for both EPA and the Federal Government. In December 2018, the President's Task Force on Environmental Health Risks and Safety Risks to Children released the Federal Action Plan to Reduce Childhood Lead Exposures and Associated Health Impacts (Federal Lead Action Plan) (Ref. 9) to enhance the Federal Government's efforts to identify and reduce lead exposure while ensuring children impacted by such exposure are getting the support and care they need to prevent or mitigate any associated health effects. The Federal Lead Action Plan is helping Federal agencies to work strategically and collaboratively to reduce exposure to lead and improve children's health. On October 27, 2022, EPA released the Strategy to Reduce Lead Exposures and Disparities in U.S. Communities (Lead Strategy). The Lead Strategy lays out Agency and government-wide approaches to strengthen public health protections, address legacy lead contamination for communities with the greatest exposures and promote environmental justice. It describes how the Agency will utilize the full suite of EPA authorities, expertise, and resources to continue to reduce lead exposure. This proposed rule, which revises the DLHS and the DLCL (among other proposed regulatory changes), is an action that EPA committed to undertake in the Lead Strategy (Ref. 10).

In 2019, EPA re-evaluated the DLHS (Ref. 2). Based on that evaluation, the final rule revised the DLHS from 40 μg/ft 2 and 250 μg/ft 2 to 10 μg/ft 2 and 100 μg/ft 2 for floors and window sills, respectively. However, public health advocates filed a lawsuit in the U.S. Court of Appeals for the Ninth Circuit (the Court) seeking judicial review of the 2019 DLHS Rule as insufficiently protective. On May 14, 2021, the Court issued its opinion on the 2019 DLHS Rule

uation, the final rule revised the DLHS from 40 μg/ft 2 and 250 μg/ft 2 to 10 μg/ft 2 and 100 μg/ft 2 for floors and window sills, respectively. However, public health advocates filed a lawsuit in the U.S. Court of Appeals for the Ninth Circuit (the Court) seeking judicial review of the 2019 DLHS Rule as insufficiently protective. On May 14, 2021, the Court issued its opinion on the 2019 DLHS Rule. The Court held that “the 2019 Rule lowers the lead hazard level but not to a level sufficient to protect health as Congress has directed, because the EPA has looked to factors in addition to health.” A Cmty. Voice v. U.S. Env't Prot. Agency, 997 F.3d 983, 992 (9th Cir. 2021). The remedy the Court granted was a remand without vacatur (of the lowered DLHS), and the Court instructed EPA to consider only health factors when setting the DLHS (Ref. 11). This proposed rule is being issued to reconsider the DLHS and DLCL in light of the 2021 Court Opinion, which directed EPA to “reconsider the DLHS . . . [and] the dust-lead clearance levels . . . in the same proceeding” and affirmed that EPA could consider non-health factors when setting the DLCL. A Cmty. Voice, 997 F.3d at 995. This 2021 Court Opinion led EPA to undertake a major shift from its approach in the 2019 and 2021 final rules to the residential LBP hazard control and the LBP activities program because the Opinion found that EPA did not have the authority, when setting the DLHS, to consider non-health factors. Consistent with the 2021 Court Opinion, EPA is proposing to revise the DLHS in this rulemaking based on only health considerations. See Unit IV for more information on the proposed revisions to the DLHS and DLCL.

based on only health considerations. See Unit IV for more information on the proposed revisions to the DLHS and DLCL.

Additionally, Executive Order 13990, entitled Protecting Public Health and the Environment and Restoring Science to Tackle the Climate Crisis, directed agencies to, among other things, review certain regulations promulgated between January 20, 2017, and January 20, 2021 (Ref. 12). The 2019 DLHS and 2021 DLCL final rules were among those specifically designated for review in accordance with Executive Order 13990 (Ref. 13). As a result, the Agency was tasked with immediately considering whether the final rules were aligned with the identified national objectives from Executive Order 13990, such as listening to the science, improving public health and protecting our environment, and limiting exposure to dangerous chemicals. As a result of its own review in response to Executive Order 13990 and the 2021 Court Opinion, EPA has reconsidered the 2019 DLHS and 2021 DLCL final rules. If finalized as proposed, EPA believes this rule will result in a reduction of exposure to dust-lead (beyond the 2019 and 2021 rules).

E. What are the estimated incremental impacts of this action?

EPA has prepared an Economic Analysis (EA), which is available in the docket, of the potential incremental impacts associated with this rulemaking (Ref. 14). The analysis focused specifically on the subset of target housing and child-occupied facilities affected by this rule. Although the DLHS and DLCL do not compel specific actions under the LBP Activities Rule to address identified LBP hazards, the DLHS and DLCL are directly incorporated by reference into certain requirements mandated by HUD in the

1. Benefits

This rule would result in reduced exposure to lead, yielding benefits to residents of pre-1978 housing from avoided adverse health effects

ed by this rule. Although the DLHS and DLCL do not compel specific actions under the LBP Activities Rule to address identified LBP hazards, the DLHS and DLCL are directly incorporated by reference into certain requirements mandated by HUD in the

1. Benefits

This rule would result in reduced exposure to lead, yielding benefits to residents of pre-1978 housing from avoided adverse health effects. For the subset of adverse health effects that were quantified ( i.e., the effect of avoided IQ decreases on lifetime earnings as an indicator of improved cognitive function), the estimated monetized and annualized benefits are $1.069 billion to $4.684 billion per year using a 3% discount rate, and $231 million to $1.013 billion per year using a 7% discount rate. These benefits calculations are sensitive to the discount rate used and the range in the estimated number of lead hazard reduction events triggered by children with tested BLLs above state or Federal action levels. With respect to the latter, the wide range is driven largely by uncertainty about the BLLs at which action might be taken, since in many states the action level is currently higher than the Federal blood lead reference value.

Additionally, there are unquantified benefits. These additional benefits include avoided adverse health effects in children, including decreased attention-related behavioral problems, decreased cognitive performance, reduced post-natal growth, delayed puberty, and decreased kidney function. These additional unquantified benefits also include avoided adverse health effects in adults, including cardiovascular mortality and impacts on reproductive function and outcomes.

2. Costs

on reproductive function and outcomes.

2. Costs

This rule is estimated to result in quantified costs of $536 million to $784 million per year. These costs are expected to accrue to landlords, owners and operators of child-occupied facilities, residential remodelers, and abatement firms. Real estate agents and brokers may incur negligible costs related to the target housing definition amendment. The cost calculations are highly sensitive to the range in the estimated number of lead hazard reduction events triggered by children with elevated BLLs. In the events affected by this rule, incremental costs can be incurred for specialized cleaning used to reduce dust-lead loadings ( i.e., quantity of lead per unit of surface area) to below the clearance levels. In some instances, floors will also be sealed, overlaid, or replaced, or window sills will be sealed or repainted. Additional costs may result from the retesting of lead dust levels. Because of the lower laboratory reporting limits necessary for testing lead dust levels under this rule, incremental laboratory test costs are likely to increase. Additional potential impacts to HUD programs and their beneficiaries are discussed in Unit V.

3. Small Entity Impacts

This rule would directly impact approximately 39,000 small businesses of which 87% to 91% have cost impacts less than 1% of revenues, 9% to 12% have impacts between 1% and 3%, and 1% have impacts greater than 3% of revenues. These small entities include landlords, owners and operators of child-occupied facilities, residential remodelers, abatement firms, and real estate agents and brokers.

4. Environmental Justice

odelers, abatement firms, and real estate agents and brokers.

4. Environmental Justice

EPA is proposing this rulemaking under TSCA Title IV, as explained in Unit I.B. This rule would address lead exposure, as discussed throughout this proposal. EPA prepared an Economic Impact Analysis for this rulemaking that assessed whether there are disproportionate effects to communities from lead exposure. EPA identified an existing concern: children living in communities with environmental justice concerns have significantly higher BLLs than other children (Ref. 15). This rule addresses health concerns for all affected communities, including those identified with environmental justice concerns. As identified in EPA's Economic Impact Analysis, this rule would reduce identified disproportionate impacts to communities with environmental justice concerns. The primary and alternative regulatory options under consideration are expected to affect housing units receiving Federal assistance under HUD's LSHR and housing units with a child with a blood lead level above a Federal, state, or local blood lead threshold. Because, in general, only lower income households are eligible to receive Federal housing assistance, the occupants of housing subject to the LSHR (and thus benefitting from the proposed regulation) are considered an overburdened community. Additional details on any identified disproportionate impacts to communities with environmental justice concerns are contained in Unit IX.J. of this preamble and Section 8.6 of the economic impact analysis.

5. Children's Environmental Health

Consistent with Executive Order 13045, EPA evaluated the health and safety effects of this action on children. Children are disproportionately impacted by lead exposure

ails on any identified disproportionate impacts to communities with environmental justice concerns are contained in Unit IX.J. of this preamble and Section 8.6 of the economic impact analysis.

5. Children's Environmental Health

Consistent with Executive Order 13045, EPA evaluated the health and safety effects of this action on children. Children are disproportionately impacted by lead exposure. Children can have greater exposures than adults because they crawl on floors and often put their hands and other objects (that can have lead from dust on them) into their mouths and are more susceptible than adults to adverse health effects due to their rapid anatomical growth and physiological differences in lead uptake and metabolism. This rule protects children from these disproportionate environmental health risks.

This action is subject to EPA's Policy on Children's Health ( https://www.epa.gov/children/childrens-health-policy-and-plan ) because the rule has considerations for human health and early life exposures. Accordingly, we have evaluated the environmental health or safety effects of dust-lead exposure on children. The results of this evaluation are contained in the EA and the TSD, where the health impacts of lead exposure on children are discussed more fully (Refs. 14 and 16). The documents referenced above are available in the public docket for this action.

The primary purpose of this rule is to reduce exposure to dust-lead hazards in target housing where children reside and in child-occupied facilities. EPA's analysis indicates that there will be approximately 217,432 to 436,642 children under age six per year affected by the rule (Ref. 14). Proposing GTZ for the DLHS is a more protective approach, supported by the modeled results from the TSD and that the current state of the science does not support identifying a threshold of dust-lead exposure below which there would be no adverse human health effects

alysis indicates that there will be approximately 217,432 to 436,642 children under age six per year affected by the rule (Ref. 14). Proposing GTZ for the DLHS is a more protective approach, supported by the modeled results from the TSD and that the current state of the science does not support identifying a threshold of dust-lead exposure below which there would be no adverse human health effects. Additionally, the proposed DLCL of 3/20/25 μg/ft 2 for floors, window sills and troughs respectively, is the lowest option under consideration and according to the TSD it is estimated to be the most protective of children's IQ when compared to the other options evaluated for this proposed rulemaking.

6. Effects on State, Local, and Tribal Governments

EPA has concluded that this action has federalism implications because it imposes substantial direct compliance costs on public housing authorities that state or local governments may be

Additionally, this action contains a Federal mandate under the Unfunded Mandates Reform Act (UMRA), 2 U.S.C. 1531-1538, that may result in expenditures of $100 million or more for State, local, and Tribal governments, in the aggregate, or the private sector in any one year. Accordingly, EPA has prepared a written statement as required under section 202 of UMRA, which is summarized in Unit IX.D. and included in the public docket (Ref. 17). This action is not subject to the requirements of section 203 of UMRA because it contains no regulatory requirements that exceed the inflation-adjusted cost significance threshold or uniquely affect small governments.

ments that exceed the inflation-adjusted cost significance threshold or uniquely affect small governments.

This action would not have substantial direct effects (as specified in Executive Order 13175) on one or more federally recognized Indian Tribes. This action neither creates an obligation for Tribes to administer LBP Activities programs nor alters EPA's authority to administer these programs. However, through a live consultation on this rulemaking the Agency will solicit input from Tribal officials from the four Indian Tribes currently with authorized programs during the public comment period. EPA will ensure that the consultation materials are accessible to Tribal officials so that they may view it later as they consider submitting feedback during the public comment period. The consultation will also be open to any Tribal officials who would like to participate. If a Tribal official is interested in attending the consultation on behalf of an Indian Tribe, please consult the technical person listed under FOR FURTHER INFORMATION CONTACT .

Additionally, this rule would not have any significant or unique effects on small governments. See Unit IX. for more information on the Executive Orders.

II. Background

A. Health Effects of Lead

Lead exposure has the potential to impact individuals of all ages, but it is especially harmful to young children because the developing brain can be particularly sensitive to environmental contaminants (Refs. 4, 5, and 8). Ingestion of lead-contaminated dust is a major contributor to BLLs in children, particularly those who reside in homes built prior to 1978 (Refs. 17 and 18). Throughout early childhood, floor dust contamination is a source of lead exposure with the potential to affect children's BLLs (Ref. 20)

use the developing brain can be particularly sensitive to environmental contaminants (Refs. 4, 5, and 8). Ingestion of lead-contaminated dust is a major contributor to BLLs in children, particularly those who reside in homes built prior to 1978 (Refs. 17 and 18). Throughout early childhood, floor dust contamination is a source of lead exposure with the potential to affect children's BLLs (Ref. 20). Infants, toddlers, and young children are more highly exposed to lead through dust on floors and other surfaces at home and in child-care facilities than older children and adults because they crawl on floors and often put their hands and other objects that can have lead from dust on them into their mouths. This is the main pathway of childhood exposure to lead (Ref. 4).

Lead exposure in young children can cause neurocognitive decrements, such as reduction in intelligence as measured by IQ. Depending on the exposure and other factors, the effect may persist into adolescence and adulthood (Refs. 4, 8 and 20). In children, lead exposure can also cause adverse developmental, neurobehavioral, hematological, and immunological effects, as well as sensory effects such as hearing loss (Refs. 4, 5, and 8). In adults, lead exposure can cause adverse cardiovascular, hematological, renal, neurocognitive, neurobehavioral, immunological, and reproductive effects (Refs. 4, 5, and 8). Lead is also classified as ”reasonably anticipated to be a human carcinogen by the National Toxicology Program (NTP) (Ref. 21) and the EPA has concluded that lead exposure has a “likely causal relationship” with carcinogenesis (Ref. 4). In addition to the harmful effects experienced by the mother, lead can be transferred to the fetus during pregnancy and there is evidence that suggests adverse effects on the developing fetus including inhibited fetal growth (Refs. 4 and 5). Given young children's disproportionate exposure to dust-lead in target housing, this rulemaking principally considers their exposure and associated adverse health effects

o the harmful effects experienced by the mother, lead can be transferred to the fetus during pregnancy and there is evidence that suggests adverse effects on the developing fetus including inhibited fetal growth (Refs. 4 and 5). Given young children's disproportionate exposure to dust-lead in target housing, this rulemaking principally considers their exposure and associated adverse health effects.

