[Federal Register Volume 84, Number 145 (Monday, July 29, 2019)]
[Proposed Rules]
[Pages 36728-36760]
[FR Doc No: 2019-14022]

Vol. 84

Monday,

No. 145

July 29, 2019

Part III

Environmental Protection Agency

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40 CFR Part 751

Regulation of Persistent, Bioaccumulative, and Toxic Chemicals Under
TSCA Section 6(h); Proposed Rule

Federal Register / Vol. 84, No. 145 / Monday, July 29, 2019 /
Proposed Rules

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 751

[EPA-HQ-OPPT-2019-0080; FRL-9995-76]
RIN 2070-AK34

Regulation of Persistent, Bioaccumulative, and Toxic Chemicals
Under TSCA Section 6(h)

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: EPA is proposing a rule to address certain persistent,
bioaccumulative, and toxic chemicals identified pursuant to section
6(h) of the Toxic Substances Control Act (TSCA). These five chemicals
are: Decabromodiphenyl ether; phenol, isopropylated phosphate (3:1),
also known as tris(4-isopropylphenyl) phosphate; 2,4,6-tris(tert-
butyl)phenol; hexachlorobutadiene; and pentachlorothiophenol. This
proposed rule would restrict or prohibit manufacture (including
import), processing, and distribution in commerce for many uses of four
of these five chemical substances. EPA has evaluated the uses of
hexachlorobutadiene and is proposing no regulatory action. For the
other four, this proposal includes recordkeeping requirements.
Additional downstream notification requirements are proposed for
phenol, isopropylated phosphate (3:1).

DATES: Comments must be received on or before September 27, 2019. Under
the Paperwork Reduction Act, comments on the information collection
provisions are best assured of consideration if the Office of
Management and Budget (OMB) receives a copy of your comments on or
before August 28, 2019.

ADDRESSES: Submit your comments, identified by docket identification
(ID) number EPA-HQ-OPPT-2019-0080, by one of the following methods:
     Federal eRulemaking Portal: 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.
     Mail: Document Control Office (7407M), Office of Pollution
Prevention and Toxics (OPPT), Environmental Protection Agency, 1200
Pennsylvania Ave. NW, Washington, DC 20460-0001.
     Hand Delivery: To make special arrangements for hand
delivery or delivery of boxed information, please follow the
instructions at https://www.epa.gov/dockets/where-send-comments-epa-dockets.
    Additional instructions on commenting or visiting the docket, along
with more information about dockets generally, is available at https://www.epa.gov/dockets/commenting-epa-dockets.

FOR FURTHER INFORMATION CONTACT:
    For technical information contact: Cindy Wheeler, Chemical Control
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_ADDRESS>or Peter Gimlin, National Program Chemicals
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_ADDRESS>    For general information contact: The TSCA-Hotline, ABVI-Goodwill,
422 South Clinton Ave., Rochester, NY 14620; telephone number: (202)
554-1404; email address<EMAIL_ADDRESS>
SUPPLEMENTARY INFORMATION:

Table of Contents

    The information presented in this preamble is organized as follows:

I. Executive Summary
    A. Does this action apply to me?
    B. What is the Agency's authority for taking this action?
    C. What action is the Agency taking?
    D. Why is the Agency taking this action?
    E. What are the estimated incremental impacts of this action?
    F. What should I consider as I prepare my comments for EPA?
II. Background
    A. Why PBT Chemicals Are of Concern
    B. Overview of TSCA Sections 6(c) and 26 Considerations
    C. TSCA Section 6(h) and the 2014 Update to the TSCA Work Plan
for Chemical Assessments
    D. Overview of the Chemicals Subject to This Proposed Action
    E. Exposure and Use Assessment and Hazard Summary
III. Regulatory Assessment of the PBT Chemicals
    A. Regulatory Approach
    B. DecaBDE
    C. PIP (3:1)
    D. 2,4,6-TTBP
    E. HCBD
    F. PCTP
IV. Reasonably Ascertainable Economic Consequences of the Proposed
Rule
    A. Overview of Cost Methodology
    B. Estimated Costs of Proposed and Primary Alternative
Regulatory Actions
    C. Benefits
V. References
VI. Statutory and Executive Order Reviews
    A. Executive Order 12866: Regulatory Planning and Review and
Executive Order 13563: Improving Regulation and Regulatory Review
    B. Executive Order 13771: Reducing Regulations and Controlling
Regulatory Costs
    C. Paperwork Reduction Act (PRA)
    D. Regulatory Flexibility Act (FRA)
    E. Unfunded Mandates Reform Act (UMRA)
    F. Executive Order 13132: Federalism
    G. Executive Order 13175: Consultation and Coordination With
Indian Tribal Governments
    H. Executive Order 13045: Protection of Children From
Environmental Health Risks and Safety Risks
    I. Executive Order 13211: Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution or Use
    J. National Technology Transfer and Advancement Act (NTTAA)
    K. Executive Order 12898: Federal Actions To Address
Environmental Justice in Minority Populations and Low-Income
Populations

I. Executive Summary

A. Does this action apply to me?

    You may be potentially affected by this action if you manufacture
(including import), process, distribute in commerce, or commercially
use decabromodiphenyl ether (DecaBDE); phenol, isopropylated phosphate
(3:1) (PIP (3:1)), also known as tris(4-isopropylphenyl) phosphate;
2,4,6-tris(tert-butyl)phenol (2,4,6-TTBP); hexachlorobutadiene (HCBD);
or pentachlorothiophenol (PCTP) or products containing these chemicals,
especially electronics, plastic products, additives, hydraulic fluids,
or other industrial fluids. 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:
     Pipe, Duct and Boiler Insulation (NAICS Code 238290);
     Nonwoven Fabric Mills (NAICS Code 313230);
     Fabric Coating Mills (NAICS Code 313320);
     Petroleum Refineries (NAICS Code 324110);
     Petroleum Lubricating Oil and Grease Manufacturing (NAICS
Code 324191);
     Petrochemical Manufacturing (NAICS Code 325110);
     Other Basic Inorganic Chemical Manufacturing (NAICS Code
325180);
     All Other Basic Organic Chemical Manufacturing (NAICS Code
325199);

     Plastics Material and Resin Manufacturing (NAICS Code
325211);
     Paint and Coating Manufacturing (NAICS Code 325510);
     Adhesive Manufacturing (NAICS Code 325520);
     Polish and Other Sanitation Good Manufacturing (NAICS Code
325612);
     Custom Compounding of Purchased Resins (NAICS Code
325991);
     All Other Miscellaneous Chemical Product and Preparation
Manufacturing (NAICS Code 325998);
     Unlaminated Plastics Film and Sheet (except Packaging)
Manufacturing (NAICS Code 326113);
     Laminated Plastics Plate, Sheet (except Packaging), and
Shape Manufacturing (NAICS Code 326130);
     Urethane and Other Foam Product (except Polystyrene)
Manufacturing (NAICS Code 326150);
     All Other Plastics Product Manufacturing (NAICS Code
326199);
     All Other Rubber Product Manufacturing (NAICS Code
326299);
     Cement Manufacturing (NAICS Code 327310);
     Copper Rolling, Drawing, Extruding, and Alloying (NAICS
Code 331420);
     Machinery Manufacturing (NAICS Code 333);
     Computer and Peripheral Equipment Manufacturing (NAICS
Code 3341);
     Radio and Television Broadcasting and Wireless
Communications Equipment Manufacturing (NAICS Code 334220);
     Other Communications Equipment Manufacturing (NAICS Code
334290);
     Audio and Video Equipment Manufacturing (NAICS Code
334310);
     Other Communication and Energy Wire Manufacturing (NAICS
Code 335929);
     Motor Vehicle Manufacturing (NAICS Code 3361), e.g.,
automobile, aircraft, ship, and boat manufacturers and motor vehicle
parts manufacturers;
     Other Motor Vehicle Parts Manufacturing (NAICS Code
336390);
     Aircraft Manufacturing (NAICS Code 336411);
     Guided Missile and Space Vehicle Manufacturing (NAICS Code
336414);
     Household and Institutional Furniture Manufacturing (NAICS
Code 33712);
     Surgical Appliance and Supplies Manufacturing (NAICS Code
339113);
     Sporting and Athletic Goods Manufacturing (NAICS Code
339920);
     Doll, Toy, and Game Manufacturing (NAICS Code 33993);
     Automobile and Other Motor Vehicle Merchant Wholesalers
(NAICS Code 423110);
     Motor Vehicle Supplies and New Parts Merchant Wholesalers
(NAICS Code 423120);
     Furniture and Home Furnishing Merchant Wholesalers (NAICS
Code 4232);
     Insulation Materials (except Wood) Merchant Wholesalers
(NAICS Code 423330);
     Household Appliances, Electric Housewares, and Consumer
Electronics Merchant Wholesalers (NAICS Code 423620);
     Sporting and Recreational Goods and Supplies Merchant
Wholesalers (NAICS Code 423910);
     Toy and Hobby Goods and Supplies Merchant Wholesalers
(NAICS Code 423920);
     Other Chemical and Allied Products Merchant Wholesalers
(NAICS Code 424690);
     Farm Supplies Merchant Wholesalers (NAICS Code 424910);
     New Car Dealers (NAICS Code 441110);
     Boat Dealers (NAICS Code 441222);
     Automotive Parts and Accessories Stores (NAICS Code
441310);
     Furniture Stores (NAICS Code 442110);
     All Other Home Furnishing Stores (NAICS Code 442299) ;
     Gasoline Stations with Convenience Stores (NAICS Code
447110);
     Other Gasoline Stations (NAICS Code 447190);
     Children's and Infant's Clothing Stores (NAICS Code
448130);
     Sporting Goods Stores (NAICS Code 451110);
     Hobby, Toy, and Game Stores (NAICS Code 451120)
     General Merchandise Stores (NAICS Code 452);
     Aircraft Maintenance and Repair Services (NAICS Code
488190);
     All Other Consumer Goods Rental (NAICS Code 532289);
     Hazardous Waste Treatment and Disposal (NAICS Code
562211);
     Solid Waste Combustors and Incinerators (NAICS Code
562213);
     Marinas (NAICS Code 713930);
     General Automotive Repair (NAICS Code 811111).
    If you have any questions regarding the applicability of this
proposed action to a particular entity, consult the technical
information contact listed under FOR FURTHER INFORMATION CONTACT.

