[Federal Register Volume 88, Number 146 (Tuesday, August 1, 2023)]
[Proposed Rules]
[Pages 50444-50483]
[FR Doc No: 2023-15073]

Vol. 88

Tuesday,

No. 146

August 1, 2023

Part III

Environmental Protection Agency

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40 CFR Part 745

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

Federal Register / Vol. 88, No. 146 / Tuesday, August 1, 2023 /
Proposed Rules

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 745

[EPA-HQ-OPPT-2023-0231; FRL-8524-01-OCSPP]
RIN 2070-AK91

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

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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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 ([micro]g/ft\2\) and 100 [micro]g/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 [micro]g/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 [micro]g/ft\2\, 100 [micro]g/ft\2\ and 400 [micro]g/
ft\2\ for floors, window sills, and window troughs to 3 [micro]g/ft\2\,
20 [micro]g/ft\2\, and 25 [micro]g/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:<PHONE_NUMBER>; email
address: [email protected]. 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: [email protected].

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. 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.
     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. 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: ``. . . 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
[mu]g/ft\2\ for floors and 100 [mu]g/ft\2\ for window sills (the 2019
DLHS Rule) (Ref. 2). In 2021, EPA promulgated a final rule to lower the
DLCL to 10 [mu]g/ft\2\ for floors and 100 [mu]g/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 [mu]g/ft\2\ for floors and 100
[mu]g/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). 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 [mu]g/ft\2\ to 3 [mu]g/ft\2\ for dust-lead for
floors, from 100 [mu]g/ft\2\ to 20 [mu]g/ft\2\ dust-lead for window
sills and from 400 [mu]g/ft\2\ to 25 [mu]g/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 [mu]g/ft\2\ dust-lead for
floors, 40 [mu]g/ft\2\ dust-lead for window sills, and 100 [mu]g/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

DLCL to be the same values, an opinion by the U.S. Court of Appeals for
the Ninth Circuit in May 2021 instructed EPA to consider only health
factors when setting the DLHS and affirmed that EPA could consider non-
health factors (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 [mu]g/ft\2\ for floors, 100
[mu]g/ft\2\ for window sills, and 400 [mu]g/ft\2\ for troughs, or the
previous DLCL of 40 [mu]g/ft\2\ for floors, 250 [mu]g/ft\2\ for window
sills, and 400 [mu]g/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.
    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. 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 [mu]g/ft\2\ and 250
[mu]g/ft\2\ to 10 [mu]g/ft\2\ and 100 [mu]g/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). 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

housing subject to HUD's Lead Safe Housing Rule (LSHR). As such, the
analysis estimates incremental costs and benefits for two categories of
events: (1) where dust-wipe testing occurs to comply with HUD's Lead-
Safe Housing Rule and (2) where dust wipe testing occurs in response to
blood lead testing that detects a blood lead level (BLL) above state or
Federal action levels. The following is a brief outline of the
estimated incremental impacts of this rulemaking.
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. 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. 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. 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. Additionally, the proposed DLCL of 3/20/25 [mu]g/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

obligated to offset. These compliance costs result from application of
EPA's standards in HUD's LSHR. While some HUD funding for LBP projects
exists, the Federal Government may not provide the funds necessary to
pay the entirety of the costs. These costs to public housing
authorities--estimated at $143 million for the primary option--cover
additional lead hazard reduction activities, cleaning, and dust-lead
testing to ensure that public housing units are in compliance with the
LSHR. EPA also estimates annual compliance costs of approximately $904
thousand to public school districts that operate a child-occupied
facility built before 1978. Additionally, states that have authorized
LBP Activities programs must demonstrate that they have DLHS and DLCL
at least as protective as the levels at 40 CFR 745.65 and 40 CFR
745.227. However, authorized states are under no obligation to continue
to administer the LBP Activities program, and if they do not wish to
adopt the new DLHS and DLCL they can relinquish their authorization. In
the absence of a state authorization, EPA will administer these
requirements. EPA provides a preliminary federalism summary impact
statement, which is found in Unit IX.E.
    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. 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). 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.
    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 [micro]g/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 [mu]g/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

U.S.C. 4822 and 4851 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. 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).