The best available science informs EPA's understanding of the relationships between exposures to dust-lead, BLLs, and adverse human health effects. These relationships are summarized in the Integrated Science Assessment (ISA) for Lead, finalized in June 2013 (known as the 2013 Lead ISA) (Ref. 4), and the Agency for Toxic Substances and Disease Registry (ATSDR) Toxicological Profile for Lead, which was released by the Department of Health and Human Services in August 2020 (“ATSDR Tox Profile for Lead”) (Ref. 8). The 2013 Lead ISA is a synthesis and evaluation of scientific information on the health and environmental effects of lead, including cognitive function decrements in children (Ref. 4). The 2013 Lead ISA, as well as NIEHS' 2012 National Toxicology Program (NTP) monograph on lead, summarize the scientific evidence regarding potential health effects associated with low-level lead exposure and acknowledge uncertainties in the data (Refs. 4 and 5). Based on the epidemiological studies and the evidence available at that time, the EPA stated in the 2013 ISA that harmful effects on children's cognition as measured by IQ were observed in groups with mean BLLs as low as 2 µg/dL, and further that “A threshold for cognitive function decrements is not discernable from the available evidence ( i.e., examination of early childhood blood Pb or concurrent blood Pb in the range of < 1 to 10 μg/dL).” (Ref. 4)

vailable at that time, the EPA stated in the 2013 ISA that harmful effects on children's cognition as measured by IQ were observed in groups with mean BLLs as low as 2 µg/dL, and further that “A threshold for cognitive function decrements is not discernable from the available evidence ( i.e., examination of early childhood blood Pb or concurrent blood Pb in the range of < 1 to 10 μg/dL).” (Ref. 4). Additionally, the Federal Lead Action Plan, which was written by the President's Task Force on Environmental Health Risks and Safety Risks to Children, consisting of 17 Federal departments and offices, states that “Lead exposure to children can result from multiple sources and can cause irreversible and life-long health effects. No safe blood lead level in children has been identified.” (Refs. 9 and 22).

For further information regarding lead and its health effects, see the TSD for this rulemaking and the 2013 ISA for lead (Refs. 4 and 16).

B. Federal Actions To Reduce Lead Exposures

Title X of the Housing and Community Development Act (also known as the Residential Lead-Based Paint Hazard Reduction Act of 1992 or “Title X”), codified primarily at 42 et seq. (Ref. 1), was a Federal response to the national crisis of childhood lead exposure and assigned responsibilities to Federal agencies with the overall goal of developing a “national strategy to build the infrastructure necessary to eliminate lead-based paint hazards in all housing as expeditiously as possible” (42 U.S.C. 4851(a)(1)). Subtitle B of Title X (106 Stat. 3912 through 3924), addressing lead exposure reduction, added Title IV to TSCA (codified at 15 U.S.C. 2681 et seq. ) (Ref. 23).

Title IV to TSCA (codified at 15 U.S.C. 2681 et seq. ) (Ref. 23).

Since the establishment of Title X, EPA and HUD have promulgated both joint and separate regulatory actions in an effort to eliminate LBP hazards. Those actions include requirements for disclosure of known LBP or any known LBP hazards (Ref. 7), training and certification requirements for contractors performing LBP activities (Ref. 24), the establishment of standards that identify lead-based paint hazards and post-abatement clearance levels ( i.e., the DLHS and DLCL) (Refs. 2, 3 and 6), regulations covering renovation or remodeling activities (Refs. 25, 26 and 27), provisions for interested states, territories, and Tribes to apply for and receive authorization to administer their own LBP Activities and renovation, repair and painting (RRP) programs, and requirements to control LBP and LBP hazards in federally-assisted target housing (Ref. 28). Additional description of and background on Federal actions to reduce lead exposure to can be found in the 2021 DLCL rulemaking (Ref. 3).

In addition, EPA has developed a Lead Strategy to lay out an all-of-EPA plan to strengthen public health protections and address legacy lead contamination for communities with the greatest exposures and promote environmental justice ( https://www.epa.gov/lead/final-strategy-reduce-lead-exposures-and-disparities-us-communities ). EPA plans to continue its work to equally protect people of all races, ethnic groups, income levels, disabilities, and life stages, including young children and pregnant women, who are the most vulnerable to the toxic effects of lead. The proposed actions in this notice are part of those efforts, as dust-lead from lead-based paint remains one of the leading causes of lead exposure in the United States (Ref. 10).

ue its work to equally protect people of all races, ethnic groups, income levels, disabilities, and life stages, including young children and pregnant women, who are the most vulnerable to the toxic effects of lead. The proposed actions in this notice are part of those efforts, as dust-lead from lead-based paint remains one of the leading causes of lead exposure in the United States (Ref. 10).

C. Applicability and Uses of DLHS and DLCL

The DLHS and DLCL reconsidered in this regulation support EPA's lead-based paint (LBP) activities program ( i.e., inspections, risk assessments, and abatements) and disclosure program, both of which apply to target housing ( i.e., most pre-1978 housing) and COFs (pre-1978 non-residential properties where under the current regulation, children 6 years of age or under spend a significant amount of time such as daycare centers and kindergartens) (codified at 40 CFR part 745, subpart L). The statutory definition of target housing was amended by Congress in 2017, and EPA is planning to make the necessary conforming regulatory changes, including changing the age to under six years of age, within this rulemaking; see Unit IV.F.1. for more information. Apart from COFs, no other public or commercial buildings are covered by this proposal.

The DLHS and DLCL are incorporated into requirements for risk assessment and post-abatement work. When conducted, LBP activities must be performed by a certified individual or firm (40 CFR 745.220) in accordance with the work practices outlined in the 1996 LBP Activities Rule (40 CFR 745.227). EPA administers the LBP activities program only where states (including the District of Columbia and the Commonwealth of Puerto Rico), territories, or Tribes are not authorized by EPA to operate their own lead abatement programs (see 40 CFR part 745, subpart Q). Currently the states in which the LBP program is administered by EPA are Alaska, Arizona, Florida, Idaho, Montana, Nevada, New Mexico, New York, South Carolina, South Dakota, and Wyoming

here states (including the District of Columbia and the Commonwealth of Puerto Rico), territories, or Tribes are not authorized by EPA to operate their own lead abatement programs (see 40 CFR part 745, subpart Q). Currently the states in which the LBP program is administered by EPA are Alaska, Arizona, Florida, Idaho, Montana, Nevada, New Mexico, New York, South Carolina, South Dakota, and Wyoming. In addition, EPA administers the LBP program in the territories of American Samoa, Guam, Northern Marianas, and the U.S. Virgin Islands, as well as most Tribal Lands. All other states have EPA-authorized LBP programs. Additionally, the Cherokee Nation, Upper Sioux Community, Lower Sioux Indian Community, and the Bois Forte Band of Chippewa have EPA-authorized LBP programs.

To administer the disclosure program, EPA and HUD jointly developed regulations (known as the Disclosure Rule under section 1018 of Title X (42 U.S.C. 4852d)) requiring a seller or lessor of most pre-1978 housing to disclose the presence of any known LBP and/or LBP hazards, such as soil-lead hazards or dust-lead hazards, to the purchaser or lessee (24 CFR part 35, subpart A; 40 CFR part 745, subpart F). Under these regulations, the seller or lessor also must provide the purchaser or lessee any available records or reports “pertaining to” LBP and/or LBP hazards (40 CFR 745.107(a)(4); 24 CFR 35.88(a)(4)). Leases of target housing are exempt from disclosure requirements in limited circumstances, such as where the housing has been found to be LBP free by a certified inspector (24 CFR 35.82; 40 CFR 745.101). For more information on how the DLHS and DLCL revisions impact various EPA and HUD programs, see Unit V.A. and Unit V.B.

1. Dust-Lead Hazard Standards

spector (24 CFR 35.82; 40 CFR 745.101). For more information on how the DLHS and DLCL revisions impact various EPA and HUD programs, see Unit V.A. and Unit V.B.

1. Dust-Lead Hazard Standards

The DLHS support and implement major provisions of TSCA Title IV and provide the basis for risk assessors to determine whether dust-lead hazards are present during a risk assessment or a lead hazard screen. A risk assessment may be required by the LSHR where dust wipe testing occurs to comply with the LSHR ( e.g., for certain properties receiving Federal assistance) or by other law or regulation where dust-lead testing occurs in response to the discovery of a child with a BLL that exceeds a Federal, state, or local threshold. Additional information on the LSHR and the subparts which require risk evaluation is discussed in the EA (Ref. 14). The objective of a risk assessment is to determine, and then report the existence, nature, severity, and location of LBP hazards in residential dwellings and COFs through an on-site investigation, which includes both a visual assessment and a collection of environmental samples. The environmental samples include, among other things, dust wipe samples (taken using documented methodologies as defined in 40 CFR 745.227(a)(3)) from floors and window sills. Those samples are required to be analyzed by a laboratory that is recognized under NLLAP, which is an EPA program that defines the minimum requirements and abilities that laboratories must meet to attain EPA recognition as an accredited testing laboratory (the standards for the program are laid out in the Laboratory Quality System Requirements) (Ref. 29). A risk assessor compares the results of the dust wipe samples to the current DLHS. If the dust-lead loadings from the samples are at or above the applicable DLHS, then a dust-lead hazard is present (40 CFR 745.227(d))

ratories must meet to attain EPA recognition as an accredited testing laboratory (the standards for the program are laid out in the Laboratory Quality System Requirements) (Ref. 29). A risk assessor compares the results of the dust wipe samples to the current DLHS. If the dust-lead loadings from the samples are at or above the applicable DLHS, then a dust-lead hazard is present (40 CFR 745.227(d)).

Ultimately, the risk assessor prepares a risk assessment report for the property owner or manager, which lists any LBP hazards (including a dust-lead hazard) that were found and includes any recommendations for next steps, such as acceptable options for controlling the hazards via interim controls and/or abatement. These options are intended to allow the property owner to make an informed decision about what actions to take to protect the health of current and future residents. Under EPA's rule, a risk assessment/risk assessment report does not compel or require action;

A lead hazard screen also includes a visual inspection and collection of environmental samples, although it is not as comprehensive as a risk assessment or conducted as often. A lead hazard screen may be used to determine if a full risk assessment is necessary. During a lead hazard screen, a risk assessor checks for deteriorated LBP and collects two composite dust samples (in residential dwellings), one from floors and one from window sills (more composite dust samples are required in multi-family dwellings or COFs). Samples are taken using documented methodologies. The risk assessor prepares a lead hazard screen report but is not required to include determinations about the LBP hazards or recommendations for interim controls and/or abatement but could include information on whether a follow-up risk assessment is warranted (40 CFR 745.227(c)).

Both risk assessments and lead hazard screens can only be performed by risk assessors certified according to the procedures in 40 CFR 745.226.

ad hazard screen report but is not required to include determinations about the LBP hazards or recommendations for interim controls and/or abatement but could include information on whether a follow-up risk assessment is warranted (40 CFR 745.227(c)).

Both risk assessments and lead hazard screens can only be performed by risk assessors certified according to the procedures in 40 CFR 745.226.

2. Dust-Lead Clearance Levels

The DLCL are incorporated into the post-abatement work practices outlined in the LBP Activities Rule and represent “the amount of lead in dust on a surface following completion of an abatement activity” (40 CFR 745.227, 745.223) (Ref. 24). TSCA section 401 defines abatements as, “measures designed to permanently eliminate lead-based paint hazards,” (15 U.S.C. 2681(1)), while interim controls are “designed to temporarily reduce human exposure or likely exposure to lead-based paint hazards,” (40 CFR 745.83 and 745.223). Abatement and/or interim controls could be recommended in a risk assessment report to inform the property owner about potential future action(s) they could take. After an abatement is complete, a risk assessor or inspector determines whether there are any “visible amounts of dust, debris or residue,” which will need to be removed before clearance sampling takes place (40 CFR 745.227(e)(8)). Once the area is free of visible dust, debris, and residue, and one hour or more after final post-abatement cleaning ceases, clearance sampling for dust-lead (via dust wipe samples) can take place and will be conducted “using documented methodologies that incorporate adequate quality control procedures” (40 CFR 745.227(e)(8)). Only a properly trained and certified risk assessor or inspector can conduct clearance sampling. An NLLAP-recognized laboratory must analyze the dust wipe samples and a risk assessor or inspector must compare the results from window sills, floors, and window troughs to the appropriate DLCL

“using documented methodologies that incorporate adequate quality control procedures” (40 CFR 745.227(e)(8)). Only a properly trained and certified risk assessor or inspector can conduct clearance sampling. An NLLAP-recognized laboratory must analyze the dust wipe samples and a risk assessor or inspector must compare the results from window sills, floors, and window troughs to the appropriate DLCL.

Every post-abatement sample must test below the DLCL in order to fulfill the post-abatement work practices of the LBP Activities Rule. If a single sample is equal to or greater than the corresponding DLCL, then the abatement fails clearance and the components represented by the failing sample must be recleaned and retested (40 CFR 745.227(e)(8)). After all dust wipe samples show dust-lead loadings below the DLCL, an abatement report is prepared (in accordance with the requirements in 40 CFR 745.227(e)(10)), copies of any reports required under the LBP Activities Rule are provided to the building owner (and to potential lessees and purchasers under the LBP Disclosure Rule by those building owners or their agents), and all required records are retained by the abatement firm or by the individuals who developed each report for no fewer than three years (40 CFR 745.227(i)).

D. Limitations of DLHS and DLCL

The DLHS are intended to identify dust-lead hazards during risk assessments, while the DLCL are part of post-abatement work practices, ensuring that clearance is achieved. Both regulatory values have several key limitations. Since the DLHS and DLCL were established and revised for the purposes of Title X and TSCA Title IV only, they do not apply to housing and COFs built during or after 1978, nor do they apply to pre-1978 housing that does not meet the definition of target housing (40 CFR 745.61 and 745.223)

ement work practices, ensuring that clearance is achieved. Both regulatory values have several key limitations. Since the DLHS and DLCL were established and revised for the purposes of Title X and TSCA Title IV only, they do not apply to housing and COFs built during or after 1978, nor do they apply to pre-1978 housing that does not meet the definition of target housing (40 CFR 745.61 and 745.223). If one chooses to apply the DLHS or the DLCL to situations beyond the scope of Title X and TSCA Title IV, care must be taken to ensure that the action taken in such settings is appropriate, and that the action is adequate to provide any necessary protection for children or other individuals exposed.