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

    Section 6(h) of TSCA, 15 U.S.C. 2601 et seq., directs EPA to issue
a proposed rule under TSCA section 6(a) on certain persistent,
bioaccumulative, and toxic (PBT) chemical substances. More
specifically, EPA must take action on those chemical substances
identified in the 2014 Update to the TSCA Work Plan for Chemical
Assessments (Ref. 1) that, with certain exceptions, EPA has a
reasonable basis to conclude are toxic and that with respect to
persistence and bioaccumulation score high for one and either high or
moderate for the other, pursuant to the TSCA Work Plan Chemicals:
Methods Document (Ref. 2) EPA published in 2012 (or a successor scoring
system), and exposure to which is likely under the conditions of use.
For the purposes of this proposed rule, these specific chemical
substances are hereinafter collectively referred to as the PBT
chemicals. TSCA section 6(a) regulatory requirements include: (1)
Prohibit or otherwise restrict the manufacturing, processing, or
distribution in commerce of such substances; (2) Prohibit or otherwise
restrict manufacturing, processing, or distribution in commerce of such
substances for particular uses or for uses in excess of a specified
concentration; (3) Require minimum warning labels and instructions; (4)
Require recordkeeping or testing; (5) Prohibit or regulate any manner
or method of commercial use; (6) Prohibit or otherwise regulate any
manner or method of disposal by a manufacturer, processor, or any other
person who uses or disposes of the chemical for commercial purposes;
and (7) Direct manufacturers and processors to give notice of the
determination to distributors and the public and replace or repurchase
substances. EPA must apply one or more of these requirements to the
extent necessary to meet the TSCA section 6(h)(4) statutory standard,
which is discussed in Unit II.C.

C. What action is the Agency taking?

    EPA is proposing to restrict or prohibit certain actions with
respect to four of the five PBT chemicals subject to this rulemaking.
As of the effective date of the final rule, affected persons would be
required to maintain, for three years from the date the record is
generated, ordinary business records that demonstrate compliance with
the restrictions, prohibitions, and other requirements.
    The extent of exposure, the severity of the hazard, and thus the
likely risk of these chemicals varies significantly. For example, the
evidence suggests that human exposure to hexachlorobutadiene is very
limited due in large part to the high waste treatment efficiencies
achieved by the chemical manufacturers. Additionally, the amount and
type of hazard information

varies substantially, from relatively well studied chemicals (e.g.
decabromodiphenyl ether) to data-sparse chemicals (e.g.,
pentachlorothiophenol).
    1. Decabromodiphenyl ether. DecaBDE (Chemical Abstracts Registry
Service Number (CASRN) 1163-19-5) is a flame retardant that has been
widely used in textiles, plastics, adhesives, and polyurethane foam.
For DecaBDE, this proposal would prohibit the manufacture (including
import), processing, and distribution in commerce of DecaBDE, and
articles and products to which DecaBDE has been added except for the
following:
     Manufacture, processing, and distribution in commerce for
use in parts for new aircraft and aerospace vehicles, and distribution
in commerce of the new vehicles containing such parts, for a period of
three years;
     Manufacture, processing, and distribution in commerce for
use in curtains in the hospitality industry, and the distribution of
the curtains themselves, for a period of 18 months;
     Manufacture, processing, and distribution in commerce for
use in replacement parts for the automotive and aerospace industries,
and distribution in commerce of the replacement parts themselves;
     Processing for recycling and distribution in commerce for
recycling of plastic that contained DecaBDE before the plastic was
recycled (i.e., the plastic to be recycled is from articles and
products that were originally made with DecaBDE), so long as no new
DecaBDE is added during the recycling process; and
     Processing and distribution in commerce of articles and
products made from recycled plastic that contained DecaBDE before the
plastic was recycled, so long as no new DecaBDE was added during the
recycling process or to the articles and products made from the
recycled plastic.
    2. Phenol, isopropylated phosphate (3:1). PIP (3:1) (CASRN 68937-
41-7) is a flame retardant, a plasticizer, and an anti-compressibility
and anti-wear additive. It is used in lubricants and hydraulic fluids
and in the manufacture of other compounds. For PIP (3:1), which is also
known as tris(4-isopropylphenyl) phosphate, this proposal would
prohibit processing and distribution in commerce of the chemical
substance, and products containing the chemical substance except for
the following:
     Processing and distribution in commerce for use in
aviation hydraulic fluid;
     Processing and distribution in commerce for use in
lubricants and greases; and
     Processing and distribution in commerce for use in new and
replacement parts for automobiles and other motor vehicles, and the
distribution in commerce of the parts to which PIP (3:1) has been
added.
    In addition, this rule would prohibit releases to water from the
non-prohibited processing, distribution in commerce, and commercial use
activities. Persons manufacturing, processing, and distributing PIP
(3:1), and products containing PIP (3:1), in commerce would be required
to notify their customers of these restrictions.
    3. 2,4,6-tris(tert-butyl)phenol. 2,4,6-TTBP (CASRN 732-26-3) is an
antioxidant that can be used as a fuel additive or lubricant additive,
as an intermediate in the manufacture of other compounds, and as a
waste fuel. For 2,4,6-TTBP, this proposal would prohibit the
distribution in commerce of 2,4,6-TTBP and products containing 2,4,6-
TTBP in any container with a volume of less than 55 gallons for any
use, in order to effectively prevent the use of 2,4,6-TTBP as a fuel
additive or fuel injector cleaner by consumers and small commercial
operations (e.g., automotive repair shops, marinas). It is EPA's intent
that the 55-gallon container restriction will ensure the continued fuel
additive or fuel injector cleaner use of this PBT only by commercial
operators who have the capacity to protect their workers who may come
into contact with 2,4,6-TTBP and whose workplaces are generally subject
to the standards promulgated by the Occupational Safety and Health
Administration (OSHA). This restriction also would prohibit processing
and distribution in commerce of 2,4,6-TTBP, and products containing
2,4,6-TTBP, for use as an oil or lubricant additive, regardless of
container size.
    4. Hexachlorobutadiene. HCBD (CASRN 87-68-3) is produced as a
byproduct in the production of chlorinated solvents and has also been
used in the past as an absorbent for gas impurity removal and as an
intermediate in the manufacture of rubber compounds. For HCBD, EPA has
evaluated the uses of hexachlorobutadiene and is proposing no
regulatory action for the reasons described in Unit III.E.
    5. Pentachlorothiophenol. PCTP (CASRN 133-49-3) is used in the
manufacture of rubber compounds. For PCTP, this proposal would prohibit
the manufacture (including import), processing, and distribution in
commerce of PCTP, and products containing PCTP, unless in
concentrations at or below 1% by weight.
    D. Why is the Agency taking this action?
    EPA is issuing this proposed rule to fulfill EPA's obligations
under TSCA section 6(h) to take timely regulatory action on PBT
chemicals--specifically, ``to address the risks of injury to health or
the environment that the Administrator determines are presented by the
chemical substance and [. . .] to reduce exposure to the substance to
the extent practicable.'' PBT chemicals remain in the environment for a
significant period of time and can accumulate in biota. Congress
directed EPA in TSCA section 6(h) to take expedited regulatory action
for certain PBT chemicals. As required by the statute, the Agency is
proposing risk management actions to reduce exposures to the PBT
chemicals to the extent practicable for the general population,
potentially exposed or susceptible subpopulations, and the environment.
Although EPA did not make an affirmative determination that risks are
presented by the five PBT chemicals due to the language of TSCA section
6(h), this proposal nevertheless meets the standards of TSCA section
6(h)(4).

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

    EPA has evaluated the potential costs of these proposed
restrictions and prohibitions and the associated reporting and
recordkeeping requirements. The ``Economic Analysis for Proposed
Regulation of Persistent, Bioaccumulative, and Toxic Chemicals under
TSCA section 6(h)'' (Economic Analysis) (Ref. 3), which is available in
the docket, is discussed in Unit IV, and is briefly summarized here.
Total quantified annualized social costs for the proposed rule under
the proposed option are approximately $43.5 million (at both 3% and 7%
discount rates). As discussed in more detail in Unit II.C., EPA did not
perform risk evaluations for these chemical substances, nor did EPA
develop quantitative risk estimates. Thus, EPA was not able to quantify
the benefits of reducing human and environmental exposures to these PBT
chemicals; therefore, the Economic Analysis (Ref. 3) qualitatively
discusses the benefits of reducing exposure under the proposed option
and the primary alternative regulatory action for the five PBT
chemicals.

F. What should I consider as I prepare my comments for EPA?

    See the commenting tips at https://www.epa.gov/dockets/commenting-epa-dockets when preparing and submitting your comments. Do not submit
CBI to EPA through regulations.gov or email. Clearly mark the part or
all of the information that you claim to be CBI. In addition to one
complete version of the comment that includes information claimed as
CBI, a copy of the comment that does not contain the information
claimed as CBI must be submitted for inclusion in the public docket.
Information so marked will not be disclosed except in accordance with
procedures set forth in 40 CFR part 2.
    EPA requests comment on all aspects of this proposal, including the
proposed regulatory actions for each of the PBT chemicals, the primary
alternative regulatory actions, and any other options that EPA has
considered or should consider. In particular, EPA is requesting comment
on its proposed determinations with respect to whether exposure is
likely and whether EPA's proposed regulatory actions achieve the
statutory directives to ``address the risks of injury to health and the
environment that the Administrator determines are presented by the
chemical substance and [. . .] reduce exposure to the substance to the
extent practicable.'' EPA also requests comment on all aspects of the
Economic Analysis (Ref. 3) accompanying this action. In taking final
action on this proposal, following review of comments, EPA may require
exposure reductions beyond those proposed here, or may reduce the scope
of the proposed exposure reductions.