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. 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. 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)).
    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;

rather it simply provides property owners with recommendations as
appropriate (40 CFR 745.227(d)).
    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.
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.
    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). 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. 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 [mu]g/ft\2\ for
floors and 100 [mu]g/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). 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,

including feasibility and efficacy,'' when setting the DLHS, instead of
``set[ting] the hazard standards at the point at which the level [of]
dust-lead creates hazards to human health'' 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. 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. 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.
    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. 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. On top of these data gaps, EPA is
exploring the relationship between the two different units used in the
current definition (milligram per

square centimeter and percent by weight) to inform whether and how to
develop a conversion between the two. The search for relevant
information to develop the conversion and exploration of the
uncertainty involved with such a conversion is underway. EPA intends
the technical workshop to explore these issues and position the Agency
to reconsider the definition of LBP in light of the most current
scientific information. EPA will collaborate with HUD on the technical
workshop regarding these lead-based paint definition data needs.
    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). 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).
    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. 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. 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

approaches for developing the options for DLHS and DLCL.
    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 [micro]g/
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 [micro]g/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 [micro]g/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. 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. 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 [micro]g/ft\2\ and 100 [micro]g/
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 [micro]g/
ft\2\, 100 [micro]g/ft\2\ and 400 [micro]g/ft\2\ for floors, window
sills, and troughs to 3 [micro]g/ft\2\, 20 [micro]g/ft\2\, and 25
[micro]g/ft\2\, and requesting comment on an alternative DLCL option of
5 [micro]g/ft\2\, 40 [micro]g/ft\2\, and 100 [micro]g/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]

are truly hazardous'' and how to interpret the statutory criteria from
TSCA Section 401 (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
[micro]g/ft\2\ and 250 [micro]g/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 . . .
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 [micro]g/ft\2\ and 100 [micro]g/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. 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. 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. 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 [micro]g/ft\2\ and 100 [micro]g/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 [micro]g/ft\2\ for floors and 0.8 to 4.4
[micro]g/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

publicly available sources. GTZ values listed above are based on the
average of reporting limits at laboratories that currently report
numeric dust wipe loadings at levels 50% below the proposed DLCL
options. For the details of these calculations, see Sections 4.1 and
2.4.6 of the EA (Ref. 14). EPA also used a hypothetical dust-lead
loading value of zero. Details about how the TSD results are
interpreted are described in Unit IV.A.2., and the modeled results
themselves, which are supportive of the GTZ approach, are described in
Unit IV.A.3.
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.
    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 [micro]g/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 [mu]g/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).
    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 [micro]g/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
[micro]g/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
[micro]g/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 [micro]g/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 [mu]g/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 [micro]g/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 [micro]g/dL, based on young children's BLL in
the 2007-2010 NHANES, and in 2021 it was lowered to 3.5 [micro]g/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

of an MCL if ``it is not economically or technologically feasible to
ascertain the level of the contaminant.'' SDWA Section 1412(b)(7)(A).
In addition to the MCLG, EPA established treatment technique
requirements for lead taking into account several factors (56 FR
26460). Unlike many other drinking water contaminants, lead is
generally not present in source water but enters drinking water from
corrosion of plumbing materials that contain lead including lead
service lines and premise plumbing. Occurrence of lead in drinking
water is variable within a system and across systems due to factors
such as amount of lead in any individual site's plumbing, physical and
chemical characteristics of the water, and consumer use patterns.
Additionally, sources of lead can be beyond the control of the water
system to replace, such as premise plumbing. Water systems can adjust
or add treatment to control the corrosivity of the water to reduce lead
leaching from lead pipes and premise plumbing. EPA is required to
consider technical feasibility and costs when establishing the
treatment technique, which is analogous to EPA's development of the
clearance levels that also include non-health-based factors. Under
EPA's treatment technique rule for lead in drinking water, EPA
established a non-health-based action level which, if exceeded,
requires water systems to take actions to reduce elevated levels of
lead in drinking water.
    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''). 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. 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
[mu]g/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 [mu]g/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)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                Probability
                                                               Floor                     ---------------------------------------------------------------
                        Approach                            ([micro]g/    Sill ([micro]g/                                                  Dust only BLL
                                                             ft[sup2])       ft[sup2])    Total BLL >3.5   Total BLL >5    Dust only BLL  >2.5 [micro]g/
                                                                                [micro]g/dL     [micro]g/dL   >1 [micro]g/dL        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 [mu]g/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 [micro]g/
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 [mu]g/
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).