These standards cannot be used to identify that housing is free from all risks from exposure to lead including but not limited to dust-lead, soil-lead, or lead in drinking water, as risks are dependent on many factors. For instance, the physical condition of a property that contains LBP may change over time, resulting in an increase in risk. Plus, EPA's DLHS do not require the owners of properties covered by this proposal to evaluate their properties for the presence of dust-lead hazards, nor to take action if dust-lead hazards are identified (although these standards can be incorporated into certain requirements mandated by state, Tribal and local governments, as well as other Federal agencies). Additionally, consistent with the 2021 Court Opinion which instructed EPA to consider only health factors when setting the DLHS and affirmed that EPA could consider other factors ( i.e., reliability, effectiveness, and safety) when setting the DLCL, EPA is proposing that the DLCL would be greater than the DLHS based on its consideration of other factors ( e.g., laboratory capabilities/capacity, and achievability after an abatement). As a result, and given the change in the definition of abatement discussed in Unit IV.D

LHS and affirmed that EPA could consider other factors ( i.e., reliability, effectiveness, and safety) when setting the DLCL, EPA is proposing that the DLCL would be greater than the DLHS based on its consideration of other factors ( e.g., laboratory capabilities/capacity, and achievability after an abatement). As a result, and given the change in the definition of abatement discussed in Unit IV.D. of this preamble, there may be dust-lead left behind that meets the definition of an LBP hazard after an abatement is considered complete, due to dust-lead levels that are reportable but are less than the proposed DLCL. Also, as has been the case historically, achieving the DLCL after an abatement does not mean that the home is free from all exposure to lead, including from other media such as soil-lead or lead in drinking water. EPA will continue coordinating with other Federal agencies to encourage best practices for owners and occupants of post-abatement properties to conduct ongoing maintenance that will help to continue to lower dust-lead levels, as well as work collectively as an Agency to reduce overall lead exposure through all pathways.

E. Litigation Overview

As previously discussed, EPA revised the DLHS to 10 μg/ft 2 for floors and 100 μg/ft 2 for window sills in a final rule in July 2019 (Ref. 2). Later that same year, multiple organizations, including A Community Voice, California Communities Against Toxics, Healthy Homes Collaborative, New Jersey Citizen Action, New York City Coalition to End Lead Poisoning, Sierra Club, United Parents Against Lead National, and We Act for Environmental Justice, petitioned the U.S. Court of Appeals for the Ninth Circuit to review the 2019 DLHS Rule (Ref. 30).

isoning, Sierra Club, United Parents Against Lead National, and We Act for Environmental Justice, petitioned the U.S. Court of Appeals for the Ninth Circuit to review the 2019 DLHS Rule (Ref. 30).

In response to the Petition for Review, on May 14, 2021, the Court remanded the 2019 DLHS Rule without vacatur and directed EPA to revisit it in conjunction with a reconsideration of the DLCL (Ref. 11). In its opinion accompanying the remand, the Court instructed EPA to consider only health factors when setting the DLHS and affirmed that EPA could continue to consider non-health factors when setting the DLCL. Specifically, the 2021 Court Opinion held that EPA's 2019 DLHS Rule “looked to other factors, A Cmty. Voice, 997 F.3d at 989 and 990. The Court also held that “TSCA [Title] IV gives the EPA latitude to consider `reliability, effectiveness, and safety'” when promulgating regulations “[w]ith respect to implementation, including abatement,” thus enabling consideration of practicability when setting the DLCL. Id. at 995. The Court explained that “[t]his is in line with the overall statutory scheme that differentiates between identification of hazards and implementation of remedial measures.” Id. The Court also explained elsewhere in the 2021 Court Opinion that, if an agency relies on uncertainty for regulatory action or inaction, the agency must “provide reasons why uncertainty justifies their actions” Id. at 993. Consistent with the 2021 Court Opinion, EPA is proposing to revise the DLHS in this rulemaking based only on health considerations.

In addition, the Court held that EPA violated TSCA Title IV by leaving the soil-lead hazard standards (SLHS) at the values set in 2001, reasoning that EPA had an ongoing duty to update the standards. The SLHS identify lead-contaminated soil at target housing and pre-1978 COFs that would result in adverse human health effects. Soils that contain lead at levels determined to be hazardous to human health are considered contaminated

EPA violated TSCA Title IV by leaving the soil-lead hazard standards (SLHS) at the values set in 2001, reasoning that EPA had an ongoing duty to update the standards. The SLHS identify lead-contaminated soil at target housing and pre-1978 COFs that would result in adverse human health effects. Soils that contain lead at levels determined to be hazardous to human health are considered contaminated. Lead inspectors, risk assessors, and abatement professionals use the SLHS to determine if soil-lead hazards are present and to inform options for reducing risk. Due to resource considerations and to act as expeditiously as possible to revise the DLHS and DLCL, EPA will address the SLHS in a separate rulemaking. (For more background on resource constraints under TSCA, please see Congressional testimony from EPA leadership (Refs. 31 and 32)). EPA listed this SLHS rulemaking in the Spring 2023 Unified Agenda of Regulatory and Deregulatory Actions under RIN 2070-AL12 as a long-term action, indicating the Agency's commitment to meet the statutory requirement of addressing the SLHS revision but indicating that the Agency does not expect to propose this action in the next 12 months (Ref. 33). EPA has however, initiated work on the SLHS rulemaking and, as this rulemaking on the DLHS and DLCL progresses and as resources allow, EPA intends to work further on the technical analysis for SLHS in preparation for the SLHS rulemaking. The Agency also intends to build off of the technical analysis utilized for this rulemaking for the SLHS rulemaking, mirroring where possible so as to reduce resource constraints and considerations.

The Court also held that, to be consistent with its health-only interpretation of an LBP hazard ( i.e., soil, dust), the definition of LBP must “encompass all levels of lead in paint that lead to adverse human health effects.” A Cmty. Voice, 997 F.3d at 992. The Court stated that “EPA ha[d] not explained why uncertainty justifies its decision to leave the definition of lead-paint as-is.” Id. at 993

he Court also held that, to be consistent with its health-only interpretation of an LBP hazard ( i.e., soil, dust), the definition of LBP must “encompass all levels of lead in paint that lead to adverse human health effects.” A Cmty. Voice, 997 F.3d at 992. The Court stated that “EPA ha[d] not explained why uncertainty justifies its decision to leave the definition of lead-paint as-is.” Id. at 993. The Court also noted that much knowledge has been gained since Congress adopted the 1992 definition and that the U.S. Consumer Product Safety Commission (CPSC) has adopted a regulation that bans the production of paint with lead content of over 0.009 percent by weight. The CPSC standard, however, applies to new paint while TSCA is concerned with the hazards posed by existing paint in pre-1978 structures and different information and considerations are relevant in that context. The definition of LBP (1.0 milligrams per square centimeter or more than 0.5 percent by weight) is incorporated throughout the LBP regulations, and application of this definition is central to how the LBP program functions. In the 2019 DLHS Rule, EPA discussed the Agency's need for more information to establish a statistically valid causal relationship between concentrations of lead at low levels in paint and dust lead loadings that cause lead exposure. Additionally, information is still needed to quantify the direct ingestion of paint through consumption of paint chips or through teething on painted surfaces. Finally, it is important to understand how capabilities among various LBP testing technologies would be affected under a possible revision to the definition, such as field portable X-ray fluorescent devices which are the primary tools for lead inspections and risk assessments. They are calibrated to the current definition of LBP, and so EPA needs to fully understand the repercussions such a revision to the definition may have on these portable field technologies to ensure the technological feasibility

fected under a possible revision to the definition, such as field portable X-ray fluorescent devices which are the primary tools for lead inspections and risk assessments. They are calibrated to the current definition of LBP, and so EPA needs to fully understand the repercussions such a revision to the definition may have on these portable field technologies to ensure the technological feasibility.

EPA plans to sponsor a technical workshop to obtain additional information needed to address data gaps related to the definition of LBP that were outlined in the 2019 DLHS Rule. In preparation for the LBP technical workshop, the Agency performed a literature review for sources relevant to the definition of LBP, consulted other Federal agencies, and refreshed materials done for the 2019 rulemaking. With this information the data gaps have been refined to add further specificity, which allows for a more targeted scope for both continued investigation and for the technical workshop. The more specific data gaps that EPA continues to investigate include empirical data on the relationship between low levels of lead in paint and dust-lead, as well as data on the common exposure scenarios that may inform this relationship (for example, dust-lead generation during a renovation scenario versus slowly deteriorating paint). Currently the available empirical data and modeling approaches for estimating the relationship between lead content in on-the-wall paint and lead in related environmental media, including dust, are applicable at or above the current LBP definition. EPA believes that to use the available empirical data and modeling approaches to estimate dust-lead loadings at low levels of lead in paint (particularly levels that are lower than the current definition by an order of magnitude or more) will introduce significant uncertainty to any estimations

d in related environmental media, including dust, are applicable at or above the current LBP definition. EPA believes that to use the available empirical data and modeling approaches to estimate dust-lead loadings at low levels of lead in paint (particularly levels that are lower than the current definition by an order of magnitude or more) will introduce significant uncertainty to any estimations. Data and models applicable to lower levels of lead in paint are needed to develop an approach to estimate dust-lead from low levels of lead in paint, which will allow EPA to estimate incremental blood lead changes and associated health effect changes that may occur due to low levels of lead in paint. For the ingestion exposure pathway, EPA is exploring possible modeling solutions as well as seeking quantitative measures of ingestion and exposure (such as data on duration and frequency of consumption, and common paint chip characteristics). Studies on this subject have documented this behavior as a risk factor for exposure to lead from LBP, however the studies have not provided quantitative estimates of paint ingestion, which are needed to quantify exposure. Lastly, EPA continues to investigate constraints to the field measurement options for low levels of lead in paint. Different technologies have different limitations in accuracy, processing time, detection limits, accessibility, and destructiveness among other factors. These practical considerations are important to consider in understanding how a change in the definition may affect the ability of the regulated community to use certain technologies, potentially impacting the residents of target housing and occupants of COFs

hnologies have different limitations in accuracy, processing time, detection limits, accessibility, and destructiveness among other factors. These practical considerations are important to consider in understanding how a change in the definition may affect the ability of the regulated community to use certain technologies, potentially impacting the residents of target housing and occupants of COFs. On top of these data gaps, EPA is exploring the relationship between the two different units used in the current definition (milligram per

Similar to the SLHS rulemaking, due to resource considerations and EPA's interest in acting as expeditiously as possible to revise the DLHS and DLCL and to hold the aforementioned LBP technical workshop, EPA will address the definition of lead-based paint in a separate rulemaking. EPA has listed this rulemaking on the definition of LBP in the Spring 2023 Unified Agenda of Regulatory and Deregulatory Actions under RIN 2070-AL11 as a long-term action, indicating the Agency's commitment to meet the statutory requirement of addressing the definition of LBP revision but that the Agency does not expect to propose this action in the next 12 months (Ref. 33).

Rulemakings such as those necessary for revisions to SLHS and the definition of LBP are complex, highly resource-intensive activities that usually occur as part of options development and decision-making. A rulemaking's development generally entails scientific, economic, legal, and other technical analyses. For many rulemakings, this includes research and data gathering, which itself can sometimes necessitate exercising other information collection tools and following appropriate procedural requirements ( e.g., Paperwork Reduction Act). To develop a rulemaking, EPA also often consults with governments and key stakeholders. Federal law may require such consultations based on anticipated regulatory impacts ( e.g., the Unfunded Mandates Reform Act and the Regulatory Flexibility Act)

sometimes necessitate exercising other information collection tools and following appropriate procedural requirements ( e.g., Paperwork Reduction Act). To develop a rulemaking, EPA also often consults with governments and key stakeholders. Federal law may require such consultations based on anticipated regulatory impacts ( e.g., the Unfunded Mandates Reform Act and the Regulatory Flexibility Act). Additionally, various executive orders may also require the Agency to engage in such consultations.

A rulemaking package often requires the development of complex supporting documents including an EA and a TSD, similar to those included alongside this reconsideration rulemaking (Refs. 14 and 16). A complete TSD includes several components which may require internal and external stakeholder dialogue and scientific peer review, including model and input data revisions, health and exposure metrics of interest, environmental fate and exposure mechanisms for either soil or the definition of LBP, characterization of uncertainties in modeling, and literature reviews (which have not been done for soil since before the 2001 LBP Rule was finalized). If existing models and analytical methods are insufficient to conduct the analysis to support the rulemaking, then they must be developed as part of the technical work done in support of the rulemaking effort. Developing new models can take a considerable length of time and novel analyses may require peer-review, further extending the rulemaking timeline. The magnitude and effort of an SLHS TSD would mirror previous DLHS and DLCL TSDs; see the technical documents prepared in support of the 2019 DLHS Final Rule, the 2021 DLCL Final Rule, or this reconsideration rulemaking (Refs. 16, 19, and 34)

g effort. Developing new models can take a considerable length of time and novel analyses may require peer-review, further extending the rulemaking timeline. The magnitude and effort of an SLHS TSD would mirror previous DLHS and DLCL TSDs; see the technical documents prepared in support of the 2019 DLHS Final Rule, the 2021 DLCL Final Rule, or this reconsideration rulemaking (Refs. 16, 19, and 34).