II. Background

A. Why PBT Chemicals Are of Concern

    Toxic chemicals that persist and bioaccumulate are of concern
because they remain in the environment for long periods of time and
accumulate in the organisms exposed to them (i.e., can build up or
concentrate in body tissue). A chemical's persistence refers to the
length of time the chemical can exist in the environment before being
degraded at rates that prevent substantial buildup of the parent
chemical in the environment. Bioaccumulation is the net accumulation of
a chemical by an aquatic organism as a result of uptake from all
environmental sources. The term refers to both uptake of chemicals by
aquatic species from water (bioconcentration) and from ingested food
and sediment residues. PBT chemicals are toxic chemicals that are not
removed from the environment at rates adequate to prevent exposure to
aquatic or terrestrial organisms. Following exposure, PBT chemicals
increase in concentration in the exposed organism's tissues relative to
the concentrations in environmental media to which they are exposed.
Chemicals that persist and bioaccumulate have been found in humans,
other aquatic and terrestrial mammals, fish, shellfish, and birds.
    Biomagnification is the increase in concentration of a chemical in
the tissue of organisms along a series of predator-prey associations,
primarily through the mechanism of dietary accumulation and can be an
additional characteristic of PBT chemicals. Biomagnification in food
webs results in apex predators (e.g., eagles and orcas) being subject
to higher exposures of PBT chemicals via food. When humans consume
organisms from higher trophic levels (e.g., predator fish like tuna or
swordfish), humans often have increased tissue concentrations of PBT
chemicals due to biomagnification and therefore are exposed to
increased concentrations of the chemical.

B. Overview of TSCA Sections 6(c) and 26 Considerations

    1. TSCA section 6(c)(2) considerations. TSCA section 6(c)(2)
requires EPA to consider and publish a statement based on reasonably
available information with respect to the:
     Health effects of the chemical substance or mixture and
the magnitude of human exposure;
     Environmental effects of the chemical substance or mixture
and the magnitude of exposure of the environment;
     Benefits of the chemical substance or mixture for various
uses; and
     Reasonably ascertainable economic consequences of the
rule, including: The likely effect of the rule on the national economy,
small business, technological innovation, the environment, and public
health; the costs and benefits of the proposed and final rule and of
the one or more primary alternative regulatory actions that EPA
considered; and the cost effectiveness of the proposed rule and of the
one or more primary alternative regulatory actions that EPA considered.
    In addition, in selecting among prohibitions and other restrictions
available under TSCA section 6(a), EPA must factor in, to the extent
practicable, these considerations. Further, in deciding whether to
prohibit or restrict in a manner that substantially prevents a specific
condition of use of a chemical substance or mixture, and in setting an
appropriate transition period for such action, EPA must also consider,
to the extent practicable, whether technically and economically
feasible alternatives that benefit health or the environment would be
reasonably available as a substitute when the proposed prohibition or
other restriction takes effect.
    EPA's summary of the health and environmental effects of and the
potential for exposure to the five chemical substances subject to this
action can be found in Unit II.E., which discusses the Exposure and Use
Assessment (Ref. 4) and the Hazard Summary (Ref. 5).
    With respect to the costs and benefits of this proposal and the
alternatives EPA considered, as well as the impacts on small
businesses, the full analysis is presented in the economic analysis
document (Ref. 3). Due to the lack of risk information, EPA was not
able to quantify the benefits of this proposal and the alternatives. A
qualitative discussion of the potential benefits associated with the
proposed option for each chemical is provided in Unit IV.C. EPA
requests comment on all aspects of the benefits attributable to this
proposed action, including the impacts that the selection of
substitutes for those uses proposed to be restricted or prohibited may
have on the anticipated benefits.
    EPA considered the estimated costs to regulated entities as well as
the cost to administer and enforce the options. EPA took into account
reasonably available information about the functionality and
performance efficacy of the regulatory options and the ability to
implement the use of chemical substitutes or other alternatives. A
discussion of the costs EPA considered can be found in Units IV.A. and
IV.B., along with a discussion of the alternatives that EPA considered.
In addition, a discussion of the impacts on small businesses can be
found in Unit VI.D.
    With respect to the cost effectiveness of the proposed regulatory
action and the primary alternative regulatory action, EPA is unable to
perform a traditional cost-effectiveness analysis of the proposed
actions and alternatives for the PBT chemicals. The cost effectiveness
of a policy option would properly be calculated by dividing the
annualized costs of the option by a final outcome, such as cancer cases
avoided, or to intermediate outputs such as tons of emissions of a
pollutant curtailed. Without the supporting analyses for a risk
determination, EPA is unable to calculate either a health-based or
environment-based denominator. Thus, EPA is unable to perform a
quantitative cost-effectiveness analysis of the proposed and
alternative regulatory actions. However, by evaluating the

practicability of the proposed and alternative regulatory actions, EPA
believes that it has considered elements related to the cost
effectiveness of the actions, including the cost and the effect on
exposure to the PBT chemicals of the proposed and alternative
regulatory actions.
    With respect to the anticipated effects of this proposal on the
national economy, EPA considered the number of businesses and workers
that would be affected and the costs and benefits to those businesses
and workers (Ref. 3).
    The benefits of the five PBT chemicals subject to this proposal for
their various uses are discussed in Unit II.D. The technical
feasibility, economic feasibility, and reasonable availability of
alternatives that benefit health or the environment is discussed in
Unit III., in the Economic Analysis (Ref. 3), and in the document
entitled ``Persistence, Bioaccumulation, Environmental Hazard and Human
Health Hazard Ratings for Alternatives to PBT Chemicals Proposed for
Regulation'' (Ref. 5).
    The dates that the proposed restrictions would take effect are
discussed in Unit III.
    Finally, with respect to this proposal's effect on technological
innovation, EPA expects this action to spur innovation, not hinder it
(Ref. 3). In most cases, a wide variety of alternatives are available
for the uses that this proposal would prohibit or restrict.
    2. TSCA section 26 considerations. EPA has used scientific
information, technical procedures, measures, and methodologies that are
fit for purpose and consistent with the best available science. For
example, EPA based its proposed determination that human and
environmental exposures are likely to the five PBT chemicals subject to
this action on the Exposure and Use Assessment (Ref. 4) discussed in
Unit II.E.1, which underwent a peer review and public comment process,
as well as using best available science and methods sufficient to make
that determination. The extent to which the various information,
procedures, measures, and methodologies, as applicable, used in EPA's
decision-making have been subject to independent verification or peer
review is adequate to justify their use, collectively, in the record
for this rule. Additional information on the peer review and public
comment process, such as the peer review plan, the peer review report,
and the Agency's response to comments, can be found in the public
docket for this action (EPA-HQ-OPPT-2019-0080). In addition, in
accordance with TSCA section 26(i), EPA has made scientific decisions
based on the weight of the scientific evidence.

C. TSCA Section 6(h) and the 2014 Update to the TSCA Work Plan for
Chemical Assessments

    1. TSCA sections 6(h) and 6(a). TSCA section 6(h) requires EPA to
take expedited regulatory action under TSCA section 6(a) for certain
PBT chemicals identified in the 2014 Update to the TSCA Work Plan for
Chemical Assessments. More specifically, under TSCA section 6(h)(1)(A),
the subject chemical substances are those that:
     EPA has a reasonable basis to conclude are toxic and that
with respect to persistence and bioaccumulation score high for one and
either high or moderate for the other, pursuant to the 2012 TSCA Work
Plan Chemicals: Methods Document or a successor scoring system;
     Are not a metal or a metal compound; and
     Are chemical substances for which EPA has not completed a
TSCA Work Plan Problem Formulation, initiated a review under TSCA
section 5, or entered into a consent agreement under TSCA section 4,
prior to June 22, 2016, the date that the Frank R. Lautenberg Chemical
Safety for the 21st Century Act became law.
    In addition, in order for a chemical substance to be subject to
expedited action, TSCA section 6(h)(1)(B) states that EPA must find
that exposure to the chemical substance under the conditions of use is
likely to the general population or to a potentially exposed or
susceptible subpopulation identified by the Administrator (such as
infants, children, pregnant women, workers or the elderly), or to the
environment on the basis of an exposure and use assessment conducted by
EPA. EPA also considers consumers to be a potentially exposed or
susceptible subpopulation for the purposes of this rule in addition to
the groups identified in the statutory definition at TSCA section
3(12), such as workers.
    For chemical substances subject to TSCA section 6(h), EPA must
issue a proposed rule by June 22, 2019, and a final rule no later than
18 months after the proposal is issued. The statute further provides
that the Administrator shall not be required to conduct risk
evaluations on chemical substances that are subject to TSCA section
6(h)(1).
    TSCA section 6(a) prohibitions and other restrictions can include
one or more, or a combination of, the following actions:
     A requirement either prohibiting or otherwise restricting
the manufacturing, processing, or distribution in commerce of such
substance or mixture, or limiting the amount of such substance or
mixture which may be manufactured, processed, or distributed in
commerce (TSCA section 6(a)(1)).
     A requirement either prohibiting or otherwise restricting
the manufacture, processing, or distribution in commerce of such
substance or mixture for (i) a particular use or (ii) a particular use
in a concentration in excess of a level specified by the Administrator
in the rule imposing the requirement, or limiting the amount of such
substance or mixture which may be manufactured, processed, or
distributed in commerce for (i) a particular use or (ii) a particular
use in a concentration in excess of a level specified by the
Administrator in the rule imposing the requirement (TSCA section
6(a)(2)).
     A requirement that such substance or mixture or any
article containing such substance or mixture be marked with or
accompanied by clear and adequate minimum warnings and instructions
with respect to its use, distribution in commerce, or disposal or with
respect to any combination of such activities (TSCA section 6(a)(3)).
     A requirement that manufacturers and processors of such
substance or mixture make and retain records of the processes used to
manufacture or process such substance or mixture or monitor or conduct
tests which are reasonable and necessary to assure compliance with the
requirements of any rule applicable under this subsection (TSCA section
6(a)(4)).
     A requirement prohibiting or otherwise regulating any
manner or method of commercial use of such substance or mixture (TSCA
section 6(a)(5)).
     A requirement prohibiting or otherwise regulating any
manner or method of disposal of such substance or mixture, or of any
article containing such substance or mixture, by its manufacturer or
processor or by any other person who uses, or disposes of, it for
commercial purposes (TSCA section 6(a)(6)).
     A requirement directing manufacturers or processors of
such substance or mixture to give notice of such determination to
distributors in commerce of such substance or mixture and, to the
extent reasonably ascertainable, to other persons in possession of such
substance or mixture or exposed to such substance or mixture, to give
public notice of such determination, and to replace or repurchase such
substance or mixture as elected by the person to which the requirement
is directed. Prohibit or otherwise restrict the manufacturing,