                                         Table 2--Percent Exceedance Values for Zero, Age: 6 Yr Old (72 Months)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                Probability
                                                           Floor ([mu]g/  Sill ([mu]g/ft ---------------------------------------------------------------
                        Approach                              ft \2\)          \2\)                                        Dust only IQ    Dust only IQ
                                                                                Total IQ >1pt   Total IQ >2pt       >1pt            >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).
    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 [mu]g/ft\2\
(i.e., 1 [mu]g/ft\2\ for floors and 10 [mu]g/ft\2\ for sills), 2/20
[mu]g/ft\2\, 3/30 [mu]g/ft\2\, and 5/40 [mu]g/ft\2\ and those values
were compared to the specified BLL and IQ metrics to estimate the
probability of exceeding the BLL or IQ targets. For example, a 2-year-
old living in pre-1978 housing exposed to 3 [mu]g/ft\2\ on floors and
30 [mu]g/ft\2\ on window sills would have a 4.8% probability of
exceeding, for example, 5 total [micro]g/dL BLL. Under this numeric
standard approach, EPA would plan to use the threshold of 5%
probability of exceedance for a child from the sub-population of
interest (i.e., young children living in pre-1978 housing and COFs).
This is similar to the 1 to 5% probability that was used in 2001 for
the lowest DLHS candidate (Ref. 6).
    Due to the aforementioned complexities with identifying a cutoff of
risk or specific IQ/BLL metrics of interest that would be acceptable
for purposes of setting the DLHS, as well as the reasons for favoring
GTZ, EPA is not proposing the numeric standard approach for the DLHS as
the Agency's preferred option. For specific discussion on the modeled
numeric DLHS candidates and IQ/BLL metrics, see Unit IV.A.3. EPA
welcomes comment on this numeric standard approach including the IQ/BLL
metrics under consideration (i.e., the target values of interest) and
the use of a 5% probability of exceedance.
b. Post-1977 Background Approach
    EPA also considered an approach to revise the DLHS that would align
target housing dust-lead levels with dust-lead levels in housing built
after lead-based paint was banned. This approach would result in
lowering the DLHS to the dust-lead background levels of housing built
after 1977 (known as ``post-1977 background''), which are presumably
not from LBP. In 1978, the CPSC banned lead in paint and similar
surface-coating materials for consumer use in excess of 0.06% and
revised the level in 2009 to 0.009% following the Consumer Product
Safety Improvement Act of