An EA includes various components such as a description of the need for Federal regulation; a profile of affected industries and populations; an overview of existing Federal, state and local regulations; a specification of the baseline state of the world and estimate of the number of events affected by the regulation; thorough analysis on the consequences of regulatory policy being considered and how regulated entities will respond; quantification and monetization of the regulation's costs, benefits, and net benefits; a description of unquantified or qualitative benefit descriptions; and an assessment of uncertainty surrounding estimates. An EA also includes various additional analyses related to statutory compliance and Executive orders, including but not limited to RFA/SBREFA (Small Business Impacts), UMRA (Unfunded State, Local, or Tribal Mandates), PRA (Paperwork Reduction), Executive Order 12898 (Environmental Justice), Executive Order 13045 (Protection of Children), Executive Order 13132 (Federalism), Executive Order 13175 (Coordination with Tribal Governments), and Executive Order 13211 (Energy Effects). A rulemaking also involves preparing Federal Register documents to present, generally, the preamble to and regulatory text of the proposed and final rule

duction), Executive Order 12898 (Environmental Justice), Executive Order 13045 (Protection of Children), Executive Order 13132 (Federalism), Executive Order 13175 (Coordination with Tribal Governments), and Executive Order 13211 (Energy Effects). A rulemaking also involves preparing Federal Register documents to present, generally, the preamble to and regulatory text of the proposed and final rule. Such published documents reflect the culmination of the development and review of the complex supporting documents and the resulting decision-making, which includes internal steps at the Agency to reach office wide agreement, as well as external to the Agency, such as holding potential public consultations, completing interagency review and convening a Small Business Advocacy Review (SBAR) Panel as necessary. These processes can also take many months or years. The proposed and final rules also present statutory and Executive Order review analyses. The Agency may also need to publish Federal Register documents to extend or reopen public comment periods—or even to announce new public comment periods related to a Notice of Data Availability or a supplemental Notice of Proposed Rulemaking—should new information become available, or the Agency determine that it needs to alter its proposal before taking final action.

The current rulemaking on the DLHS and DLCL is one more step toward complete implementation of TSCA Title IV. Given existing resource constraints and the additional complications for the SLHS and the definition of LBP discussed earlier in this section, EPA does not believe that either the SLHS or the definition of LBP could have been reconsidered on this current rulemaking's timeline. Instead, EPA will reconsider the SLHS and the definition of LBP as important next steps. Courts “have recognized that, under the `pragmatic' one-step-at-a-time doctrine, `agencies have great discretion to treat a problem partially' and `regulat[e] in a piecemeal fashion.' ” Transportation Div

ther the SLHS or the definition of LBP could have been reconsidered on this current rulemaking's timeline. Instead, EPA will reconsider the SLHS and the definition of LBP as important next steps. Courts “have recognized that, under the `pragmatic' one-step-at-a-time doctrine, `agencies have great discretion to treat a problem partially' and `regulat[e] in a piecemeal fashion.' ” Transportation Div. of the Int'l Ass'n of Sheet Metal, Air, Rail & Transportation Workers v. Fed. R.R. Admin., 10 F.4th 869, 875 (D.C. Cir. 2021) (quoting Ctr. for Biological Diversity v. EPA, 722 F.3d 401, 409-10 (D.C. Cir. 2013)); cf. Massachusetts v. EPA, 549 U.S. 497, 524 (2007) (recognizing that “[a]gencies, like legislatures, do not generally resolve massive problems in one fell regulatory swoop”). EPA intends to conduct rulemakings on the SLHS and the definition of LBP, as identified in the Spring 2023 Unified Agenda of Regulatory and Deregulatory Actions, to address the issues identified by the Ninth Circuit in its May 2021 opinion (Refs. 11 and 33).

III. Technical Analyses

In its evaluation of options for reconsidering the DLHS and DLCL, EPA estimated children's BLL and associated IQ decrements. Estimated BLL and IQ decrements provide the means to quantify the effects that long-term exposure to the analyzed dust-lead loading levels can have on young children. The TSD (Ref. 16) and EA (Ref. 14) accompanying this proposed rulemaking estimated the expected impacts of the candidate DLHS and DLCL options on BLLs and associated IQ decrements of exposed children in target housing. See Unit IV. on the

g. See Unit IV. on the

The TSD uses both mechanistic and empirical models to predict the possible BLLs of children in target housing exposed to homogenous candidate values for dust-lead levels ( e.g., candidate options for the DLHS) and characterizes the probabilistic variability due to biological response and variation in other sources of lead exposure at each possible candidate dust-lead level. The first approach used mechanistic modeling that includes use of age-specific ingestion rates, activity patterns, and background exposures. The second approach used empirical data that includes co-reported dust-lead and BLL measurements in the homes of children; these dust-lead and BLL data are used to develop an empirical relationship to estimate BLLs for each candidate dust-lead level. Both approaches (mechanistic and empirical) are compared to increase our confidence in the estimates of the relationship between dust-lead loadings and BLL (Section 6.3 of the TSD). The various components of the model and input parameters used in this rulemaking have been the subject of multiple Science Advisory Board Reviews, workshops and publications in the peer reviewed literature focused on dust-lead (Refs. 18, 35, 36, 37, 38, and 39). Specifically, the mechanistic blood lead modeling for this rulemaking reflects the application of an extensively peer-reviewed model by EPA (the Stochastic Human Exposure and Dose Simulation—Integrated Exposure Uptake Biokinetic model coded in R, referred to as R-SHEDS-IEUBK) using updated data sources and tailored to the dust-lead target housing scenario, described in depth in Appendix E of the TSD.

ng scenario, described in depth in Appendix E of the TSD.

Detailed discussion of the limitations and uncertainties in blood lead modeling at the low BLL and exposure levels considered for this rulemaking can be found in Section 8 of the TSD (Ref. 16). In brief, IEUBK, as a standalone biokinetic model, was evaluated for performance in groups for which the geometric mean BLL is as low as 2.3 µg/dL. Some of the groups at the lowest levels of dust lead exposure modeled for this rulemaking had mean estimated BLL lower than this value (between 0.81 and 1.12 µg/dL depending upon age), which are outside the range for which the underlying biokinetic model (IEUBK) was evaluated. In order to address this concern, EPA conducted an evaluation of the R-SHEDS-IEUBK model used in this analysis with a dataset for which the geometric mean BLL in children aged 1 to 2 years old is 1.09 µg/dL. This evaluation found that the R-SHEDS-IEUBK model had good agreement with the reference dataset at low percentiles, as well as at the median and at the 95th percentile. See Table 8-2 and Appendix D in the TSD (Ref. 16).

In contrast to the TSD, which estimates the health risk and exposure associated with dust-lead loading candidates for a hypothetical subpopulation of children in target housing without consideration to how many children are actually affected by the rule, the EA estimates benefits that accrue to only the subpopulation which would be impacted by the DLHS and DLCL revisions. Rather than assuming all households living in target housing are impacted by the regulatory change, the EA instead estimates benefits solely for instances when dust-lead levels would be tested. These instances of dust wipe testing are henceforth referred to as “triggering events.” For the subpopulation of children who are affected by these events, the EA estimates quantified benefits from avoided IQ losses

an assuming all households living in target housing are impacted by the regulatory change, the EA instead estimates benefits solely for instances when dust-lead levels would be tested. These instances of dust wipe testing are henceforth referred to as “triggering events.” For the subpopulation of children who are affected by these events, the EA estimates quantified benefits from avoided IQ losses. The EA uses real world data to characterize (1) variability in the housing stock that is affected, (2) how surface-by-surface dust-lead loadings change due to the DLHS/DLCL, (3) the number of children living in affected housing units, and (4) resultant changes in BLLs and IQ that are expected. In modeling the relationships between dust-lead loadings and BLL/IQ, the EA presents results based on both the empirical and mechanistic approaches laid out in the TSD. EPA considered several methods to impute the relationship between BLL and IQ below the lowest BLLs observed in the underlying empirical data, and a range of IQ loss results based on the methods considered are presented in the EA (see TSD section 5 and EA section 6.4). The IQ loss estimates presented in Unit IV. and in Section 7 of the TSD result from a linearization method, which resulted in the most conservative estimates of IQ loss.

Both the TSD and the EA present probabilistic distributions of estimated change in BLL or IQ decrement for young children up to the age of six. However, these distributions represent subpopulations of exposed children characterized in differing ways. The TSD presents the expected response for a hypothetical exposure, accounting for varying sources of background exposure ( e.g., food, soil, water) and biological variability. The EA estimates expected results from triggering events, recognizing exposure to the hypothetical conditions in the TSD are rare as dust-lead levels across target housing are generally quite low and existing abatements/interim controls typically overshoot the clearance levels considerably

accounting for varying sources of background exposure ( e.g., food, soil, water) and biological variability. The EA estimates expected results from triggering events, recognizing exposure to the hypothetical conditions in the TSD are rare as dust-lead levels across target housing are generally quite low and existing abatements/interim controls typically overshoot the clearance levels considerably. Thus, the distributions of BLLs and IQ decrements presented in the TSD represent the impact of children's exposures to hypothetical dust-lead levels while the EA estimates distributions of BLLs and IQ decrements across all children living in housing that would be directly impacted by this proposed rule.

The analyses that EPA developed and presented in the TSD and EA for this rule were specifically designed to estimate BLLs and associated effects on IQ that might accrue to the subpopulation, i.e., children living in pre-1978 housing. EPA notes that its different program offices estimate exposures for different populations, different media, and under different statutory requirements and thus different models or parameters may be a better fit for their purposes. As such, the approach and modeling parameters chosen for this rulemaking should not necessarily be construed as appropriate for, or consistent with, those of other EPA programs.

IV. Proposed Rule

As explained in Unit II.E., the 2021 Court Opinion of the U.S. Court of Appeals for the Ninth Circuit held that EPA must reconsider the DLHS in conjunction with the DLCL (Ref. 11). Accordingly, EPA is proposing to change the DLHS from 10 µg/ft 2 and 100 µg/ft 2 for floors and window sills to a non-numeric value called GTZ or any reportable level of dust-lead analyzed by an NLLAP-recognized laboratory. Lowering the DLHS (independent of the DLCL revisions) provides the regulatory benefit of additional disclosure of LBP hazards in target housing and COFs

ith the DLCL (Ref. 11). Accordingly, EPA is proposing to change the DLHS from 10 µg/ft 2 and 100 µg/ft 2 for floors and window sills to a non-numeric value called GTZ or any reportable level of dust-lead analyzed by an NLLAP-recognized laboratory. Lowering the DLHS (independent of the DLCL revisions) provides the regulatory benefit of additional disclosure of LBP hazards in target housing and COFs. This results in an estimated increase in individuals who are aware of the presence of dust-lead and the various actions that can be taken to minimize dust-lead hazards and take actions to protect themselves from exposure. See Unit IV.A.1. for additional information describing the proposed DLHS of “any reportable level.” EPA is also proposing to revise the DLCL from 10 µg/ft 2 , 100 µg/ft 2 and 400 µg/ft 2 for floors, window sills, and troughs to 3 µg/ft 2 , 20 µg/ft 2 , and 25 µg/ft 2 , and requesting comment on an alternative DLCL option of 5 µg/ft 2 , 40 µg/ft 2 , and 100 µg/ft 2 .

A. Dust-Lead Hazard Standards Approach

In the 2001 LBP Hazards Rule EPA discussed the dilemma the Agency faced when establishing a dust-lead hazard, especially the challenges associated with choosing “which [BLLs] i.e., “would result in adverse human health effects” (15 U.S.C. 2681(10)) given the uncertainties that existed (Ref. 6). As a result, EPA took a pragmatic approach to setting the DLHS and focused on the potential for risk reduction, cost-benefit balancing and other relevant factors, establishing the standards at 40 µg/ft 2 and 250 µg/ft 2 for floors and sills, respectively. As an aside, at that time the Agency did not establish a DLHS for troughs as it found that window sills and troughs were highly correlated and concluded that testing both surfaces would not improve a risk assessor's ability to characterize risk. Building off the precedent established in 2001, the 2019 DLHS Rule “evaluated the relationship between dust-lead levels and children's health, and . .

y. As an aside, at that time the Agency did not establish a DLHS for troughs as it found that window sills and troughs were highly correlated and concluded that testing both surfaces would not improve a risk assessor's ability to characterize risk. Building off the precedent established in 2001, the 2019 DLHS Rule “evaluated the relationship between dust-lead levels and children's health, and . . . the application of those standards in lead risk reduction programs.” In addition, when establishing the 2019 DLHS, EPA also assessed laboratory capabilities, resources for addressing LBP hazards and consistency across the Federal Government (Ref. 2). At that time EPA reasonably believed it had the discretion to set the DLHS based on both risk reduction and whether the standards were achievable, especially given the existing programs in place to reduce LBP hazards and revised the DLHS to 10 µg/ft 2 and 100 µg/ft 2 for floors and sills, respectively (Ref. 2).

Ultimately, the 2021 Court Opinion, which is discussed in Unit II.E., led EPA to undertake a major shift in its approach to residential LBP hazard control and the LBP activities program because the Opinion found that EPA did not have the authority, when setting the DLHS, to consider non-health factors ( e.g., laboratory capabilities, resources for addressing LBP hazards, consistency across the Federal Government, or cost-benefit balancing). Consistent with the 2021 Court Opinion, EPA is proposing to revise the DLHS in this rulemaking based only on health considerations. EPA intends health-only considerations in this DLHS context to refer to the effects of lead on health after exposure to dust-lead loadings, considering the statutory definition's focus on “any condition that causes exposure to lead from lead-contaminated dust . . . that would result in adverse human health effects” (15 U.S.C. 2681(10)). These health-only considerations do not include broader public health concerns (such as health trade-offs and policy impacts on public housing).

lead on health after exposure to dust-lead loadings, considering the statutory definition's focus on “any condition that causes exposure to lead from lead-contaminated dust . . . that would result in adverse human health effects” (15 U.S.C. 2681(10)). These health-only considerations do not include broader public health concerns (such as health trade-offs and policy impacts on public housing).

1. Rationale for Selecting the Proposed DLHS

EPA is proposing a non-numeric DLHS that is any reportable level of dust-lead for floors and window sills as analyzed by an NLLAP-recognized laboratory. Proposing a DLHS for floors and window sills only, is consistent with current practice and regulatory history which has not included a hazard standard specifically for troughs.

“Reportable level” is not defined in EPA's 40 CFR 745 or EPA's current guidance for NLLAP-recognized laboratories, titled Laboratory Quality System Requirements (or LQSR 3.0). EPA is proposing to define “reportable level” in the regulations to mean the lowest analyte concentration (or amount) that does not contain a “less than” qualifier and that is reported with confidence for a specific method by an NLLAP-recognized laboratory. In other words, EPA interprets “any reportable level” of dust-lead to be any level greater than or equal to the lowest value a laboratory can reliably report to a client or the regulated community ( i.e., any reportable level of dust-lead in a laboratory sample result report that does not contain a “less than” (“<”) qualifier).