processing, or distribution in commerce of such substances (TSCA
section 6(a)(7)).
    TSCA section 6(h)(4) directs EPA, in selecting among the
prohibitions and restrictions in section 6(a), to ``address the risks
of injury to health or the environment that the Administrator
determines are presented by the chemical substance and [. . .] reduce
exposure to the substance to the extent practicable.'' EPA interprets
the directive in TSCA section 6(h) regarding issuance of a TSCA section
6(a) rule to require EPA to issue a rule to satisfy TSCA section 6(h)
requirements, using the regulatory prohibitions and other restrictions
identified in TSCA section 6(a)(1)-(7), applying other provisions of
TSCA section 6 applicable to TSCA section 6(a) rules consistent with
the direction in TSCA section 6(h), but not applying those provisions
of TSCA section 6(c) that conflict with TSCA section 6(h), in the sense
that those provisions assume the existence of a TSCA section 6(b) risk
evaluation, whereas TSCA section 6(h)(2) specifically provides that EPA
is not required to conduct a risk evaluation. EPA invites public
comment on this interpretation and seeks input on other possible
interpretations.
    2. Address risks and reduce exposure to the extent practicable.
TSCA section 6(h)(1) through (4) requires EPA to issue a TSCA section
6(a) rule to ``address the risks of injury to health or the environment
that the Administrator determines are presented by the chemical
substance and [. . .] reduce exposure to the substance to the extent
practicable.''
    EPA began by compiling use information on each of the five PBT
chemicals that EPA preliminarily determined met the criteria for
expedited action. Separate use documents were developed for each of the
five PBT chemicals and made available for public comment in August of
2017 (Refs. 6, 7, 8, 9, and 10).
    EPA then conducted a review of available literature with respect to
the PBT chemicals discussed in this proposal to identify, screen,
extract, and evaluate exposure information reasonably available for
each. The information gathered is presented in the document entitled
``Exposure and Use Assessment of Five Persistent, Bioaccumulative and
Toxic Chemicals'' (Exposure and Use Assessment) (Ref. 4). The exposure
information presented in the Exposure and Use Assessment document was
not intended to comprehensively discuss all possible nor use-specific
exposure scenarios presented by the PBT chemicals evaluated, but rather
to describe a broad range of potential exposures that would enable EPA
to determine whether exposure to these PBT chemicals is likely for the
purposes of TSCA section 6(h)(1)(B). The Exposure and Use Assessment
was peer reviewed; the peer review comments and the Agency's responses
can be found in the public docket at EPA-HQ-OPPT-2018-0314.
    In addition, EPA compiled hazard information on the five PBT
chemicals discussed in this proposal. The information is presented in
the document entitled ``Environmental and Human Health Hazards of Five
Persistent, Bioaccumulative, and Toxic Chemicals'' (Hazard Summary)
(Ref. 5). To create this document, which presents a limited summary of
the hazards of these chemical substances, environmental and human
health hazard data were compiled from various primary and secondary
sources of reasonably available information. The information in the
Hazard Summary does not represent an exhaustive literature review nor
is it an analysis of relative importance or comparative dose-response
among hazards. The hazard data are reported from the literature with no
additional analysis or assessment.
    The information compiled by EPA in the Exposure and Use Assessment
is useful in characterizing the exposures by these PBT chemicals. EPA
identified and included available information about potentially exposed
and susceptible subpopulations during the development of both the
Exposure and Use Assessment (Ref. 4) and the Hazard Summary (Ref. 5).
    The statute provides that EPA shall: (1) ``Address the risks of
injury to health or the environment that the Administrator determines
are presented by the chemical substance'' and (2) ``reduce exposure to
the substance to the extent practicable.'' (TSCA section 6(h)(4)). With
respect to the first requirement, EPA reviewed the hazard and exposure
information on the five PBT chemicals as described previously. While
this information identified hazards and exposures for the PBT
chemicals, the information for these five chemicals did not provide a
basis for EPA to develop scientifically robust and representative risk
estimates to evaluate whether or not any of the chemicals present a
risk of injury to health or the environment. EPA does not interpret
TSCA section 6(h)(4), specifically the language directing EPA to
``address the risks of injury to health or the environment that the
Administrator determines are presented,'' to require EPA to determine,
through a risk assessment or risk evaluation, whether risks are
presented. EPA believes this reading gives EPA the flexibility Congress
intended for issuance of an expedited rule for PBTs without compelling
a risk evaluation to support this rulemaking. EPA did not perform a
systematic review or a weight of the scientific evidence assessment for
the hazard characterization of these chemicals. As a result, the
characterization is not definitive or comprehensive. Other information
on these chemicals may exist in addition to the studies summarized in
the Hazard Summary that could refine the characterization. EPA does not
believe that a systematic review would change our proposed risk
management determinations as TSCA section 6(h)(4) requires EPA to
reduce exposure to the substance to the extent practicable, regardless
of risk. EPA is seeking public comment on the decision not to pursue a
systematic review for these five chemicals and the impact of this
decision on the PBT rulemaking.
    As required by the statute, the Agency is proposing risk management
actions to reduce exposures to the PBT chemicals to the extent
practicable. Although EPA did not make an affirmative determination
that risks are presented by the five PBT chemicals due to the language
of TSCA section 6(h), this proposal nevertheless meets the standards of
TSCA section 6(h)(4).
    With respect to the second requirement, the term ``practicable'' is
not defined in TSCA. EPA interprets this requirement as generally
directing the Agency to consider such factors as achievability,
feasibility, workability, and reasonableness. In addition, EPA's
approach to determining whether particular prohibitions or restrictions
are practicable is informed in part by a consideration of certain other
provisions in TSCA section 6. For example, TSCA section 6(c)(2)(A)
provides a list of factors that EPA must consider in promulgating a
rule under TSCA section 6(a), and EPA's statement on those factors can
be found in Unit II.B. Those factors include the costs and benefits of
the rule, along with the effects on health and the environment, the
magnitude of human and environmental exposure, the benefits of the
chemical substance for various uses, and other factors, such as the
effect of the rule on the national economy, small business, and
technological innovation. In addition, pursuant to TSCA section
6(c)(2)(B), in selecting the appropriate TSCA section 6(a) regulatory
approach to take, EPA is directed to ``factor in, to the extent
practicable'' those same considerations. EPA invites public comment on
the

factors that should be considered in determining whether a particular
prohibition or restriction is practicable.
    3. The TSCA Work Plan for Chemical Assessments. The 2012 TSCA Work
Plan Chemicals identified a list of chemicals for assessment by EPA
(Ref. 11). The screening process for identifying these chemicals is
described in the TSCA Work Plan Chemicals: Methods Document (Ref. 2).
Chemicals were evaluated and received a score through the application
of a numerical algorithm. This score was based on three
characteristics: hazard, exposure, and potential for persistence/
bioaccumulation. Using this system, chemicals were sorted into one of
four bins. Chemicals able to be scored on all three characteristics
were scored as High (3), Moderate (2), or Low (1) based on their
available information. The data used to determine the hazard score for
each chemical were obtained through specified data sources (Ref. 2,
Appendix A). The hazard data reviews on each chemical were not
exhaustive and did not rise to the level of assessments. Chemicals were
scored on the basis of readily available data, and no judgment was made
concerning gaps in or completeness of the available data set for a
given chemical. The hazard score was determined based on three hazard
levels, and each hazard level had a corresponding hazard rank (High-3,
Moderate-2, and Low-1). The concentration ranges or characteristics
corresponding to each hazard level are identified in the TSCA Work Plan
Chemicals: Methods Document (Ref. 2, pp. 8-9). The highest hazard rank
score a chemical received for any single human health or environmental
toxicity endpoint became its hazard score (Ref. 2).
    Persistence scoring consisted of the evaluation of the potential
half-life in air, water, soil, and sediment while considering the
expected partitioning characteristics of the chemicals and all
potential removal pathways based on standard physical-chemical
properties and environmental fate parameters. Specified data sources
(Ref. 2, Appendix B) were searched to locate studies on biotic and
abiotic transformation (e.g., biodegradation, hydrolysis, photolysis)
to estimate half-lives for the chemicals in the environment.
Bioaccumulation scoring consisted of evaluation of bioaccumulation/
bioconcentration (measured or estimated BAF/BCF) data. When BAF data
were not available, bioconcentration data (measured or estimated) were
used to evaluate the potential for a chemical to bioaccumulate in
organisms in the environment. In the absence of test data establishing
the chemical's measured persistence or bioaccumulation potential, EPA
used its EPI SuiteTM model to derive a ranking for the
chemical (Ref. 2).
    Scores were assigned independently for persistence potential and
bioaccumulation potential; the independent scores were added together
to derive a single score for persistence/bioaccumulation. Chemicals
with a combined score of 5-6 were scored as High (3) for persistence/
bioaccumulation, a combined persistence and bioaccumulation score of 3-
4 was scored as Moderate (2), and a combined score of 1-2 was scored as
Low (1). Chemicals with High or Moderate hazard or persistence/
bioaccumulation scores that could not be scored for exposure because of
an absence of data, together with chemicals that could not be scored
for hazard, were identified separately as potential candidates for
information gathering. In 2014, EPA applied the screening process for
exposure information described in the TSCA Work Plan Chemicals: Methods
Document (Ref. 2) to update its list of chemicals on the TSCA Work Plan
for Chemical Assessments. This update focused primarily on updating the
exposure score to reflect updated industry data submitted to EPA
through the Toxics Release Inventory (TRI) (40 CFR part 372) in 2011
and the TSCA Chemical Data Reporting (CDR) rule (40 CFR part 711) in
2012 on chemical releases and potential exposures, respectively. The
2014 Update to the TSCA Work Plan for Chemical Assessments included a
list of 90 chemicals and chemical categories; the TSCA amendments
passed in 2016 as part of the Frank R. Lautenberg Chemical Safety for
the 21st Century Act reference the 2014 Update to the TSCA Work Plan
for Chemical Assessments in several places, including TSCA section
6(h).
    In accordance with TSCA section 6(h)(1), chemical substances that
meet the criteria described therein are subject to expedited rulemaking
without the risk evaluations required for other TSCA Work Plan
chemicals prior to initiating TSCA section 6(a) risk management
actions. EPA interprets the TSCA section 6(h)(1)(A) provision
pertaining to chemical substances ``that the Administrator has a
reasonable basis to conclude are toxic,'' as referring to the toxicity
score identified in the 2014 Update to the TSCA Work Plan for Chemical
Assessments, and likewise focused on toxicity scores of high or
moderate. In addition, EPA conducted the screening level literature
search described in the peer-reviewed Hazard Summary to provide
additional information and support for the hazard score assigned to
these five chemicals in the 2014 Update to the TSCA Work Plan for
Chemical Assessments. The information EPA has collected and reviewed in
developing this proposal provides no basis to call into question the
scoring for persistence, bioaccumulation, and toxicity performed in
2014 for these five PBT chemicals pursuant to the screening process
described in the TSCA Work Plan Chemicals: Methods Document.
    EPA is proposing to determine that five chemical substances meet
the TSCA section 6(h)(1)(A) criteria for expedited action. These
substances are: DecaBDE; PIP (3:1); 2,4,6-TTBP; HCBD; and PCTP.
    A manufacturer of two other chemical substances on the 2014 Update
to the TSCA Work Plan for Chemical Assessments submitted a timely
request to EPA for risk evaluations pursuant to TSCA section 6(h)(5).
As a result of the request, these two chemicals: Ethanone, 1-
(1,2,3,4,5,6,7,8-octahydro-2,3,5,5-tetramethyl-2-naphthalenyl) and
Ethanone, 1-(1,2,3,4,5,6,7,8-octahydro-2,3,8,8-tetramethyl-2-
naphthalenyl) are excluded from this proposed rule (Ref. 12).
D. Overview of the Chemicals Subject to This Proposed Action
    The use information presented in this Unit is based on the EPA's
review of the available information, as presented in the use documents
developed for each of the PBT chemicals (Refs. 6, 7, 8, 9, and 10), as
well as public comments on the use documents and other stakeholder
input.
    1. Decabromodiphenyl ether (DecaBDE). (i) Use background: DecaBDE
is used as an additive flame retardant in plastic enclosures for
televisions, computers, audio and video equipment, textiles and
upholstered articles, wire and cables for communications and
electronics, and other applications (Ref. 6). DecaBDE is also used as a
flame retardant for multiple applications in the aerospace and
automotive industries, including replacement parts for aircraft and
cars (Refs. 13 and 14). Examples of products that have been made with
DecaBDE as a flame retardant include:
     Consumer products made of both hard and soft plastics,
such as furniture and furnishings, foam in furniture or mattresses,
computer casings, and other plastic products including toys and other
children's products (such as play structures);
     Fabrics and textiles, such as apparel, furniture and
furnishings,