2008 (Pub. L. 110-314). As a result of CPSC's 1978 lead paint ban, the
focus of EPA's LBP activities program is target housing which includes
most pre-1978 housing and COFs.
    Post-1977 background dust-lead values were calculated from a
weighted geometric mean of the dust-lead loadings from the American
Healthy Homes Survey II and were found to be 0.2 [micro]g/ft\2\ for
floors and 0.8 [micro]g/ft\2\ for window sills (Refs. 14 and 52).
Setting the DLHS at the post-1977 background dust-lead levels would
allow EPA to focus on dust-lead hazards above what is expected in
housing without LBP (i.e., after CPSC established a maximum level of
lead in paint for consumer products, including home paints).
Establishing DLHS for target housing and COFs in this way, using post-
1977 background dust-lead levels, would address disparities in the
dust-lead levels that children in target housing may be exposed to and
the corresponding disparate health risks. This approach would also
align with the focus of Title X on lead hazards in housing constructed
before 1978. Using this approach, DLHS would be established at 0.2
[mu]g/ft\2\ for floors and 0.8 [mu]g/ft\2\ for window sills as the
dust-lead levels that would result in adverse human health effects.
However, there are questions about whether the post-1977 background
approach would as directly address the 2021 Court Opinion as the GTZ
approach. Due to those concerns and the reasons for favoring GTZ, EPA
is not proposing the post-1977 background approach for the DLHS as the
Agency's preferred option.
    As statistical points in a distribution of environmental data, the
calculation of the average background value is highly influenced by the
way in which data/measurements below the analytical detection limit are
treated. Further discussion on deriving these candidates can be found
in the TSD Section 2.3. The TSD models the health and exposure outcomes
based on these candidate DLHS of 0.2 [mu]g/ft\2\ for floors and 0.8
[mu]g/ft\2\ for window sills, as described in Unit IV.A.3. EPA welcomes
comment on this background approach, and its appropriateness given the
description above, 2021 Court Opinion and the statutory authority.
3. Modeled Results for All Three DLHS Approaches
    The TSD that accompanies this proposal evaluated the DLHS
candidates of all three approaches (i.e., GTZ, numeric standard, and
post-1977 background). Estimates for BLLs of children exposed to the
DLHS dust-lead loadings were evaluated for children at each age up to
age six, including age two (generally, age two is the age of greatest
modeled exposure), and lead-related reduction in IQ at age six was
estimated from the lifetime average BLL (average of BLLs across the
period prior to age six). This approach is consistent with the study
from which the BLL concentration-IQ response function was drawn. This
study related IQ quantified at about six years of age to each child's
lifetime average BLLs (based on blood Pb measurements taken from six
months up to age of the IQ test (Refs. 40 and 41). In the following
discussion, both the model results for two-year BLL and the estimates
of IQ change at six-years, are represented, referring to them as the
results for ``young children'' for brevity. EPA considered numerous
dust-lead loadings, including: 0.7/0.8 [mu]g/ft\2\, (i.e., 0.7 [mu]g/
ft\2\ for floors and 0.8 [mu]g/ft\2\ for window sills) which is the GTZ
option partnered with the primary DLCL option (3/20/25 [mu]g/ft\2\ for
floors, window sills, and window troughs respectively) and 2.2/4.4
[mu]g/ft\2\, which is the GTZ partnered with the alternative DLCL
option (5/40/100 [mu]g/ft\2\). Other modeled dust-lead loadings are
0.2/0.8 [mu]g/ft\2\, which is the post-1977 background dust-lead level,
1/10 [mu]g/ft\2\, 2/20 [mu]g/ft\2\, 3/30 [mu]g/ft\2\, 5/40 [mu]g/ft\2\,
and 10/100 [mu]g/ft\2\, which is the 2019 DLHS. Zero was also provided
for comparison purposes with the DLHS candidates and is not itself a
candidate value. More information on the TSD and the health/exposure
metrics (i.e., IQ and BLL decrements) that were analyzed can be found
in Unit III. and Unit IV.A.2.a.
    DLHS candidates associated with GTZ, post-1977 background, and the
numeric standard (1/10 [mu]g/ft\2\) approaches are associated with the
lowest BLLs when compared to the other numeric DLHS candidates (2/20
[mu]g/ft\2\, 3/30 [mu]g/ft\2\ and 5/40 [mu]g/ft\2\ and the current DLHS
of 10/100 [mu]g/ft\2\ for floors and window sills). The TSD modeling
results for young children exposed to dust-lead associated with the
loading candidates from the GTZ approach (which range from 0.7 to 2.2
[micro]g/ft\2\ for floors and 0.8 to 4.4 [micro]g/ft\2\ for window
sills depending on which DLCL it is coupled with, see Unit IV.A.1.a.
for more information) show that young children would have a 0.0 to
10.6% probability of exceeding an incremental BLL of 1 to 2.5 [mu]g/dL
(Tables 7-2 and 7-3 in the TSD). However, the results for GTZ partnered
with the primary DLCL option (0.7/0.8 [mu]g/ft\2\), and post-1977
background (0.2/0.8 [mu]g/ft\2\) are the only two DLHS candidates that
keep both the percentage of exceedance of incremental BLL of 1 to 2.5
[mu]g/dL below 5% probability (which is the threshold of interest EPA
identified).
    When comparing the three DLHS approaches to total BLL, the modeling
includes exposure from other media such as soil, diet, water, and air.
Importantly, even at zero dust-lead, children would still have a 5.7%
probability of exceeding the BLRV given the impact of these other
exposures. Thus, none of the considered DLHS candidates resulted in
less than 5% probability of exposed children's BLL exceeding the CDC
BLRV. However, the TSD modeling results did show that for young
children exposed to dust-lead loadings using the GTZ approach, the
post-1977 background approach or the numeric DLHS candidate of 1/10
[mu]g/ft\2\ would have approximately a 7.3 to 9.1% probability of
exceeding a total BLL of 3.5 [mu]g/dL, the CDC's BLRV. This is lower
than the 10.3 to 13.9% probability when exposed to other numeric DLHS
candidates (2/20 [mu]g/ft\2\, 3/30 [mu]g/ft\2\ and 5/40 [mu]g/ft\2\ for
floors and window sills) and the 18.0% probability when exposed to the
current DLHS of 10 [mu]g/ft\2\ for floors and 100 [mu]g/ft\2\ for
window sills. Therefore, while no DLHS option results in a less than
5.7% probability of exposed children's BLL exceeding the CDC BLRV given
their likely exposures to other sources of lead, the options with the
lowest levels (GTZ, post-1977 background, and 1/10 [mu]g/ft\2\) result
in exposed children experiencing about a two to three times less
likelihood of exceeding the CDC BLRV compared to the current DLHS.