Under the LQSR, an NLLAP-recognized laboratory must demonstrate it can achieve a quantitation limit equal to or less than 50% of the lowest action level for dust wipe samples (more discussion on the “action level” is found in Unit IV.A.1.c). In addition, a report of zero concentration is not permitted and laboratories must establish a method of limiting the lower reported values to a positive finite lead level that is appropriate for the technology being used

it can achieve a quantitation limit equal to or less than 50% of the lowest action level for dust wipe samples (more discussion on the “action level” is found in Unit IV.A.1.c). In addition, a report of zero concentration is not permitted and laboratories must establish a method of limiting the lower reported values to a positive finite lead level that is appropriate for the technology being used. Measured lead levels below this positive finite value must be reported with a qualifier “less than” (“<”) this positive finite value (Ref. 29).

Based on these current minimum standards for NLLAP-recognized laboratories and previous laboratory stakeholder input, EPA expects that the lowest reportable level will be equivalent to the laboratory's quantitation limit in some cases, but could be lower depending on laboratory capabilities. Ultimately, the proposed DLHS of “any reportable level” is not dependent on the DLCL or quantitation limit, but rather is based on the capabilities of individual laboratories. EPA is requesting comment on the appropriateness of this interpretation and of the proposed definition of “reportable level.”

EPA refers to this non-numeric DLHS approach as GTZ. Given the statutory language in TSCA Section 401 that defines what a “LBP hazard” is ( i.e., as conditions of LBP and lead-contaminated dust and soil that “would result in adverse human health effects”), EPA believes that it cannot set the DLHS at zero because zero does not identify a level of exposure to dust-lead loadings that would cause adverse health effects. Rather EPA believes the proposed standard of “any reportable level” is an appropriate DLHS based on dust-lead exposure related health factors only, and in accordance with the 2021 Court Opinion by taking into consideration the modeling data outlined in TSD and the current state of the science on lead exposure and children's BLL

xposure to dust-lead loadings that would cause adverse health effects. Rather EPA believes the proposed standard of “any reportable level” is an appropriate DLHS based on dust-lead exposure related health factors only, and in accordance with the 2021 Court Opinion by taking into consideration the modeling data outlined in TSD and the current state of the science on lead exposure and children's BLL. The proposed GTZ approach represents a shift in the LBP activities program to a more inclusive and protective DLHS, compared to the current 2019 and 2021 levels. If finalized as proposed, the GTZ approach will be inclusive of any reportable level of dust-lead and will not distinguish between severe, less severe, or negligible risks.

As discussed further in Unit IV.A.2 Other DLHS Options EPA Considered, two other approaches were also considered for revising the DLHS, including a numeric standard based entirely on the modeling data laid out in the TSD (summarized in TSD Table 2-2), and an approach that would use the background dust-lead levels of housing built in or after 1978 (called post-1977 background). EPA seeks comment on its proposed and potential alternative approaches to updating the DLHS.

a. GTZ Rationale: Modeled Discussion

The GTZ approach is primarily supported by the modeling results provided in the TSD and discussed further in Unit IV.A.3. In the TSD (which is introduced in Unit III) EPA estimated BLL and related changes in IQ (a measure of cognitive function) in young children. The results show that as dust-lead levels in housing decrease below the current standard ( i.e., 10 µg/ft 2 and 100 µg/ft 2 for floors and window sills), so do children's BLL and IQ decrement from lead exposure. When modeling GTZ, EPA used estimated dust-lead loadings ranging from 0.7 to 2.2 µg/ft 2 for floors and 0.8 to 4.4 µg/ft 2 for window sills

easure of cognitive function) in young children. The results show that as dust-lead levels in housing decrease below the current standard ( i.e., 10 µg/ft 2 and 100 µg/ft 2 for floors and window sills), so do children's BLL and IQ decrement from lead exposure. When modeling GTZ, EPA used estimated dust-lead loadings ranging from 0.7 to 2.2 µg/ft 2 for floors and 0.8 to 4.4 µg/ft 2 for window sills. These are assumed values for a GTZ DLHS paired with the proposed or alternative DLCL, and account for the lower reporting thresholds that EPA estimates laboratories will realistically attain under this proposal. EPA collected information on real-world laboratory reporting limits from stakeholder outreach conversations as well as

b. GTZ Rationale: No Threshold Has Been Identified

According to TSCA Title IV, the DLHS should identify the level of dust-lead exposure that “would result in adverse human health effects” (15 U.S.C. 2681(10)). GTZ is a more protective approach compared to the current regulatory landscape and all the options that were considered for this rulemaking (except post-77 background). GTZ also acknowledges that the current state of scientific evidence does not identify a BLL threshold below which there is no association of adverse effects on children's cognition. Depending on the exposure and other factors, the effects on IQ associated with childhood lead exposure may persist into adolescence and adulthood (Refs. 4 and 8). EPA also favored such an approach for the DLHS under TSCA Title IV in part because a more protective approach to DLHS, such as GTZ, aligns with the Congressional purpose for disclosure elsewhere under Title X (notably, as implemented in the Lead Disclosure Rule) and because Congress used the word “hazard” in the “lead-based paint hazard” term, even though the definition uses more risk-like language by introducing consideration of the level of exposure that would result in adverse health effects

e approach to DLHS, such as GTZ, aligns with the Congressional purpose for disclosure elsewhere under Title X (notably, as implemented in the Lead Disclosure Rule) and because Congress used the word “hazard” in the “lead-based paint hazard” term, even though the definition uses more risk-like language by introducing consideration of the level of exposure that would result in adverse health effects.

EPA's 2013 Lead ISA stated that harmful effects on children's cognition as measured by IQ were observed in groups with mean BLLs as low as 2 µg/dL, and further that despite there being some uncertainty in epidemiological studies on lead exposure and BLLs (especially for older children and adults) that “A threshold for cognitive function decrements is not discernable from the available evidence ( i.e., examination of early childhood blood Pb or concurrent blood Pb in the range of <1 to 10 μg/dL).” (Ref. 4)). This statement was based on a synthesis of the extensive literature examining the relationship between BLL and cognitive function, including a landmark pooled cohort study meta-analysis by Lanphear et al. (Refs. 40 and 41), the results of which have been confirmed by repeated re-analysis (Refs. 42 and 43). While the 2013 ISA went on to state that “the current evidence does not preclude the possibility of a threshold for neurodevelopmental effects in children existing with lower blood levels than those currently examined”, the Federal Lead Action Plan articulated the U.S. Government position that “no safe blood lead level in children has been identified.” (Ref. 9). Further, the analysis that supports this rule examined the 95th percentile of children's modeled BLLs and the associated IQ losses (Ref. 16), which for all options considered is at or above the group mean BLLs for which IQ loss is observed in the literature examined in the ISA (Ref. 4 and 16)

ed the U.S. Government position that “no safe blood lead level in children has been identified.” (Ref. 9). Further, the analysis that supports this rule examined the 95th percentile of children's modeled BLLs and the associated IQ losses (Ref. 16), which for all options considered is at or above the group mean BLLs for which IQ loss is observed in the literature examined in the ISA (Ref. 4 and 16).

EPA understands the limitations of the epidemiological analyses, the lack of scientific studies evaluating low BLLs and acknowledges that a threshold could exist that is currently unidentified; but ultimately in its assessment of the available scientific research findings in the 2013 ISA for lead, the Agency observed that there is no evidence of a threshold below which there are no harmful health effects from lead exposure. EPA continues to acknowledge the aforementioned uncertainties and notes that science is constantly evolving and, as additional data become available ( e.g., exposure and health impacts), then EPA may undertake a new rulemaking to propose changing the standards in the future to reflect any new data or information about an acceptable threshold of effects on cognition in children.

Additionally, the Centers for Disease Control and Prevention (CDC) acknowledges that “[s]cientific evidence suggests that there is no known safe [BLL], because even small amounts of lead can be harmful to a child's developing brain” (Ref. 44). When the original DLHS and DLCL were proposed and finalized in 1998 and 2001 the CDC had set a “level of concern” for children's BLL at ≥10 µg/dL (Refs. 45 and 46). In 1991, when that level was established as a level that should prompt public health actions, the CDC concurrently recognized that a BLL of 10 µg/dL did not define a threshold for the harmful effects of lead (Ref. 45). One goal for the level was that “all lead poisoning prevention activities should be to reduce children's BLLs below 10 µg/dL” (Ref. 45)

hildren's BLL at ≥10 µg/dL (Refs. 45 and 46). In 1991, when that level was established as a level that should prompt public health actions, the CDC concurrently recognized that a BLL of 10 µg/dL did not define a threshold for the harmful effects of lead (Ref. 45). One goal for the level was that “all lead poisoning prevention activities should be to reduce children's BLLs below 10 µg/dL” (Ref. 45). Accordingly, in the 1998 proposal EPA stated that, “[a]lthough the scientific community has not been able to identify a threshold of exposure below which adverse health effects do not occur, the evidence of health effects below 10 µg/dL is not sufficiently strong to warrant concern” (Ref. 47). In the final rule in 2001, EPA determined the lowest candidate DLHS by using a 1 to 5% probability of an individual child developing a BLL of 10 μg/dL (Ref. 6).

In the 2019 DLHS Rule, EPA recognized that “[a]lthough health risks to young children decrease with decreasing dust-lead levels, no non-zero lead level, including background levels, can be shown to eliminate health risk entirely.” At that time, EPA also recognized the CDC's 2012 decision to discontinue its use of a 10 µg/dL blood lead “level of concern” and to introduce a population-based blood lead reference value (BLRV) to identify children exposed to more lead than most other children in the United States (Ref. 48). The BLRV represents the 97.5th percentile of the U.S. population BLL distribution in children ages 1 to 5 from the National Health and Nutrition Examination Surveys (NHANES). This means that by definition 2.5 percent of children ages 1 to 5 in the NHANES survey have a BLL greater than the BLRV. This metric was established in part because “no safe blood lead level in children ha[d] been identified,” (Ref. 48). In 2012 the BLRV was 5 µg/dL, based on young children's BLL in the 2007-2010 NHANES, and in 2021 it was lowered to 3.5 µg/dL based on the children's lower BLLs observed in the 2015-2018 NHANES (Ref. 46)

t of children ages 1 to 5 in the NHANES survey have a BLL greater than the BLRV. This metric was established in part because “no safe blood lead level in children ha[d] been identified,” (Ref. 48). In 2012 the BLRV was 5 µg/dL, based on young children's BLL in the 2007-2010 NHANES, and in 2021 it was lowered to 3.5 µg/dL based on the children's lower BLLs observed in the 2015-2018 NHANES (Ref. 46). The BLRV is not based on a health endpoint, but rather is a statistical point in the distribution of children's BLLs in the U.S. used as a screening tool to identify children who have higher levels of lead in their blood compared with most children.

Establishing a health-based only standard for dust-lead hazard, as well as clearance levels that consider other factors ( i.e., take into account reliability, effectiveness, and safety), is similar to EPA's implementation of some other programs governing lead exposure. For example, under the Safe Drinking Water Act (SDWA), EPA is required to establish a maximum contaminant level goal (MCLG) at a level at which, in the Administrator's judgement, “no known or anticipated adverse effects on the health of persons occur and which allows an adequate margin of safety.” Section 1412(b)(4). EPA established a health-based MCLG of zero for lead in drinking water. National Primary Drinking Water Regulations include either an enforceable maximum contaminant level (MCL) or treatment technique requirements, EPA can set a treatment technique requirement in lieu

Because of the 2021 Court Opinion remanding the DLHS for reconsideration based only on health factors, the results of the analysis in the TSD, and the lack of a discernible threshold in the evidence for the association of blood lead with harmful effects on cognition in young children, EPA proposes to change the DLHS to any reportable level of lead analyzed by an NLLAP-recognized laboratory.

c. LQSR Action Level

Given that GTZ is a non-numeric value, if finalized as proposed, the DLCL, rather than the DLHS, would become the “action level” as described in the Laboratory Quality System Requirements (LQSR 3.0), as well as for when a risk assessor would recommend an abatement (see Unit IV.D. for more information on EPA's proposed change to the definition of abatement). According to the current LQSR, NLLAP-recognized laboratories that analyze dust wipe samples for lead must show that they can achieve a quantitation limit “equal to or less than . . . 50% of the lowest action level [ i.e., regulatory limit] for dust wipe samples” (Ref. 29). The quantitation limit must also be “at least 2 times but no greater than 10 times the method detection limit” (Ref. 29). Therefore, due to the non-numeric nature of the proposed DLHS of “any reportable level,” these current testing requirements will rely on the numerical DLCL to establish the quantitation limit that any laboratory (that wishes to maintain or obtain NLLAP recognition) must be able to demonstrate. Note however, that the proposed DLHS of “any reportable level” is still considered distinct from the DLCL and the quantitation limit.

2. Other DLHS Approaches EPA Considered

DLCL and the quantitation limit.

2. Other DLHS Approaches EPA Considered

EPA considered two other approaches for revising the DLHS: a numeric standard based on the probability of exceedance of one or more IQ or BLL metrics as determined by the Agency, and an approach that would use the background dust-lead levels of housing built in 1978 and beyond as the DLHS (known as “post-1977 background”). The three approaches ( i.e., GTZ, numeric standard, and post-1977 background) take different analytical paths to revising the DLHS based only on health considerations. EPA is proposing the GTZ approach, given the discussion laid out in Unit IV.A.1. but welcomes comment on the other two approaches outlined in both the preamble and in the TSD (Ref. 16).

a. Numeric Standard Approach

In addition to the GTZ approach, EPA also explored a “numeric standard” approach, meaning that the Agency would propose a numerical DLHS with a rationale based solely on the interpretation of the TSD results. To do so, the Agency would need to establish a health or exposure metric of interest ( i.e., target BLL or IQ change) that would be acceptably protective of human health. Estimated BLL and IQ decrements in children exposed to hypothetical dust-lead loading values are included in the TSD for every DLHS candidate considered for all three approaches ( i.e., GTZ, numeric standard and post-1977 background), as well as the primary and alternative DLCL options. These values are estimated to help EPA analyze the impacts of this proposed rulemaking on the health ( i.e., IQ decrement) and dust-lead exposure of the subpopulation in question ( i.e., young children in pre-1978 buildings and COFs) and to inform a costs and benefits analysis in the EA.

lth ( i.e., IQ decrement) and dust-lead exposure of the subpopulation in question ( i.e., young children in pre-1978 buildings and COFs) and to inform a costs and benefits analysis in the EA.