curtains, and construction and building materials;
     Rubber articles, such as wire casings and other rubber
articles; and
     Complex articles in road vehicles and other vehicles for
passengers and goods, such as cars, trucks, and airplanes; and
machinery and mechanical appliances.
    DecaBDE can also be found in plastic materials recycled from
plastic products originally made with DecaBDE.
    EPA presented its initial research into DecaBDE uses in the August
2017 ``Preliminary Information on Manufacturing, Processing,
Distribution, Use, and Disposal'' document on DecaBDE (Ref. 6). EPA
received comments from 12 entities on the Preliminary Information
document. EPA also communicated with dozens of companies, industry
groups, chemical users, academic experts, states, and other
stakeholders to identify and verify uses of DecaBDE (Ref. 6). These
interactions and comments further informed EPA's understanding of the
current status of uses for DecaBDE. Public comments and stakeholder
meeting summaries are available in the public docket at EPA-HQ-OPPT-
2016-0724.
    In 2009, based on the EPA-Industry DecaBDE Phase-Out Initiative,
domestic manufacturers and importers of commercially available DecaBDE
agreed to voluntarily phase out the manufacture and import of the
chemical no later than December 31, 2013 (Ref. 15). For the 2012 and
2016 CDR periods, data reported to EPA indicate that five sites
manufactured (including imported) DecaBDE in the United States between
2011 and 2015 (Refs. 16 and 17). The total volume of DecaBDE
manufactured (including imported) in the United States in 2011 was
18,110,827 lbs (Ref. 16). For the 2016 reporting period, the total
volume of DecaBDE manufactured (including imported) in the United
States was 16,696,951 lbs in 2012, between 1,000,000 and 10,000,000 lbs
in 2013, between 100,000 and 500,000 lbs in 2014, and between 500,000
and 1,000,000 lbs in 2015. Actual production volume for years 2013
through 2015 is claimed in CDR as confidential business information
(Ref. 17). Data reported to EPA from TRI show a general decline of
DecaBDE releases, with 259,102 lbs of total on- and off-site reported
releases of DecaBDE from 24 sites in 2016, and 67,248 lbs of total on-
and off-site reported releases of DecaBDE from 17 sites in 2017. Of
these 17 sites, one site reported import of the chemical, 14 reported
processing of DecaBDE, and at the other two sites the specific
activities are unknown (Refs. 18 and 19). EPA requests comment as to
why some companies are still processing and using DecaBDE despite
phase-out initiatives and the availability of relatively inexpensive
substitutes.
    (ii) What are the beneficial properties of DecaBDE for various
uses? DecaBDE is a brominated flame retardant that has been added to
plastics, textiles, and other materials. When fire occurs, DecaBDE and
other polybrominated diphenyl ethers (PBDEs), are part of vapor-phase
chemical reactions that interfere with the combustion process, thus
delaying ignition and inhibiting the spread of fire. DecaBDE has been
considered an economical flame retardant because relatively small
quantities are necessary to be effective (Ref. 6).
    (iii) What are the 2014 Update to the TSCA Work Plan for Chemical
Assessments scores for DecaBDE? DecaBDE scored high (3) for hazard
(based on developmental effects in mammals and aquatic toxicity); high
(3) for exposure (based on its use in textiles, plastics, and
polyurethane foam; and information reported to CDR and TRI); and high
(3) for persistence and bioaccumulation (based on high environmental
persistence and high bioaccumulation potential). The overall screening
score for DecaBDE was high (9).
    (iv) Regulatory actions pertaining to DecaBDE. DecaBDE is regulated
as a PBT chemical by federal, state, and international agencies. They
are briefly summarized in this unit. More detailed information can be
found in the Economic Analysis (Ref. 3). In addition, the OSHA
regulations discussed in Unit III.A apply to commercial and industrial
workplaces.
    At the Federal level, under TSCA, DecaBDE was one of the chemical
substances required to be tested for dioxin/furan contamination as
outlined in 40 CFR part 766. DecaBDE manufacturing, processing, and use
information is reportable under CDR (40 CFR part 711). Under the CDR
rule, EPA collects basic exposure-related information on the types,
quantities and uses of chemical substances produced domestically and
imported into the U.S. Under TSCA section 8(e), manufacturers
(including importers), processors, and distributors must immediately
notify EPA if they obtain information that supports the conclusion that
a chemical substance or mixture presents a substantial risk of injury
to health or the environment. Four such notifications were received for
DecaBDE between 1996 and 2002. Under the Emergency Planning and
Community Right-to-Know Act (EPCRA), DecaBDE has been on the TRI list
of reportable chemicals since 1988 (Ref. 20). TRI tracks the management
of certain toxic chemicals that may pose a threat to human health and
the environment. U.S. facilities in different industry sectors must
report annually how much of each chemical is released to the
environment or managed through recycling, energy recovery and
treatment. A release of a chemical for TRI purposes means that it is
emitted to the air or water, or placed in some type of land disposal.
    Several states have taken action on DecaBDE. In California, DecaBDE
is listed as a candidate chemical by the Department of Toxic Substances
Control and as a priority chemical through the California Environmental
Contaminant Biomonitoring Program. Starting in 2020, California will
also prohibit the use of flame retardants (including DecaBDE) above
1000 parts per million (ppm) in children's products, mattresses, and
upholstered furniture. Hawaii prohibits the manufacture, use, sale, and
distribution of televisions, computers, upholstered furniture,
mattresses, and mattress pads containing DecaBDE greater than 0.1% by
weight. In Maine, DecaBDE is listed as a chemical of high concern; it
is banned in the use of new shipping pallets (though recycled pallets
are exempted), and manufacturers or distributors who use DecaBDE in
certain children's products are required to report to the Department of
Environmental Protection. In Maryland, the sale of products that
contain more than 0.1% DecaBDE by mass is prohibited, though the
recycling of articles containing DecaBDE is exempted. New Jersey and
Pennsylvania include DecaBDE on their hazardous substances lists under
right-to-know legislation. DecaBDE is one of Oregon's 66 high priority
chemicals of concern for children's health. Vermont prohibits DecaBDE
in certain home products and manufacturers using DecaBDE must report to
the Vermont Health Department. Washington prohibits the use of DecaBDE
in children's products, mattresses, electronics, and residential
furniture (Ref. 3).
    International actions on DecaBDE include Australia listing it as a
priority existing chemical, which requires the National Industrial
Chemicals Notification and Assessment Scheme (NICNAS) to fully assess
the human health and environmental risks of DecaBDE. The draft NICNAS
report on DecaBDE was completed in May 2019. Canada added DecaBDE to
its Prohibition of Certain Toxic Substances Regulation, which prohibits
the