                                    Table 3--Percent Exceedance Values for DLHS Candidates, Age: 2 Yr Old (30 Months)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                Probability
                                                                                ---------------------------------------------------------------
                        Approach                           Floor ([mu]g/   Sill ([mu]g/                                    Dust only BLL   Dust only BLL
                                                              ft\2\)          ft\2\)      Total BLL >3.5   Total BLL >5     >1 [mu]g/dL    >2.5 [mu]g/dL
                                                                                [mu]g/dL  (%)   [mu]g/dL  (%)        (%)             (%)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Zero \1\................................................               0               0             5.7             2.2             0.0             0.0

Post-1977 Background....................................             0.2             0.8             7.3             2.8             1.0             0.0
GTZ With 3/20 DLCL......................................             0.7             0.8             8.2             3.0             3.7             0.1
Numeric.................................................               1              10             9.1             3.3             6.6             0.5
GTZ With 5/40 DLCL......................................             2.2             4.4            10.1             3.9            10.6             1.0
Numeric.................................................               2              20            10.3             4.1            12.5             1.2
Numeric.................................................               3              30            11.8             4.8            17.2             2.0
Numeric.................................................               5              40            13.9             5.5            23.0             3.2
Current Standard........................................              10             100            18.0             7.5            36.7             6.5
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ The exceedance values for zero dust-lead are provided for comparison with the DLHS candidates; it is not a candidate value.

    DLHS candidates associated with GTZ and post-1977 background are
also estimated to be associated with the lowest IQ decrements when
compared to the other DLHS candidates (GTZ partnered with the
alternative DLCL, 1/10 [mu]g/ft\2\, 2/20 [mu]g/ft\2\, 3/30 [mu]g/ft\2\
and 5/40 [mu]g/ft\2\, and the current DLHS of 10/100 [mu]g/ft\2\ for
floors and window sills). GTZ partnered with the primary DLCL option
(0.7/0.8 [mu]g/ft\2\), and post-1977 background (0.2/0.8 [mu]g/ft\2\)
are the only two DLHS candidates estimated to have a 0.6 to 2.5%
probability of exceeding 2 points of incremental IQ loss from dust-
exposure, keeping the percentage of exceedance of 2 points of IQ loss
below 5% probability.

