# 88 FR 50444: Reconsideration of the Dust-Lead Hazard Standards and Dust-Lead Post-Abatement Clearance Levels

> Federal · Regulations · In force

URL: https://www.frixlaw.com/law-library/statutes/FR_PRORULE_2023-15073

## Section

- **Citation:** 88 FR 50444
- **Heading:** Reconsideration of the Dust-Lead Hazard Standards and Dust-Lead Post-Abatement Clearance Levels
- **Jurisdiction:** Federal
- **Kind:** Regulations
- **Status:** In force
- **Text as of:** August 14, 2026
- **Source:** Compiled text
- **Location:** Federal Register / Vol. 88 / 88 FR 50444

## Text

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:

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
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.
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)
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
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
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
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
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.
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
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).
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
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).
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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
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
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.
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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).
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)
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
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
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.
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
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).
1
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
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
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”)
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.
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
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.
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
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 e

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Source: Frix Law Library, https://www.frixlaw.com/law-library/statutes/FR_PRORULE_2023-15073. Check the current official text before relying on it. Not legal advice.