manufacture, use, sale, offer for sale, or import of DecaBDE unless
present in a manufactured article. The European Member State Committee
has identified DecaBDE as a Substance of Very High Concern due to its
PBT chemical properties. The European Chemical Agency (ECHA) has
prohibited the manufacture and use of DecaBDE (including in most
articles at concentrations greater than 0.1% by weight) as of March
2019 under Annex XVII to the Registration, Evaluation, Authorisation,
and Restriction of Chemicals (REACH) regulation. DecaBDE is also listed
as a persistent organic pollutant (POP) under the Stockholm Convention,
which requires parties to take measures to eliminate production and use
of the chemical (Ref. 3).
    2. Phenol, isopropylated phosphate (3:1) (PIP (3:1). (i) Use
background: PIP (3:1) is used as a plasticizer, a flame retardant, an
anti-wear additive, and/or an anti-compressibility additive in
hydraulic fluid, lubricating oils, lubricants and greases, epoxy
coatings for decks of marine shipping vessels, coatings for pipes and
insulation in construction, adhesives and sealants for insulation, and
articles. For example, in lubricating oils, PIP (3:1) acts as a flame
retardant, an anti-wear additive, anti-compressibility additive, or
some combination of the three, while in adhesives and sealants PIP
(3:1) acts as a plasticizer and flame retardant (Ref. 4).
    PIP (3:1) has been identified as a possible component in plastic
products and articles, including children's products, automotive, and
aerospace products (Ref. 7).
    PIP (3:1) also is added to articles as a plasticizer or flame-
retardant additive in plastic components, adhesives and sealants, and
paints and coatings. Use of PIP (3:1) in complex articles (such as in
casings of electronics or components of automobiles), plastic articles
including furniture and furnishings, and toys intended for children's
use, has been identified (Ref. 7). PIP (3:1) is sold as a plastic
flame-retardant additive and is a component of some flame-retardant
additives for flexible polyurethane foam (Ref. 7). EPA is aware that
PIP (3:1) is used in antifouling paint; however, EPA does not consider
this a TSCA use because any pesticide, when manufactured, processed, or
distributed in commerce as a pesticide does not meet the definition of
``chemical substance'' under TSCA section 3. To ensure that this is
clear, EPA is proposing to incorporate the statutory definition of
``chemical substance'' into 40 CFR part 751, subpart E.
    EPA presented its initial research into PIP (3:1) uses in the
August 2017 Preliminary Information on Manufacturing, Processing,
Distribution, Use, and Disposal document on PIP (3:1) (Ref. 7). EPA
received comments from 15 entities on the Preliminary Information
document. EPA also communicated with companies, industry groups,
chemical users, states, and other stakeholders to identify and verify
uses of PIP (3:1) (Ref. 4). These interactions and comments further
informed EPA's understanding of the uses for PIP (3:1). Public comments
and stakeholder meeting summaries are available in EPA's docket at EPA-
HQ-OPPT-2016-0730.
    For the 2012 CDR period, data indicate that four sites manufactured
(including imported) PIP (3:1) in the United States. For the 2016 CDR
period, data indicate nine sites manufactured (including imported) PIP
(3:1) in the United States (Ref. 17). The total volume of PIP (3:1)
manufactured (including imported) in the United States was 14,904,236
lbs in 2011, 3,191,017 lbs in 2012, 2,968,861 lbs in 2013, 5,632,272
lbs in 2014, and 5,951,318 in 2015 (Ref. 17).
    (ii) What are the beneficial properties of PIP (3:1) for the
various uses? PIP (3:1) has multiple functional uses, including as a
plasticizer, flame retardant, anti-wear additive, or as an anti-
compressibility additive (Ref. 4). When PIP (3:1) is included in a
formula, it is often for a combination of these functional uses, for
example as flame retardant and an anti-wear additive. Additionally, PIP
(3:1) is an isomer mixture, and through manufacturing, the proportion
of various isomers can be manipulated to achieve specific properties
which can affect the performance of a formula (Ref. 21).
    PIP (3:1) is a component of additives to help lubricating oils and
hydraulic fluids meet safety and specific performance standards from
both military and industry, particularly in the aviation sector (EPA-
HQ-OPPT-2016-0730-0009) (Refs. 22, 23, 24, 25 and 26). It is present in
lubricating fluids which need to perform at extreme temperatures, both
hot and cold, as a flame retardant and anti-wear additive (Ref. 4).
Some lubricants containing PIP (3:1) are formulated to the military
performance specifications such as MIL-PRF-32014 for use in a
multipurpose, water resistant, high speed grease in a wide temperature
range (Refs. 22 and 23). In aviation hydraulic fluid, some phosphate
ester-based hydraulic fluids contain PIP (3:1) as a flame retardant,
anti-wear additive, and anti-compressibility additive. While multiple
hydraulic fluids meet industry performance standards for most
commercial and military airplanes, for some commercial models, the
information reasonably available to EPA indicates that only hydraulic
fluids containing PIP (3:1) can meet safety and air worthiness
standards. This includes those models which are designed to operate at
higher pressure systems, that is, 5,000 pounds per square inch (PSI) or
greater (Ref. 23, 24, and 25). For these systems, additives containing
PIP (3:1) allow the fluid to remain functional under this high pressure
at various temperatures and minimize wear in the hydraulic system
(Refs. 22, 23, 24 and 25).
    (iii) What are the 2014 TSCA Work Plan for Chemical Assessments
scores for PIP (3:1)? While not among the chemicals screened in 2012,
PIP (3:1) came to the Agency's attention as part of EPA's analysis of
flame-retardant chemicals and was subsequently scored using the TSCA
Work Plan Chemicals: Methods Document (Ref. 2) and added to the 2014
Update to the TSCA Work Plan for Chemical Assessments. PIP (3:1) scored
high (3) for hazard (based on neurotoxicity in mammals and aquatic
toxicity); high (3) for exposure (based on use as a flame retardant in
industrial and consumer products); and high (3) for persistence and
bioaccumulation (based on high environmental persistence and high
bioaccumulation potential). The overall screening score for PIP (3:1)
was high (9).
    (iv) Regulatory actions pertaining to PIP (3:1). PIP (3:1) is
regulated by federal, state, and international agencies. They are
briefly summarized in this unit. More detailed information can be found
in the Economic Analysis (Ref. 3). In addition, the OSHA regulations
discussed in Unit III.A. apply to commercial and industrial workplaces.
    PIP (3:1) was added to the Priority Testing List by the TSCA
Interagency Testing Committee in May 2012 (77 FR 30855). In addition, a
high-volume use of PIP (3:1) is in aviation and industrial hydraulic
fluid and lubricants and greases. If such fluids, lubricants, and
greases meet the definition of ``used oil'' under 40 CFR 279.1, they
are subject to Resource Conservation and Recovery Act (RCRA)
regulations for managing used oil (40 CFR part 279) (Ref. 3).
    With respect to state regulations, PIP (3:1) is listed as a
candidate chemical and identified as a potential priority monitoring
chemical in California, and Washington has identified PIP (3:1) as a
Chemical of High Concern to Children (Ref. 3).

    Internationally, PIP (3:1) is included in the ECHA Classification
and Labeling Inventory. The ECHA Classification and Labeling Inventory
is in line with the Globally Harmonized System of Classification and
Labeling of Chemicals (GHS); OSHA has also incorporated the GHS in its
Hazard Communication Standard. In Canada, PIP (3:1) was placed on the
Domestic Substance List (DSL) in 1994 as an Existing Substance not
subject to the New Substance Notification Regulations. The inclusion of
PIP (3:1) on the DSL designates it as an existing, rather than a new,
substance in Canada, the equivalent of being included on the TSCA
inventory as an active chemical (Ref. 3).
    3. 2,4,6-Tris(tert-butyl)phenol (2,4,6-TTBP). (i) Use background:
Uses of 2,4,6-TTBP include domestic manufacture, use as an
intermediate/reactant in processing, incorporation in formulations and
mixtures destined for fuel and fuel related additives, as well as
formulations intended for the maintenance or repair of motor vehicles
and machinery. Although EPA has not identified current users of 2,4,6-
TTBP for liquid lubricant and grease additives/antioxidants, it found
indications of current use, and a manufacturer has reported that, it is
aware that some customers may use its products for this end use,
although it does not actively market products with 2,4,6-TTBP for
lubricant applications. Therefore, the Agency proposes, for purposes of
this rulemaking, to address the use of 2,4,6-TTBP in liquid lubricant
and grease additives/antioxidants.
    2,4,6-TTBP is an alkylphenol whose primary value is as an
antioxidant. It is a widely used antioxidant for jet, automotive, and
marine fuels. Several stakeholders submitted comments to the public
docket following posting of the document, ``Preliminary Information on
Manufacturing, Processing, Distribution, Use, and Disposal: 2,4,6-
Tris(tert-butyl)phenol, August 2017'' (Ref. 8), which presented EPA's
initial research into the uses of 2,4,6-TTBP. One chemical processor
stated that they sell 2,4,6-TTBP as part of an antioxidant in fuel
additives for use in gasoline fuels with a concentration of one to 15%
2,4,6-TTBP; the gasoline fuels, after blending, are packaged and sold
in mild steel drums (55-gallon volume) or stainless-steel totes (350-
gallon volume) (EPA-HQ-OPPT-2016-0734-0015). The Aerospace Industries
Association also identified critical uses of 2,4,6-TTBP as a fuel,
lubricant, and oil additive/antioxidant in formulations designed to
meet specific technical performance requirements that are documented in
a number of engineering specifications over the service life of complex
aerospace products (EPA-HQ-OPPT-2016-0734-0010). The American Petroleum
Institute also confirmed that their members use 2,4,6-TTBP as an
antioxidant in gasoline, diesel, and aviation fuels at concentrations
of between 5 and 50 parts per million to reduce gasoline deposits in
engines and subsequently reduce emissions (EPA-HQ-OPPT-2016-0734-0006).
    Based on EPA's research and public comments submitted, the only
large volume domestic manufacturer, and the only manufacturer currently
reporting to the EPA's CDR with production volumes of 2,4,6-TTBP that
meet the CDR threshold, is SI Group. Historical CDR data indicate that
in the 1986 to 1998 reporting years, the aggregate range of production
of 2,4,6-TTBP was between 1 and 10 million pounds per year, and
increased to a range of 10 to 50 million pounds per year in reporting
years 2002 and 2006. The range of production in 2012, 2013, 2014, and
2015 was claimed as CBI in the 2016 CDR (Ref. 3). There have not been
any indications of substantial importation of 2,4,6-TTBP into the
United States from other countries.
    SI Group stated that proprietary chemical mixtures (primarily two,
Isonox[supreg] 133 and Ethanox[supreg] 4733) contain detectable
percentages of 2,4,6-TTBP and are used to meet several military
specifications for use in jet fuel that is supplied and used by the
U.S. military (Ref. 27). SI Group also stated that they do not sell,
supply, or distribute into commerce 2,4,6-TTBP in a pure (neat) form,
and none of their proprietary blended chemical mixtures containing
2,4,6-TTBP are sold directly to consumers; however, SI Group customers
use these mixtures to formulate other products containing 2,4,6-TTBP
that are intended for consumer applications (Ref. 27). SI Group also
stated that none of its proprietary chemical mixtures containing 2,4,6-
TTBP are actively marketed for use as a lubricant additive; however,
some of SI Group's customers may use the proprietary chemical mixtures
for this use (Ref. 27). SI Group also confirmed the sale of an excess
material stream containing 2,4,6-TTBP, that is used as a waste fuel for
energy value, which is burned and destroyed during use (Ref. 27).
    2,4,6-TTBP is a co-product with a closely related alkylphenol, 2,6
di(tert-butyl) phenol (2,6-DTBP), which is also a primary substitute
for it. Neither chemical can be effectively produced commercially
without co-production of the other. Approximately 94% of the 2,4,6-TTBP
produced by SI Group is consumed by the company in internal processes
(feedstock for further production of alkylphenols). An additional 4% is
sold as a waste fuel for energy use. Both uses result in the
destruction of the chemical.
    The remaining 2% of 2,4,6-TTBP produced by SI Group is sold as an
antioxidant primarily for use in fuel for all uses: Aviation, military,
industrial, commercial, and consumer use. The chemical is sold in a
mixture with its co-products, primarily 2,6-DTBP, at a concentration of
approximately 85% 2,6-DTBP and 12% 2,4,6-TTBP. The 2,4,6-TTBP is
destroyed when the fuel is consumed in the combustion process when the
fuel is burned (Ref. 8).
    Antioxidant additives are essential to the storage and transport of
fuel, as without them, fuel quickly begins to degrade and form harmful
sludge and varnish. The 2,4,6-TTBP mixtures are the primary
antioxidants used in aviation, marine, and automotive fuel streams in
the United States. Many current performance specifications for fuel
require their use; including for specialty fuels for aviation and the
military. The majority of the 2,4,6-TTBP mixtures sold are blended into
the fuel at the refinery or soon after at tank farms prior to
commercial distribution of the fuel.
    A portion (approximately 6%) of the 2,4,6-TTBP mixtures are sold to
processors who blend and distribute antioxidant products that are
intended to be added to the fuel tanks/systems in vehicles or machinery
by repair shops or the owner/operators of the equipment themselves.
These fuel stabilizer products are sold to consumers at various retail
locations, as well as online. These additives are typically sold in
small bottles containing up to 32 ounces; gallon containers are
available through some retailers. Specialty products are also sold for
cleaning fuel injectors or use in 2-stroke engines (pre-blended with
oil).
    Other countries have reported that 2,4,6-TTBP is, or has been, used
as an additive in oils and lubricants (EPA-HQ-OPPT-2016-0734-0002). SI
Group states that it does not actively market products containing
2,4,6-TTBP for lubricant applications, but that it is aware that some
customers may use these products in lubricant applications (Ref. 27).