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

B. Dust-Lead Clearance Levels Approach

    TSCA Title IV granted EPA the authority to regulate LBP activities,
and to take into account reliability, effectiveness, and safety (15
U.S.C. 2682(a)(1)) when setting the DLCL. While considering those three
criteria, the 2001 LBP Hazards Rule modified the work practice
standards to include DLCL, which ``are used to evaluate the
effectiveness of cleaning following an abatement'' (Ref. 6). In both
the 2001 LBP Hazards Rule and the 2021 DLCL Rule, the DLCL were
finalized as the same value as the DLHS for floors and window sills.
When originally established, EPA considered the DLCL in the broader
context of Title X, and selected DLCL that were compatible with a
``workable framework for lead-based paint hazard evaluation and
reduction.'' EPA chose DLCL that were consistent with the DLHS in part
to ensure they were ``as easy as possible to understand and implement''
(Ref. 47). At that time EPA established the DLCL and the DLHS at 40
[mu]g/ft\2\ and 250 [mu]g/ft\2\ for floors and window sills, with a
separate DLCL of 400 [mu]g/ft\2\ for troughs.
    In 2021 the DLCL set by EPA continued to mirror the DLHS as it had
done historically, as the Agency explained that it wanted to update the
DLCL to achievable levels that would demonstrate elimination of dust-
lead hazards under the 2019 DLHS of 10 [mu]g/ft\2\ for floors and 100
[mu]g/ft\2\ for window sills. The 2021 updates to the DLCL restored
consistency between the DLCL and DLHS, which had been lowered in 2019
without a corresponding amendment to the DLCL. Previous public comments
received on the 2018 DLHS proposal and 2020 DLCL proposal favored
lowering the DLCL to be consistent with the DLHS (Refs. 53 and 54). As
a result, in 2021 EPA finalized DLCL of 10 [mu]g/ft\2\ for floors and
100 [mu]g/ft\2\ for window sills (the same levels as the DLHS), and
``EPA considered the achievability of these levels, how the lower dust-
lead loadings can be reliably detected by laboratories, the
effectiveness of these levels, and consistency with the revised 2019
standards and across the Federal Government'' (Ref. 3).
    The 2021 Court Opinion affirmed that ``TSCA [Title] IV gives the
EPA latitude to consider `reliability, effectiveness, and safety'''
when promulgating regulations ``[w]ith respect to implementation,
including abatement.'' A Cmty. Voice, 997 F.3d at 995 (Ref. 11). This
would include the DLCL as they represent part of post-abatement work
practices. The Court continued by emphasizing that this gives EPA more
discretion when setting the DLCL because they are relevant to the
implementation of remedial measures, rather than the identification of
a hazard (i.e., DLHS). The Court analogized this dichotomy to other
environmental statutory schemes (see also Unit IV.A.1.b. for EPA's
discussion of the