In 2001 and 2019, EPA expressed the challenges of meeting the statutory criterion for defining an LBP hazard (15 U.S.C. 2681(10)) because it requires EPA to choose a cutoff for when unacceptable risk exists. EPA noted in 2001, even if the science and environmental-lead prevalence data were perfect, there would likely be no agreement on the level, or certainty, of risk that is envisioned in the phrase “would result in adverse human health effects.” Thus, EPA explained that it “would not be appropriate to base a [LBP] hazard standard on any specific probability of exceeding any specific [BLL].” (Refs. 2 and 6). EPA continues to agree with the challenges highlighted in 2001 and 2019.

When choosing health or exposure metrics to evaluate the DLHS approaches based on the TSD results, the Agency has considered three factors: (1) the CDC's BLRV (which is a not a health-based end point but rather is a statistical measure of relative exposure), (2) responsiveness to feedback received previously from various scientific bodies, and (3) Agency precedent. The TSD considers BLL and IQ changes in two ways: relative to aggregate/total lead exposure (which includes exposure from other media: soil, diet, water, and air in addition to dust) and relative to incremental/dust-only lead exposure (Ref. 16). For example, in 2001 the lowest DLHS candidate was identified by using a 1 to 5% probability of an individual child developing a BLL of 10 μg/dL (Ref. 6), which represented total BLL, inclusive of exposure to lead through other media.

ng a BLL of 10 μg/dL (Ref. 6), which represented total BLL, inclusive of exposure to lead through other media.

In the TSD analyses for this proposal, EPA compared BLL in young children, with an emphasis on 2-year-old children because this is the age of greatest modeled exposure, from aggregate or total exposure from all media ( i.e., dust, soil, diet, water, and air) to the CDC BLRV of 3.5 μg/dL. This BLL value is not-health based and does not represent a toxicity threshold (and is subject to change over time, since the CDC BLRV changes as the BLLs in the population change); however, CDC explains that it can still be used as a tool to “ (1) help determine whether medical or environmental follow-up actions should be initiated for an individual child and (2) prioritize communities with the most need for primary prevention of exposure and evaluate the effectiveness of prevention efforts” (Ref. 46). Importantly, even at zero dust-lead, children are already estimated to have a 5.7% probability of exceeding the BLRV given the impact of background lead exposures from other media ( e.g., soil, diet, water, and air) (Ref. 16).

Table 1—Percent Exceedance Values for Zero, Age: 2 Yr Old (30 Months) Approach Floor (µg/ft²) Sill (µg/ft²) Probability Total BLL >3.5 µg/dL Total BLL >5 µg/dL Dust only BLL >1 µg/dL Dust only BLL >2.5 µg/dL Zero 1 0 0 5.7% 2.2% 0.0% 0.0% 1 The exceedance values for zero dust-lead are provided for comparison with the DLHS candidates; it is not a candidate value. In 2011, EPA's Scientific Advisory Board (SAB) and in 2012 the Children's Health Protection Advisory Committee (CHPAC) both expressed support for an incremental BLL approach that focuses on dust-lead exposure only

g/dL Dust only BLL >2.5 µg/dL Zero 1 0 0 5.7% 2.2% 0.0% 0.0% 1 The exceedance values for zero dust-lead are provided for comparison with the DLHS candidates; it is not a candidate value. In 2011, EPA's Scientific Advisory Board (SAB) and in 2012 the Children's Health Protection Advisory Committee (CHPAC) both expressed support for an incremental BLL approach that focuses on dust-lead exposure only. In 2011 SAB reviewed EPA's Approach for Developing Lead Dust Hazard Standards for Residences (November 2010 Draft) and Approach for Developing Lead Dust Hazard Standards for Public and Commercial Buildings (November 2010 Draft) and provided feedback that there are several key advantages to the incremental approach ( e.g., reducing uncertainty from estimating exposures from other media) and provided that a change in BLL “of 1 or 2 μg/dL at the 90th percentile” could be an example of a target risk level. Similarly, CHPAC expressed support for using an incremental approach and preferred levels such that an adverse change in BLL is “no greater than 1 or 2.5 µg/dL” (Ref. 49).

As a result, EPA also estimated what dust-lead levels (considering only the dust-lead component in the multi-media exposure modeling) would result in incremental BLL change ranging between 1 and 2.5 μg/dL based on exposure assumptions described in the TSD (Ref. 16).

For this reconsideration rulemaking the Agency considered the estimated total/aggregate IQ change ( i.e., the estimated total or aggregate IQ change from modeled BLL including all modeled sources of lead exposure) at age six and compared it to a threshold of 1 to 2 points. IQ changes due to background exposures to lead in other media ( e.g., soil, diet, water, and air) are estimated to already have a 48.7% probability to exceed 2 points for children in target housing without also considering additional dust-lead exposure (Ref. 16)

te IQ change from modeled BLL including all modeled sources of lead exposure) at age six and compared it to a threshold of 1 to 2 points. IQ changes due to background exposures to lead in other media ( e.g., soil, diet, water, and air) are estimated to already have a 48.7% probability to exceed 2 points for children in target housing without also considering additional dust-lead exposure (Ref. 16).

Table 2—Percent Exceedance Values for Zero, Age: 6 Yr Old (72 Months) Approach Floor (μg/ft 2 ) Sill (μg/ft 2 ) Probability Total IQ >1pt Total IQ >2pt Dust only IQ >1pt Dust only IQ >2pt Zero 1 0 0 88.9% 48.7% 0.0% 0.0% 1 The exceedance values for zero dust-lead are provided for comparison with the DLHS candidates; it is not a candidate value. In addition to total/aggregate IQ change, EPA determined BLLs that were estimated to result in an incremental loss of 1 to 2 IQ points from exposure to only dust-lead ( i.e., exclusive of lead in other media such as soil, diet, water, and air). This metric is explicitly health-based, in that it is an estimated health effect. There is EPA precedence for using the metric of an incremental change in IQ with a range of values of 1 to 2 points to inform national standards decisions. This includes the 2008 and 2016 decisions on the primary national ambient air quality standard (NAAQS) for lead, which was informed by consideration of air-related IQ decrement estimates based on an evidence-based framework, with a focus on the at-risk subpopulation of children living near sources who are likely to be most highly exposed (Ref. 50). In their review of various technical documents supporting both the 2008 and 2016 NAAQS reviews, the Clean Air Scientific Advisory Committee (CASAC) supported using an incremental 1 to 2 point IQ decrement approach for consideration during development of the air standard (Refs. 50 and 51)

n the at-risk subpopulation of children living near sources who are likely to be most highly exposed (Ref. 50). In their review of various technical documents supporting both the 2008 and 2016 NAAQS reviews, the Clean Air Scientific Advisory Committee (CASAC) supported using an incremental 1 to 2 point IQ decrement approach for consideration during development of the air standard (Refs. 50 and 51).

As reported in the TSD, EPA evaluated several numeric DLHS candidates that the Agency thought were appropriate given the health and exposure metrics of interest, and the uncertainty of the model at low loading values. The numeric DLHS candidates were 1/10 μg/ft 2 ( i.e., 1 μg/ft 2 for floors and 10 μg/ft 2 for sills), 2/20 μg/ft 2 , 3/30 μg/ft 2 , and 5/40 μg/ft 2 and those values were compared to the specified BLL and IQ metrics to estimate the probability of exceeding the BLL or IQ targets. For example, a 2-year-old living in pre-1978 housing exposed to 3 μg/ft 2 on floors and 30 μg/ft 2 on window sills would have a 4.8% probability of exceeding, for example, 5 total µg/dL BLL. Under this numeric standard approach, EPA would plan to use the threshold of 5% probability of exceedance for a child from the sub-population of interest ( i.e., young children living in pre-1978 housing and COFs). This is similar to the 1 to 5% probability that was used in 2001 for the lowest DLHS candidate (Ref. 6).

Due to the aforementioned complexities with identifying a cutoff of risk or specific IQ/BLL metrics of interest that would be acceptable for purposes of setting the DLHS, as well as the reasons for favoring GTZ, EPA is not proposing the numeric standard approach for the DLHS as the Agency's preferred option. For specific discussion on the modeled numeric DLHS candidates and IQ/BLL metrics, see Unit IV.A.3. EPA welcomes comment on this numeric standard approach including the IQ/BLL metrics under consideration ( i.e., the target values of interest) and the use of a 5% probability of exceedance.

ing GTZ, EPA is not proposing the numeric standard approach for the DLHS as the Agency's preferred option. For specific discussion on the modeled numeric DLHS candidates and IQ/BLL metrics, see Unit IV.A.3. EPA welcomes comment on this numeric standard approach including the IQ/BLL metrics under consideration ( i.e., the target values of interest) and the use of a 5% probability of exceedance.

b. Post-1977 Background Approach

EPA also considered an approach to revise the DLHS that would align target housing dust-lead levels with dust-lead levels in housing built after lead-based paint was banned. This approach would result in lowering the DLHS to the dust-lead background levels of housing built after 1977 (known as “post-1977 background”), which are presumably not from LBP. In 1978, the CPSC banned lead in paint and similar surface-coating materials for consumer use in excess of 0.06% and revised the level in 2009 to 0.009% following the Consumer Product Safety Improvement Act of

Post-1977 background dust-lead values were calculated from a weighted geometric mean of the dust-lead loadings from the American Healthy Homes Survey II and were found to be 0.2 µg/ft 2 for floors and 0.8 µg/ft 2 for window sills (Refs. 14 and 52). Setting the DLHS at the post-1977 background dust-lead levels would allow EPA to focus on dust-lead hazards above what is expected in housing without LBP ( i.e., after CPSC established a maximum level of lead in paint for consumer products, including home paints). Establishing DLHS for target housing and COFs in this way, using post-1977 background dust-lead levels, would address disparities in the dust-lead levels that children in target housing may be exposed to and the corresponding disparate health risks. This approach would also align with the focus of Title X on lead hazards in housing constructed before 1978

consumer products, including home paints). Establishing DLHS for target housing and COFs in this way, using post-1977 background dust-lead levels, would address disparities in the dust-lead levels that children in target housing may be exposed to and the corresponding disparate health risks. This approach would also align with the focus of Title X on lead hazards in housing constructed before 1978. Using this approach, DLHS would be established at 0.2 μg/ft 2 for floors and 0.8 μg/ft 2 for window sills as the dust-lead levels that would result in adverse human health effects. However, there are questions about whether the post-1977 background approach would as directly address the 2021 Court Opinion as the GTZ approach. Due to those concerns and the reasons for favoring GTZ, EPA is not proposing the post-1977 background approach for the DLHS as the Agency's preferred option.

As statistical points in a distribution of environmental data, the calculation of the average background value is highly influenced by the way in which data/measurements below the analytical detection limit are treated. Further discussion on deriving these candidates can be found in the TSD Section 2.3. The TSD models the health and exposure outcomes based on these candidate DLHS of 0.2 μg/ft 2 for floors and 0.8 μg/ft 2 for window sills, as described in Unit IV.A.3. EPA welcomes comment on this background approach, and its appropriateness given the description above, 2021 Court Opinion and the statutory authority.

3. Modeled Results for All Three DLHS Approaches

The TSD that accompanies this proposal evaluated the DLHS candidates of all three approaches ( i.e., GTZ, numeric standard, and post-1977 background)

for window sills, as described in Unit IV.A.3. EPA welcomes comment on this background approach, and its appropriateness given the description above, 2021 Court Opinion and the statutory authority.

3. Modeled Results for All Three DLHS Approaches

The TSD that accompanies this proposal evaluated the DLHS candidates of all three approaches ( i.e., GTZ, numeric standard, and post-1977 background). Estimates for BLLs of children exposed to the DLHS dust-lead loadings were evaluated for children at each age up to age six, including age two (generally, age two is the age of greatest modeled exposure), and lead-related reduction in IQ at age six was estimated from the lifetime average BLL (average of BLLs across the period prior to age six). This approach is consistent with the study from which the BLL concentration-IQ response function was drawn. This study related IQ quantified at about six years of age to each child's lifetime average BLLs (based on blood Pb measurements taken from six months up to age of the IQ test (Refs. 40 and 41). In the following discussion, both the model results for two-year BLL and the estimates of IQ change at six-years, are represented, referring to them as the results for “young children” for brevity. EPA considered numerous dust-lead loadings, including: 0.7/0.8 μg/ft 2 , ( i.e., 0.7 μg/ft 2 for floors and 0.8 μg/ft 2 for window sills) which is the GTZ option partnered with the primary DLCL option (3/20/25 μg/ft 2 for floors, window sills, and window troughs respectively) and 2.2/4.4 μg/ft 2 , which is the GTZ partnered with the alternative DLCL option (5/40/100 μg/ft 2 ). Other modeled dust-lead loadings are 0.2/0.8 μg/ft 2 , which is the post-1977 background dust-lead level, 1/10 μg/ft 2 , 2/20 μg/ft 2 , 3/30 μg/ft 2 , 5/40 μg/ft 2 , and 10/100 μg/ft 2 , which is the 2019 DLHS. Zero was also provided for comparison purposes with the DLHS candidates and is not itself a candidate value

which is the GTZ partnered with the alternative DLCL option (5/40/100 μg/ft 2 ). Other modeled dust-lead loadings are 0.2/0.8 μg/ft 2 , which is the post-1977 background dust-lead level, 1/10 μg/ft 2 , 2/20 μg/ft 2 , 3/30 μg/ft 2 , 5/40 μg/ft 2 , and 10/100 μg/ft 2 , which is the 2019 DLHS. Zero was also provided for comparison purposes with the DLHS candidates and is not itself a candidate value. More information on the TSD and the health/exposure metrics ( i.e., IQ and BLL decrements) that were analyzed can be found in Unit III. and Unit IV.A.2.a.

DLHS candidates associated with GTZ, post-1977 background, and the numeric standard (1/10 μg/ft 2 ) approaches are associated with the lowest BLLs when compared to the other numeric DLHS candidates (2/20 μg/ft 2 , 3/30 μg/ft 2 and 5/40 μg/ft 2 and the current DLHS of 10/100 μg/ft 2 for floors and window sills). The TSD modeling results for young children exposed to dust-lead associated with the loading candidates from the GTZ approach (which range from 0.7 to 2.2 µg/ft 2 for floors and 0.8 to 4.4 µg/ft 2 for window sills depending on which DLCL it is coupled with, see Unit IV.A.1.a. for more information) show that young children would have a 0.0 to 10.6% probability of exceeding an incremental BLL of 1 to 2.5 μg/dL (Tables 7-2 and 7-3 in the TSD). However, the results for GTZ partnered with the primary DLCL option (0.7/0.8 μg/ft 2 ), and post-1977 background (0.2/0.8 μg/ft 2 ) are the only two DLHS candidates that keep both the percentage of exceedance of incremental BLL of 1 to 2.5 μg/dL below 5% probability (which is the threshold of interest EPA identified).

ce of incremental BLL of 1 to 2.5 μg/dL below 5% probability (which is the threshold of interest EPA identified).