    (ii) What are the beneficial properties of 2,4,6-TTBP for various
uses? Regarding the benefit of manufacture, beyond its use as an
antioxidant, 2,4,6-TTBP has value as a chemical intermediate in the
production of dialkylphenol chemicals. Moreover, SI Group reports it is
not possible to significantly suppress the formation of 2,4,6-TTBP
without severely constraining the yield of other desired dialkylphenol
products, therefore its manufacture has impacts beyond the commercial
use of 2,4,6-TTBP itself. The production of other dialkylphenol
products, including alternative antioxidants, is therefore a benefit of
ongoing 2,4,6-TTBP manufacture.
    With respect to use as an antioxidant in the general fuel supply,
EPA has received comment regarding the beneficial properties of 2,4,6-
TTBP as an antioxidant component blended in fuel. SI Group identified
numerous U.S. military and ASTM standards that its proprietary blended
products containing 2,4,6-TTBP satisfy for the antioxidant requirements
in fuel (Ref. 27). Although particular specifications do not list
2,4,6-TTBP by CASRN or trade name, 2,4,6-TTBP is the preferred
antioxidant component for fuel standards due to its chemical reaction
potential and physical property characteristics (Refs. 27 and 28).
According to the manufacturers and processors, any substitution of
2,4,6-TTBP with another alkylphenol or antioxidant compound would
materially change the performance characteristics of that fuel and
compliance with mandatory reference standards could not be assured
(Ref. 28). Introducing a new jet fuel component into use involves the
fuel component supplier, engine manufacturers, airplane makers and
regulators in a complicated process that may take several years and
involve significant cost. New fuel additives must be tested and
approved to ensure they would have no negative impact on engine safety,
durability or performance (Ref. 27).
    Regarding the retail sale of fuel additives and fuel injector
cleaners, EPA was unable to find any specifications or standards for
retail fuel antioxidants or additives that explicitly require the use
of 2,4,6-TTBP.
    Regarding the use of 2,4,6-TTBP as an antioxidant additive in oil
and lubricants, EPA was unable to find any specifications or standards
for oil, lubricant, or grease additives that require the use of 2,4,6-
TTBP.
    (iii) What are the 2014 Updates to the TSCA Work Plan for Chemical
Assessments scores for 2,4,6-TTBP? 2,4,6-TTBP scored moderate (2) for
hazard (based on toxicity following chronic exposure including liver
effects); moderate (2) for exposure (based on its wide use in consumer
products, presence in indoor environments, and estimation to have
moderate releases to the environment); and high (3) for persistence and
bioaccumulation (based on moderate environmental persistence and high
bioaccumulation potential). The overall screening score for 2,4,6-TTBP
was high (7).
    (iv) Regulatory actions pertaining to 2,4,6-TTBP. EPA has no
existing regulations expressly identifying 2,4,6-TTBP, and EPA did not
identify any existing or developing Federal regulations for 2,4,6-TTBP.
However, the OSHA regulations discussed in Unit III.A. apply to
commercial and industrial workplaces.
    With respect to state regulations, the California Department of
Toxic Substances Control (DTSC) lists 2,4,6-TTBP as a Candidate
Chemical. A Candidate Chemical must exhibit a hazardous trait and/or an
environmental or toxicological endpoint and is found on an
authoritative list under California Code of Regulations section
69502.2(a) or is listed by DTSC using criteria specified in section
69502.2(b) (Ref. 3). In Oregon, 2,4,6-TTBP is listed on Oregon
Department of Environmental Quality's pollutant profiles (Ref. 3) and
2,4,6-TTBP is listed as a tier 1 persistent pollutant (Ref. 3). With
respect to international actions, Japan has prohibited the importation,
manufacture, and use of 2,4,6-TTBP as a Class 1 Specified Chemical
under the Chemical Substance Control Law (Ref. 3).
    Environment Canada's 2008 screening assessment for 2,4,6-TTBP
concluded that 2,4,6-TTBP may be entering the environment and meets the
criteria set out in section 64 of the Canadian Environmental Protection
Act of 1999. Environment Canada has since completed a risk evaluation
and in 2016 recommended 2,4,6-TTBP be added to schedule 1 of the
environmental emergency regulations, at a threshold quantity of 0.22
tonnes at a concentration of 10%; listing may require persons who own
or manage specified toxic and hazardous substances at or above the
specified thresholds to provide required information on the
substance(s) and their quantities and to prepare and implement
environmental emergency plans (Ref. 3).
    2,4,6-TTBP is on the European Chemical Agencies (ECHA)
Classification and Labeling inventory and the European community
inventory. More detailed information on the state and international
regulations pertaining to 2,4,6-TTBP can be found in the Economic
Analysis (Ref. 3).
    4. Hexachlorobutadiene (HCBD). (i) Use background: HCBD is a
halogenated aliphatic hydrocarbon that is produced as a byproduct
during the manufacture of chlorinated hydrocarbons, particularly
perchloroethylene, trichloroethylene, and carbon tetrachloride (Ref.
29). The majority of what is manufactured is destroyed via incineration
by the manufacturer. A small percentage of the HCBD is sent off-site
for incineration or for burning as a waste fuel by cement manufacturers
in cement kilns (EPA-HQ-OPPT-2016-0738-0012). EPA has not identified
any uses of HCBD other than burning as a waste fuel. According to TRI
data, over 9 million lbs of HCBD were generated by chemical
manufacturers in reporting year 2017, with almost 8.9 million lbs
treated for destruction on-site via incineration. TRI reports show
other waste management activities of HCBD including 58,000 lbs being
treated for destruction off-site, 33,000 lbs burned for energy recovery
off-site, and 2,400 lbs released to air.
    (ii) What are the beneficial properties of HCBD for the various
uses? HCBD is manufactured as a waste byproduct by chemical
manufacturers. The majority of what is manufactured is destroyed via
incineration by the manufacturer. A small percentage of the HCBD is
sent off-site for burning as a waste fuel by cement manufacturers.
    (iii) What are the 2014 Update to the TSCA Work Plan for Chemical
Assessments scores for HCBD? HCBD scored high (3) for hazard (possible
human carcinogen); moderate (2) for exposure (based on TRI data); and
high (3) for persistence and bioaccumulation (based on high
environmental persistence and high bioaccumulation potential). The
overall screening score for HCBD was high (8).
    (iv) Regulatory actions pertaining to HCBD. Under EPCRA, HCBD has
been listed on the TRI list of reportable chemicals since 1988 (Ref.
20). HCBD is a Hazardous Air Pollutant (HAP) under section 112 of the
Clean Air Act (CAA) as amended in 1990. The Agency has promulgated
National Emission Standards for Hazardous Air Pollutants (NESHAPs)
which require the maximum achievable control technology (MACT) for
major sources in Standard Source Categories. Under the Clean Water Act
(CWA), HCBD is listed on the Priority Pollutant List and is subject to
Effluent Guidelines and the requirements of the National Pollutant
Discharge and Elimination System (NPDES). Under the