SDWA). The Court also held that the DLCL and DLHS are directly related
and must be reconsidered together. Yet the Court recognized the
difference in statutory authority and considerations (see Unit IV.A.
for more information on DLHS).
    In accordance with the 2021 Court Opinion, EPA is proposing to
revise the DLCL in the same proceeding as the reconsideration of the
2019 DLHS, and given the Court's direction for how to revise the DLHS
and DLCL, EPA is proposing clearance levels that are decoupled from the
DLHS (see Unit I.B and C. for more background on decoupling). EPA
evaluated the 2021 DLCL in accordance with the statute and is proposing
to revise the DLCL from 10 [mu]g/ft\2\, 100 [mu]g/ft\2\ and 400 [mu]g/
ft\2\ for floors, window sills, and troughs, respectively, to 3 [mu]g/
ft\2\, 20 [mu]g/ft\2\, and 25 [mu]g/ft\2\. EPA is proposing to revise
the DLCL in order to reduce exposure to dust-lead beyond the 2021
levels. Additionally, New York City (NYC) has lowered their clearance
levels since the 2021 DLCL final rule, which shows that levels below
EPA's 2021 DLCL are achievable. Discussion on NYC's clearance levels
can be found in Unit IV.B.2.d. Accordingly, EPA is also requesting
comment on an alternative DLCL of 5 [mu]g/ft\2\, 40 [mu]g/ft\2\, and
100 [mu]g/ft\2\, as well as whether another DLCL is appropriate given
reliability, effectiveness and safety and why, see Unit VII.
1. Selecting the Proposed DLCL
    EPA is proposing to revise the DLCL given the statutory criteria of
reliability, effectiveness, and safety, based on consideration of HUD's
Lead Hazard Control Clearance Survey (LHCCS), the potential for risk
reduction by lowering exposure to dust-lead, and an evaluation of
laboratory capabilities and capacity.
a. Lead Hazard Control Clearance Survey
    EPA collaborated with HUD to develop the 2015 LHCCS to examine
whether HUD's Office of Lead Hazard Control and Healthy Homes (OLHCHH)
Lead Hazard Control (LHC) grantees could achieve DLCL below the
standards at that time (40 [mu]g/ft\2\, 250 [mu]g/ft\2\ and 400 [mu]g/
ft\2\ for floors, window sills and troughs, respectively). LHC work
performed by the grantees must be conducted by LBP certified
individuals. Since most of the LHC grantees use commercial firms in
their area, HUD OLHCHH believes that the grantees are conducting a
large percentage of these activities and are therefore representative
of the regulated community.
    At that time, 98 LHC grantees completed the survey, giving HUD
information from housing units in which lead hazard control activities
took place from 2010 through 2012, for a total dataset of 1,552 housing
units including 7,211 floor samples and 4,893 window sill samples (Ref.
55). The data were analyzed to determine the percentage of samples
cleared at or below specific values. Numerical modeling was performed
to estimate loadings that fell below laboratory detection limits. For
more information on how that analysis was conducted please see Appendix
D of the EA (Ref. 14). Since the 2015 LHCCS report was published, to
the Agency's knowledge, there has not been any data or source of
information of this magnitude in terms of DLCL samples alongside the
details of the clearance process, including the number of tests
performed (with results) and the type of additional work or cleaning
performed. EPA found this 2015 LHCCS report still relevant and recent
enough to provide meaningful input to inform this reconsideration
rulemaking.
    In terms of the primary DLCL option EPA is proposing, 64% of the
2010 to 2012 samples showed dust-lead levels at or below 3 [mu]g/ft\2\
for floors, 64% were at or below 20 [mu]g/ft\2\ for window sills, and
64% were at or below 25 [mu]g/ft\2\ for window troughs. As a result,
approximately 64% of samples from the LHCCS data had dust-lead levels
at or below the primary DLCL option of 3 [mu]g/ft\2\ for floors, 20
[mu]g/ft\2\ for window sills and 25 [mu]g/ft\2\ for troughs, which EPA
believes is achievable, especially since the survey respondents were
only required to achieve clearance below the 2001 DLCL at that time
(40/250/400 [mu]g/ft\2\ for floors, window sills and troughs,
respectively). It is possible that the percentage of samples achieving
clearance may be even higher today, due to the 2021 revision of the
DLCL to 10/100 [mu]g/ft\2\, meaning clearance has had to be achieved at
these lower levels or below, since that time. Given lead-hazard control
work has been subject to the current DLCL of 10/100 [mu]g/ft\2\ for
some time, EPA is requesting comment from the regulated community
regarding their ability to clear to 3/20/25 [mu]g/ft\2\ after various
lead hazard control activities and given any additional cleaning
necessary to make sure the dust-lead levels fall below the DLCL. See