When comparing the three DLHS approaches to total BLL, the modeling includes exposure from other media such as soil, diet, water, and air. Importantly, even at zero dust-lead, children would still have a 5.7% probability of exceeding the BLRV given the impact of these other exposures. Thus, none of the considered DLHS candidates resulted in less than 5% probability of exposed children's BLL exceeding the CDC BLRV. However, the TSD modeling results did show that for young children exposed to dust-lead loadings using the GTZ approach, the post-1977 background approach or the numeric DLHS candidate of 1/10 μg/ft 2 would have approximately a 7.3 to 9.1% probability of exceeding a total BLL of 3.5 μg/dL, the CDC's BLRV. This is lower than the 10.3 to 13.9% probability when exposed to other numeric DLHS candidates (2/20 μg/ft 2 , 3/30 μg/ft 2 and 5/40 μg/ft 2 for floors and window sills) and the 18.0% probability when exposed to the current DLHS of 10 μg/ft 2 for floors and 100 μg/ft 2 for window sills. Therefore, while no DLHS option results in a less than 5.7% probability of exposed children's BLL exceeding the CDC BLRV given their likely exposures to other sources of lead, the options with the lowest levels (GTZ, post-1977 background, and 1/10 μg/ft 2 ) result in exposed children experiencing about a two to three times less likelihood of exceeding the CDC BLRV compared to the current DLHS

lls. Therefore, while no DLHS option results in a less than 5.7% probability of exposed children's BLL exceeding the CDC BLRV given their likely exposures to other sources of lead, the options with the lowest levels (GTZ, post-1977 background, and 1/10 μg/ft 2 ) result in exposed children experiencing about a two to three times less likelihood of exceeding the CDC BLRV compared to the current DLHS.

Table 3—Percent Exceedance Values for DLHS Candidates, Age: 2 Yr Old (30 Months) Approach Floor (μg/ft 2 ) Sill (μg/ft 2 ) Probability Total BLL >3.5 μg/dL (%) Total BLL >5 μg/dL (%) Dust only BLL >1 μg/dL (%) Dust only BLL >2.5 μg/dL (%) Zero 1 0 0 5.7 2.2 0.0 0.0 Post-1977 Background 0.2 0.8 7.3 2.8 1.0 0.0 GTZ With 3/20 DLCL 0.7 0.8 8.2 3.0 3.7 0.1 Numeric 1 10 9.1 3.3 6.6 0.5 GTZ With 5/40 DLCL 2.2 4.4 10.1 3.9 10.6 1.0 Numeric 2 20 10.3 4.1 12.5 1.2 Numeric 3 30 11.8 4.8 17.2 2.0 Numeric 5 40 13.9 5.5 23.0 3.2 Current Standard 10 100 18.0 7.5 36.7 6.5 1 The exceedance values for zero dust-lead are provided for comparison with the DLHS candidates; it is not a candidate value. DLHS candidates associated with GTZ and post-1977 background are also estimated to be associated with the lowest IQ decrements when compared to the other DLHS candidates (GTZ partnered with the alternative DLCL, 1/10 μg/ft 2 , 2/20 μg/ft 2 , 3/30 μg/ft 2 and 5/40 μg/ft 2 , and the current DLHS of 10/100 μg/ft 2 for floors and window sills). GTZ partnered with the primary DLCL option (0.7/0.8 μg/ft 2 ), and post-1977 background (0.2/0.8 μg/ft 2 ) are the only two DLHS candidates estimated to have a 0.6 to 2.5% probability of exceeding 2 points of incremental IQ loss from dust-exposure, keeping the percentage of exceedance of 2 points of IQ loss below 5% probability

, and the current DLHS of 10/100 μg/ft 2 for floors and window sills). GTZ partnered with the primary DLCL option (0.7/0.8 μg/ft 2 ), and post-1977 background (0.2/0.8 μg/ft 2 ) are the only two DLHS candidates estimated to have a 0.6 to 2.5% probability of exceeding 2 points of incremental IQ loss from dust-exposure, keeping the percentage of exceedance of 2 points of IQ loss below 5% probability.

Table 4—Percent Exceedance Values for DLHS Candidates, Age: 6 yr old (72 months) Approach Floor (μg/ft 2 ) Sill (μg/ft 2 ) Probability Total IQ 1pt (%) Total IQ >2pt (%) Dust only IQ >1pt (%) Dust only IQ >2pt (%) Zero 1 0 0 88.9 48.7 0.0 0.0 Post-1977 Background 0.2 0.8 94.7 63.1 6.2 0.6 GTZ With 3/20 DLCL 0.7 0.8 96.4 70.4 18.5 2.5 Numeric 1 10 97.0 74.5 30.2 5.2 GTZ With 5/40 DLCL 2.2 4.4 97.7 78.5 40.7 9.0 Numeric 2 20 97.9 80.0 44.6 11.0 Numeric 3 30 98.5 82.3 53.6 16.0 Numeric 5 40 98.8 85.1 62.7 22.4 Current Standard 10 100 99.4 90.3 75.8 37.9 1 The exceedance values for zero dust-lead are provided for comparison with the DLHS candidates; it is not a candidate value. B. Dust-Lead Clearance Levels Approach

TSCA Title IV granted EPA the authority to regulate LBP activities, and to take into account reliability, effectiveness, and safety (15 U.S.C. 2682(a)(1)) when setting the DLCL. While considering those three criteria, the 2001 LBP Hazards Rule modified the work practice standards to include DLCL, which “are used to evaluate the effectiveness of cleaning following an abatement” (Ref. 6). In both the 2001 LBP Hazards Rule and the 2021 DLCL Rule, the DLCL were finalized as the same value as the DLHS for floors and window sills. When originally established, EPA considered the DLCL in the broader context of Title X, and selected DLCL that were compatible with a “workable framework for lead-based paint hazard evaluation and reduction.” EPA chose DLCL that were consistent with the DLHS in part to ensure they were “as easy as possible to understand and implement” (Ref. 47)

e same value as the DLHS for floors and window sills. When originally established, EPA considered the DLCL in the broader context of Title X, and selected DLCL that were compatible with a “workable framework for lead-based paint hazard evaluation and reduction.” EPA chose DLCL that were consistent with the DLHS in part to ensure they were “as easy as possible to understand and implement” (Ref. 47). At that time EPA established the DLCL and the DLHS at 40 μg/ft 2 and 250 μg/ft 2 for floors and window sills, with a separate DLCL of 400 μg/ft 2 for troughs.

In 2021 the DLCL set by EPA continued to mirror the DLHS as it had done historically, as the Agency explained that it wanted to update the DLCL to achievable levels that would demonstrate elimination of dust-lead hazards under the 2019 DLHS of 10 μg/ft 2 for floors and 100 μg/ft 2 for window sills. The 2021 updates to the DLCL restored consistency between the DLCL and DLHS, which had been lowered in 2019 without a corresponding amendment to the DLCL. Previous public comments received on the 2018 DLHS proposal and 2020 DLCL proposal favored lowering the DLCL to be consistent with the DLHS (Refs. 53 and 54). As a result, in 2021 EPA finalized DLCL of 10 μg/ft 2 for floors and 100 μg/ft 2 for window sills (the same levels as the DLHS), and “EPA considered the achievability of these levels, how the lower dust-lead loadings can be reliably detected by laboratories, the effectiveness of these levels, and consistency with the revised 2019 standards and across the Federal Government” (Ref. 3).

standards and across the Federal Government” (Ref. 3).

The 2021 Court Opinion affirmed that “TSCA [Title] IV gives the EPA latitude to consider `reliability, effectiveness, and safety'” when promulgating regulations “[w]ith respect to implementation, including abatement.” A Cmty. Voice, 997 F.3d at 995 (Ref. 11). This would include the DLCL as they represent part of post-abatement work practices. The Court continued by emphasizing that this gives EPA more discretion when setting the DLCL because they are relevant to the implementation of remedial measures, rather than the identification of a hazard ( i.e., DLHS). The Court analogized this dichotomy to other environmental statutory schemes (see also Unit IV.A.1.b. for EPA's discussion of the

In accordance with the 2021 Court Opinion, EPA is proposing to revise the DLCL in the same proceeding as the reconsideration of the 2019 DLHS, and given the Court's direction for how to revise the DLHS and DLCL, EPA is proposing clearance levels that are decoupled from the DLHS (see Unit I.B and C. for more background on decoupling). EPA evaluated the 2021 DLCL in accordance with the statute and is proposing to revise the DLCL from 10 μg/ft 2 , 100 μg/ft 2 and 400 μg/ft 2 for floors, window sills, and troughs, respectively, to 3 μg/ft 2 , 20 μg/ft 2 , and 25 μg/ft 2 . EPA is proposing to revise the DLCL in order to reduce exposure to dust-lead beyond the 2021 levels. Additionally, New York City (NYC) has lowered their clearance levels since the 2021 DLCL final rule, which shows that levels below EPA's 2021 DLCL are achievable. Discussion on NYC's clearance levels can be found in Unit IV.B.2.d. Accordingly, EPA is also requesting comment on an alternative DLCL of 5 μg/ft 2 , 40 μg/ft 2 , and 100 μg/ft 2 , as well as whether another DLCL is appropriate given reliability, effectiveness and safety and why, see Unit VII.

levels since the 2021 DLCL final rule, which shows that levels below EPA's 2021 DLCL are achievable. Discussion on NYC's clearance levels can be found in Unit IV.B.2.d. Accordingly, EPA is also requesting comment on an alternative DLCL of 5 μg/ft 2 , 40 μg/ft 2 , and 100 μg/ft 2 , as well as whether another DLCL is appropriate given reliability, effectiveness and safety and why, see Unit VII.

1. Selecting the Proposed DLCL

EPA is proposing to revise the DLCL given the statutory criteria of reliability, effectiveness, and safety, based on consideration of HUD's Lead Hazard Control Clearance Survey (LHCCS), the potential for risk reduction by lowering exposure to dust-lead, and an evaluation of laboratory capabilities and capacity.

a. Lead Hazard Control Clearance Survey

EPA collaborated with HUD to develop the 2015 LHCCS to examine whether HUD's Office of Lead Hazard Control and Healthy Homes (OLHCHH) Lead Hazard Control (LHC) grantees could achieve DLCL below the standards at that time (40 μg/ft 2 , 250 μg/ft 2 and 400 μg/ft 2 for floors, window sills and troughs, respectively). LHC work performed by the grantees must be conducted by LBP certified individuals. Since most of the LHC grantees use commercial firms in their area, HUD OLHCHH believes that the grantees are conducting a large percentage of these activities and are therefore representative of the regulated community.

At that time, 98 LHC grantees completed the survey, giving HUD information from housing units in which lead hazard control activities took place from 2010 through 2012, for a total dataset of 1,552 housing units including 7,211 floor samples and 4,893 window sill samples (Ref. 55). The data were analyzed to determine the percentage of samples cleared at or below specific values. Numerical modeling was performed to estimate loadings that fell below laboratory detection limits. For more information on how that analysis was conducted please see Appendix D of the EA (Ref. 14)

al dataset of 1,552 housing units including 7,211 floor samples and 4,893 window sill samples (Ref. 55). The data were analyzed to determine the percentage of samples cleared at or below specific values. Numerical modeling was performed to estimate loadings that fell below laboratory detection limits. For more information on how that analysis was conducted please see Appendix D of the EA (Ref. 14). Since the 2015 LHCCS report was published, to the Agency's knowledge, there has not been any data or source of information of this magnitude in terms of DLCL samples alongside the details of the clearance process, including the number of tests performed (with results) and the type of additional work or cleaning performed. EPA found this 2015 LHCCS report still relevant and recent enough to provide meaningful input to inform this reconsideration rulemaking.

In terms of the primary DLCL option EPA is proposing, 64% of the 2010 to 2012 samples showed dust-lead levels at or below 3 μg/ft 2 for floors, 64% were at or below 20 μg/ft 2 for window sills, and 64% were at or below 25 μg/ft 2 for window troughs. As a result, approximately 64% of samples from the LHCCS data had dust-lead levels at or below the primary DLCL option of 3 μg/ft 2 for floors, 20 μg/ft 2 for window sills and 25 μg/ft 2 for troughs, which EPA believes is achievable, especially since the survey respondents were only required to achieve clearance below the 2001 DLCL at that time (40/250/400 μg/ft 2 for floors, window sills and troughs, respectively). It is possible that the percentage of samples achieving clearance may be even higher today, due to the 2021 revision of the DLCL to 10/100 μg/ft 2 , meaning clearance has had to be achieved at these lower levels or below, since that time

rvey respondents were only required to achieve clearance below the 2001 DLCL at that time (40/250/400 μg/ft 2 for floors, window sills and troughs, respectively). It is possible that the percentage of samples achieving clearance may be even higher today, due to the 2021 revision of the DLCL to 10/100 μg/ft 2 , meaning clearance has had to be achieved at these lower levels or below, since that time. Given lead-hazard control work has been subject to the current DLCL of 10/100 μg/ft 2 for some time, EPA is requesting comment from the regulated community regarding their ability to clear to 3/20/25 μg/ft 2 after various lead hazard control activities and given any additional cleaning necessary to make sure the dust-lead levels fall below the DLCL. See Unit IV.B.2.a. for more information on the LHCCS results for the alternative DLCL of 5/40/100 μg/ft 2 for floors, window sills and troughs, respectively.

b. Primary DLCL Modeling Results

EPA must understand the estimated health impacts of dust-lead exposure when selecting a DLCL that is reliable, effective, and safe, and in order to inform the EA. The TSD that accompanies this proposal includes evaluation of the 2021 DLCL (10/100 μg/ft 2 for floors and window sills), and the primary DLCL (3/20 μg/ft 2 for floors/window sills) and alternative DLCL (5/40 μg/ft 2 for floors/window sills) options. The unique dust-lead contribution to exposure from window troughs cannot be distinguished from window sills given the strong correlation between dust-lead loadings on the two surface types, the lack of data on access to window troughs versus window sills by children, and the paired impacts in window sills and window troughs from intervention studies addressing lead paint in window trim and casings. Further discussion on exposure to window troughs can be found in the TSD in Appendix C. As a result, exposure to window trough dust-lead and resultant benefits from a lowered DLCL for troughs is not calculated separately for this rulemaking

window sills by children, and the paired impacts in window sills and window troughs from intervention studies addressing lead paint in window trim and casings. Further discussion on exposure to window troughs can be found in the TSD in Appendix C. As a result, exposure to window trough dust-lead and resultant benefits from a lowered DLCL for troughs is not calculated separately for this rulemaking.

The TSD also describes modeling of dust-lead exposures at the specific DLCL options for window sills and floors only and estimates of both BLLs that were evaluated for children at each age up to age six, including age two (generally, this is the age of greatest modeled exposure), and lead-related reduction in IQ at age six was estimated from the lifetime average BLL (average of BLLs across the period prior to age six). More information on estimated potential impacts from dust-lead exposures analyzed in the TSD, can be found in Unit III. Technical Analyses and Unit IV.A.2.a. Modeled Approach.

Compared to the alternative DLCL option, the primary option (3/20/25 μg/ft 2 for floors, window sills and troughs) is expected to be more health protective in that it results in the least amount of dust-lead left on a surface after the completion of an abatement. The modeling results provided in the TSD show that young children in pre-1978 housing exposed to dust-lead loadings of 3 μg/ft 2 for floors and 20 μg/ft 2 for sills would have a 11.3% probability of exceeding a total BLL of 3.5 μg/dL (CDC's BLRV). This is lower than the 18.0% probability when exposed to the current DLCL of 10 μg/ft 2 for floors and 100 μg/ft 2 for window sills and the 13.9% probability when exposed to the alternative DLCL. Total BLL includes exposure from other media such as soil, diet, water, and air; even at zero dust- 2 ), is estimated to result in 1.6 to 16.0% probability of young children's BLL exceeding 1 to 2.5 μg/dL, compared to 3.2 to 23.0% probability for the alternative DLCL (5/40/100 μg/ft 2 )

ft 2 for floors and 100 μg/ft 2 for window sills and the 13.9% probability when exposed to the alternative DLCL. Total BLL includes exposure from other media such as soil, diet, water, and air; even at zero dust- 2 ), is estimated to result in 1.6 to 16.0% probability of young children's BLL exceeding 1 to 2.5 μg/dL, compared to 3.2 to 23.0% probability for the alternative DLCL (5/40/100 μg/ft 2 ). The primary DLCL is also estimated to have a 14.6% probability of exceeding 2 IQ points decrement from dust exposure, while the alternative DLCL is estimated to result in a 22.4% probability of exceeding 2 IQ points decrement from dust exposure. Ultimately, the primary DLCL option is expected to result in a higher reduction of dust-lead exposure than the alternative DLCL.

Table 5—Percent Exceedance Values for DLHS Candidates, Age: 2 Yr Old (30 Months) Approach Floor (μg/ft 2 ) Sill (μg/ft 2 ) Probability Total BLL >3.5 μg/dL (%) Total BLL >5 μg/dL (%) Dust only BLL >1 μg/dL (%) Dust only BLL >2.5 μg/dL (%) Zero 1 0 0 5.7 2.2 0.0 0.0 3/20 DLCL 3 20 11.3 4.5 16.0 1.6 5/40 DLCL 5 40 13.9 5.5 23.0 3.2 Current Standard 10 100 18.0 7.5 36.7 6.5 1 The exceedance values for zero dust-lead are provided for comparison with the DLHS candidates; it is not a candidate value. Table 6—Percent Exceedance Values for DLHS Candidates, Age: 6 Yr Old (72 Months) Approach Floor (μg/ft 2 ) Sill (μg/ft 2 ) Probability Total IQ >1pt (%) Total IQ >2pt (%) Dust only IQ >1pt (%) Dust only IQ >2pt (%) Zero 1 0 0 88.9% 48.7% 0.0% 0.0% 3/20 DLCL 3 20 98.2% 81.8% 51.4% 14.6% 5/40 DLCL 5 40 98.8% 85.1% 62.7% 22.4% Current Standard 10 100 99.4% 90.3% 75.8% 37.9% 1 The exceedance values for zero dust-lead are provided for comparison with the DLHS candidates; it is not a candidate value. c

t 2 ) Sill (μg/ft 2 ) Probability Total IQ >1pt (%) Total IQ >2pt (%) Dust only IQ >1pt (%) Dust only IQ >2pt (%) Zero 1 0 0 88.9% 48.7% 0.0% 0.0% 3/20 DLCL 3 20 98.2% 81.8% 51.4% 14.6% 5/40 DLCL 5 40 98.8% 85.1% 62.7% 22.4% Current Standard 10 100 99.4% 90.3% 75.8% 37.9% 1 The exceedance values for zero dust-lead are provided for comparison with the DLHS candidates; it is not a candidate value. c. Laboratory Capabilities for Primary DLCL

To better understand current laboratory capabilities for specific equipment types, and the impact that the primary and alternative DLCL options, especially given that a non-numeric DLHS would shift the LQSR “action level” to the DLCL, EPA spoke with nine NLLAP-recognized laboratories about their dust wipe testing programs (Refs. 56, 57, 58, 59, 60, 61, 62, 63 and 64). EPA was interested in information from laboratories who had high dust wipe testing capacity and laboratories that had both a flame atomic absorption spectroscopy (FAAS) and the more sensitive laboratory instruments such as inductively coupled plasma atomic emission spectroscopy (ICP-AES) or an inductively coupled plasma mass spectroscopy (ICP-MS). The Agency wanted additional background on ICP instruments and their use for dust wipe testing in general. Among the laboratories EPA spoke to, six were accredited to use FAAS, five were accredited to use ICP-AES, and two were accredited to use ICP-MS to analyze dust wipe samples for lead. Eight of the nine laboratories provide commercial testing services, four of which are the largest U.S. lead laboratories by dust wipe test volume.

ies provide commercial testing services, four of which are the largest U.S. lead laboratories by dust wipe test volume.

The information received from stakeholder outreach indicates that laboratories using ICP-AES equipment for dust wipe testing have a reporting limit of ≤3 μg/wipe. The five laboratories with ICP-AES capabilities have current reporting limits ranging from 0.5 μg/wipe to 3 μg/wipe. EPA believes that laboratories with more up-to-date instruments and optimized methods should be able to satisfy the LQSR dust wipe recommendations and the regulatory limit of the primary DLCL option of 3/20/25 μg/ft 2 and the quantitation limit of equal to or less than 50% of that level ( i.e., 1.5/10/12.5 μg/ft 2 ). If finalized as proposed, EPA believes that ICP-AES would likely become the instrument standard for dust wipe testing for lead at the NLLAP laboratories, as other technologies were not reported to consistently meet the quantitation limit described above. For more information on the on how the alternative DLCL compares or the impact it could have on NLLAP-recognized laboratories, see Unit IV.B.2.c.

FAAS has been the most popular choice for lead dust wipe testing because it has a lower purchase price and operating cost, is fast and easy to use, and was sensitive enough for the 2019 and 2021 rules' DLHS and DLCL of 10 μg/ft 2 on floors and 100 μg/ft 2 on window sills. As shown in the table below, Table 2-9 of the EA, over two-thirds of laboratories recognized under the NLLAP for lead dust wipe testing currently use FAAS, and over half of these NLLAP laboratories rely solely on FAAS (Ref. 14). EPA seeks information on whether and the extent to which labs that do not have any or have only limited ICP capabilities would adopt ICP technology for dust wipe testing if it were to effectively become the standard for dust wipe testing for lead. In addition, EPA requests comment on the timing, benefits, and challenges associated with ICP adoption

NLLAP laboratories rely solely on FAAS (Ref. 14). EPA seeks information on whether and the extent to which labs that do not have any or have only limited ICP capabilities would adopt ICP technology for dust wipe testing if it were to effectively become the standard for dust wipe testing for lead. In addition, EPA requests comment on the timing, benefits, and challenges associated with ICP adoption.

Table 7—Analytical Equipment Used for Lead Dust Wipe Testing by Laboratories Recognized Under NLLAP Program Equipment Total number of laboratories accredited Commercial laboratories accredited FAAS 56 54 ICP-AES 27 19 ICP-MS 5 1 FAAS and ICP-AES 10 10 FAAS and ICP-MS 2 2 ICP-AES and ICP-MS 1 1 Total 101 87 Sources: Methods described in accreditation certificates for NLLAP laboratories, and descriptions on laboratory websites. Several concerns about switching to ICP instruments were raised by laboratories, such as, a reduction in the throughput rate, need for additional equipment and staff due to the complexity of the machines (compared to FAAS), higher prices, delayed turnaround, and concerns over maintaining the current sample volume and ultimately whether to continue keeping dust wipe testing for lead in their portfolio/revisiting their business model. Based on the outreach conducted, laboratories indicated that the throughput rate on ICP-AES machines is roughly seven to 12 times slower than FAAS throughput. One major laboratory EPA spoke to estimated that they would have to purchase three to six new instruments, hire several highly qualified technicians, and run the laboratory on shifts over 24 hours to meet current demand for dust wipe tests conducted solely by ICP. This shift in instrumentation is estimated to increase both cost per sample as well as turnaround time. Laboratories mentioned that for clearance a substantial portion of their dust wipe testing clients request same-day or next-day turnaround on samples so that residents can quickly reoccupy their homes

ory on shifts over 24 hours to meet current demand for dust wipe tests conducted solely by ICP. This shift in instrumentation is estimated to increase both cost per sample as well as turnaround time. Laboratories mentioned that for clearance a substantial portion of their dust wipe testing clients request same-day or next-day turnaround on samples so that residents can quickly reoccupy their homes. Several laboratories doubted the technical feasibility of providing same-day or next-day turnarounds at sufficient volume should they switch to ICP technology thereby, potentially delaying homeowners from quickly reoccupying their homes and renters from quickly beginning occupancy or from quickly reoccupying their rental housing. Dust wipe testing by ICP-AES is also estimated to be about 125% more expensive per sample than testing by FAAS, and laboratories expressed concerned that less overall dust wipe testing will occur because state and local municipalities often have a fixed budget for their housing and health programs. See the EA for more specific information on the breakdown of the cost estimates of dust wipe testing. EPA also seeks information on the potential geographic impacts of the proposal on laboratory testing for lead dust wipes.

Finally, EPA found that several high-volume laboratories forecast that dust wipe test volumes will continue to grow over the next decade (Refs. 60 and 61). First, a growing proportion of laboratories' dust wipe testing business comes from landlords who need to comply with municipal housing regulations set by states or localities. Laboratories expect similar regulations to be enacted in the coming years, increasing demand for dust wipe testing for clearance (Ref. 61). Second, in recent years laboratories have received an increased volume of test samples generated by disaster recovery programs. When there is a natural disaster (such as a major flood) that requires clean-up and re-construction of pre-1978 housing, laboratories can receive an unexpected spike in dust wipe tests

d in the coming years, increasing demand for dust wipe testing for clearance (Ref. 61). Second, in recent years laboratories have received an increased volume of test samples generated by disaster recovery programs. When there is a natural disaster (such as a major flood) that requires clean-up and re-construction of pre-1978 housing, laboratories can receive an unexpected spike in dust wipe tests. Laboratories pointed out that the increasing rate of disaster-related demand spikes may overwhelm their capacity if only ICP can be used for dust wipe testing. If finalized as proposed, this rulemaking will also likely increase the amount of dust wipe testing required given the proposed regulatory levels. EPA seeks comment on the extent to which laboratories would be able to accommodate increased or emergency demand for dust wipe testing if this proposal is finalized.

The Agency is proposing 3/20/25 μg/ft 2 as the primary DLCL option due to the potential for risk reduction as discussed in Unit IV.B.1.b. Given information gathered via EPA's outreach to laboratories, EPA is concerned that setting clearance levels too low may deter participation in lead-hazard control programs and activities that require dust wipe testing or cause a market failure that does not allow the current volume of testing to continue. As a result, EPA is requesting comment on the reliability, effectiveness, and safety of the primary DLCL of 3/20/25 μg/ft 2 for floors, window sills, and troughs, including specifically the impact on laboratory capability as well as the accuracy of the information presented. See Unit VII. Request for Comments for more information.

2. Alternative DLCL

y the impact on laboratory capability as well as the accuracy of the information presented. See Unit VII. Request for Comments for more information.

2. Alternative DLCL

EPA is requesting comment on an alternative option to revise the DLCL for floors, window sills, and troughs from 10 μg/ft 2 , 100 μg/ft 2 and 400 μg/ft 2 , respectively to 5 μg/ft 2 , 40 μg/ft 2 , and 100 μg/ft 2 , respectively. EPA chose 5/40/100 μg/ft 2 as the alternate DLCL based on consideration of HUD's LHCCS, potential for risk reduction, an evaluation of laboratory capabilities as well as high confidence that these standards can be successfully implemented, as shown by the use of these clearance levels currently in NYC. Another consideration supporting the alternative DLCL option is to avoid potentially spreading the resources for LBP hazard mitigation so broadly that they may be diverted from scenarios that present the greatest risk. EPA notes that the EA indicates that the alternative DLCL option is estimated to have positive net benefits. See EA, Table ES-11.

a. Lead Hazard Control Clearance Survey

The LHCCS indicates that 73% of samples from 2010 to 2012 showed dust-lead levels at or below 5 μg/ft 2 for floors, 89% were at or below 40 μg/ft 2 for window sills, and 94% were at or below 100 μg/ft 2 for window troughs. As such, overall more than 72% of samples had dust-lead levels at or below the alternative DLCL option of 5/40/100 μg/ft 2 for floors, window sills and window troughs. This is compared to 64% of samples clearing at or below the primary DLCL option of 3/20/25 μg/ft 2 . As a result, EPA has high confidence that the alternative DLCL option is 2 after various lead hazard control activities and specialized cleaning.

b. Alternative DLCL Modeling Results

igh confidence that the alternative DLCL option is 2 after various lead hazard control activities and specialized cleaning.

b. Alternative DLCL Modeling Results

The alternative (5/40/100 μg/ft 2 for floors, window sills and troughs) represents a 50% or more reduction of dust-lead left on a surface following the completion of an abatement, when compared to the current DLCL (10/100/400 μg/ft 2 ). This alternative DLCL option would be beneficial to maintaining lower children's BLLs and protecting against associated h

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