Resource Conservation and Recovery Act (RCRA), HCBD is a hazardous
constituent and can be characterized as a toxicity characteristic waste
(Hazardous Waste No. D033) or listed hazardous waste (U128) under RCRA
when discarded or intended for discard. Under the Comprehensive
Environmental Response, Compensation and Liability Act, HCBD is
designated as a hazardous substance with a reportable quantity (RQ) of
1 lb. More information on the impact of these existing regulations is
in Unit III.E.
    With respect to other Federal regulations, the Pipeline and
Hazardous Material Safety Administration in the Department of
Transportation lists HCBD as a hazardous substance with a reportable
quantity of 1 lb. In addition, the OSHA regulations discussed in Unit
III.A. apply to commercial and industrial workplaces.
    Many states have promulgated regulations applicable to HCBD. State
requirements concerning HCBD include regulations of water quality
standards, sources of air pollution and management of waste containing
the chemical. The following states implemented water quality standards
for HCBD: Arizona, California, Colorado, Connecticut, Delaware,
Florida, Georgia, Hawaii, Idaho, Indiana, Kentucky, Louisiana, Maine,
Maryland, Michigan, Missouri, Montana, Nebraska, New Hampshire, New
Jersey, New Mexico, New York, North Carolina, North Dakota, Oregon,
Pennsylvania, Rhode Island, South Carolina, South Dakota, Tennessee,
Texas, Utah, Vermont, Virginia, Washington and Wisconsin. Several
states have air pollution requirements for HCBD including Idaho,
Illinois, Maryland, New Hampshire and Ohio.
    Internationally, Austria banned the use of HCBD in 1992 citing its
carcinogenic and mutagenic properties as well as fetotoxicity and
negative effects on fertility. In Canada, HCBD is on the Domestic
Substance List (DSL) as an Existing Substance not subject to the New
Substance Notification Regulations. It was also added to Schedule 1 of
the Canadian Environmental Protection Act and to Schedule 1 of the
Prohibition of Certain Toxic Substances Regulations. HCBD was also
placed on Canada's Virtual Elimination List. In China, HCBD is in the
Catalog of Hazardous Chemicals. In the European Union (EU), HCBD is
listed on the Annex III inventory based on its bioaccumulative
properties and is subject to Annex V Part 1 of Prior Informed Consent
(PIC) Regulation. In Germany, HCBD is on the Master List of the German
Federal Environment Agency (UBA). Under the Chemical Substances Control
Law of Japan, HCBD was designated a Class I Chemical Substance. Swedish
Chemicals Agency includes HCBD on a list of phase-out substances. The
United Kingdom regulates HCBD through several mechanisms including the
Pollution Prevention and Control regulations, the Food and
Environmental Protection Act, and the Control of Pesticides
Regulations.
    Under the Stockholm Convention, HCBD is listed as a persistent
organic pollutant (POP) under Annex A which requires parties take
measures to eliminate production and use of the chemical, and under
Annex C which requires parties to reduce the unintentional releases of
chemicals.
    For more information about regulatory actions pertaining to HCBD,
see the Economic Analysis for this proposed rule (Ref. 3).
    5. Pentachlorothiophenol (PCTP). (i) Use background: Historically,
PCTP was used in rubber manufacturing as a peptizer, a chemical that
makes rubber more amenable to processing. There are few data, however,
on end-use products that contain PCTP. For years, PCTP was produced in
the United States but domestic manufacture appears to have ceased (Ref.
17). While it is likely that PCTP is no longer used as a peptizer, it
can be found as an impurity in the zinc salt of PCTP (zinc PCTP) (CASRN
117-97-5) after zinc PCTP manufacturing (Ref. 30). As shown by a number
of patents, zinc PCTP can be used as a peptizer in rubber manufacturing
and as an ingredient in the rubber core of golf balls to enhance
certain performance characteristics of the ball, such as spin, rebound,
and distance (Refs. 31 and 32). EPA considers the addition of PCTP to
rubber during manufacturing, whether as a peptizer or an impurity, to
be processing under TSCA.
    Zinc PCTP is imported into the United States, with approximately
65,000 lbs imported in 2017 (Ref. 3). EPA believes that some or all of
the zinc PCTP could contain PCTP. The importation of PCTP, including as
an impurity with zinc PCTP, is considered manufacturing under TSCA. EPA
requests comments as to which chemicals would most likely serve as
alternatives to ZnPCTP in golf balls, and why golf ball manufacturers
may not currently choose to use these alternatives.
    (ii) What are the beneficial properties of PCTP for various uses?
During the manufacture of rubber, PCTP was used as a peptizer to reduce
the viscosity of rubber during processing. PCTP has been used as a
mastication agent in the rubber industry and, more specifically, a
peptizing agent for natural rubber viscosity reduction in the early
stages of rubber manufacturing (Ref. 33). Mastication and peptization
are processing stages during which the viscosity of rubber is reduced
to a level facilitating further processing (Ref. 34). It is possible to
reduce the viscosity of natural and synthetic rubbers through solely
mechanical efforts, but peptizers allow this process to be less
sensitive to varying time and temperature, which improves the
uniformity between batches (Ref. 33).
    (iii) What are the 2014 Update to the TSCA Work Plan for Chemical
Assessments scores for PCTP? PCTP scored high (3) for hazard (based on
toxicity for acute and chronic exposures); low (1) for exposure (based
on 2012 CDR data); and high (3) for persistence and bioaccumulation
(based on high environmental persistence and high bioaccumulation
potential). The overall screening score for PCTP was high (7).
    (iv) Regulatory actions pertaining to PCTP. PCTP was added to the
TSCA Preliminary Assessment Information Rule (PAIR) Priority Testing
List in August 2001 (Ref. 35). The PAIR requires manufacturers
(including importers) of the substances identified to report certain
production, importation, use, and exposure-related information to EPA.
PCTP was removed from the Priority Testing List in 2003 because of low
exposure potential (Ref. 36). In addition, the OSHA regulations
discussed in Unit III.A. apply to commercial and industrial workplaces.
    With respect to state regulations, California's Department of Toxic
Substances Control includes PCTP on its Candidate Chemical list based
on its bioaccumulation, environmental persistence, and toxicity. Maine
includes PCTP on its list of Chemicals of High Concern. Maryland lists
PCTP as a Toxic Air Pollutant. The Minnesota Department of Health lists
PCTP as a Chemical of High Concern for its PBT properties (Ref. 3).
    With respect to international actions, in Canada, PCTP is on the
Domestic Substance List (DSL) as an ``Existing Substance'' as it met
the criteria under subsection 73(1) of the Canadian Environmental
Protection Act, 1999 (CEPA), because it was already in commerce in
Canada from 1984 to 1986 and thus not subject to the New Substance
Notification Regulations. In 2008, PCTP was moved to Part 2 of the DSL
to indicate that it is subject to a Significant New Use Activity under
subsection 81(3) of CEPA. In the European Union, PCTP is listed on the

Annex III inventory based on its bioaccumulative properties and, in
Japan, PCTP is listed as an Existing Chemical under the Chemical
Substances Control Law (CSCL). More information on the Federal, state
and international regulations pertaining to PCTP can be found in the
Economic Analysis (Ref. 3).

E. Exposure and Use Assessment and Hazard Summary

    1. Summary of the Exposure and Use Assessment. An exposure and use
assessment was conducted for the five PBT chemicals using the following
information: (a) Chemical and physical-chemical properties, (b) use
descriptions, (c) expected environmental partitioning, (d) lifecycle
and potential sources, (e) environmental monitoring, (f) biomonitoring,
(g) modeled intake and doses from existing studies, (h) trends in the
data, (i) summary information from completed exposure assessments and
review of peer-review articles published at the time of preparation of
the exposure and use assessment, (j) representative exposure scenarios,
and (k) information provided by public comment and peer review. This
information helps to identify potential exposure scenarios that are the
combination of sources/uses, environmental pathways, and receptors.
    Lifecycle diagrams were developed and qualitative evaluations
describing relative potential for occupational exposure of the five PBT
chemicals were performed to assess release to different media from
various industrial operations. Though environmental partitioning of
chemicals in various media were considered, uses and processes for each
of these five PBT chemicals have variations of releases in different
media. A comprehensive literature search was performed to collect
environmental and bio-monitoring information to assess the likely
exposure of the general population, consumers, occupational
populations, potentially exposed or susceptible subpopulations, and the
environment from the conditions of use of the PBT chemicals.
    Only a few monitoring studies were reported for PIP (3:1) and
2,4,6-TTBP. Thus, a supplemental search was conducted to identify
closely related chemicals. Based on EPA scientific review and
evaluations, triphenyl phosphate (TPP) and 2,4-di-tert-butylphenol
(2,4-DTBP) were considered as surrogate chemicals for PIP (3:1) and
2,4,6-TTBP, respectively. These surrogates were selected based on
availability of data, structural similarity, similar use, and
reasonably close physical-chemical properties. PCTP was also found to
have limited data; however, no surrogate chemicals were identified for
PCTP using these criteria.
    Multiple approaches were considered to construct non-specific
exposure scenarios. Comparison of exposure scenarios revealed source
attribution. The relative complexity of source attribution varied
depending on the continuum of available uses/sources and the media
considered. For example, total dust concentrations in a residence
represent contributions from multiple sources. Similarly, internal dose
measured in biota represents total exposure from multiple media and
sources. This source attribution can be qualitative or quantitative.
Qualitative descriptors (e.g., higher, lower potential for exposure)
were used to characterize exposures, and uncertainties were
acknowledged across the exposure scenarios.
    2. Proposed TSCA section 6(h)(1)(B) exposure finding. In this unit
EPA provides an overview of the potential exposures for each PBT
chemical. The possible exposures are described within the context of
the lifecycle of the chemical, e.g., exposures during manufacturing,
processing, distribution, use and disposal. However, EPA notes that
these exposures are possible, not necessarily probable nor known. This
is especially so in instances where regulatory controls mandated by
other statutes are applicable. As discussed in Unit III.A., EPA
generally expects there is compliance with Federal and state laws, such
as worker protection standards or disposal restrictions, unless case-
specific facts indicate otherwise.
    EPA is proposing to determine in accordance with TSCA section
6(h)(1)(B) that, based on the Exposure and Use Assessment and other
reasonably-available information, exposure to the five PBT chemicals
under the conditions of use is likely to the general population, to a
potentially exposed or susceptible subpopulation, or the environment,
which is the threshold for expedited action under TSCA section 6(h).
EPA's proposed determination is based on the opportunities for exposure
throughout the lifecycle of each of the five PBT chemicals including,
for some, consumer exposures.
    (i) DecaBDE. Exposure information for DecaBDE is summarized here
and is detailed in EPA's Exposure and Use Assessment (Ref. 4).
    The most likely sources of releases and occupational exposures
during the manufacturing condition of use of DecaBDE are associated
with fugitive dust. These include air releases from transfer and
packaging operations (fugitive dust to ambient air, as well as dust
that is collected and channeled through a dedicated point as a stack
release) and solid waste from floor sweepings, disposal of used
transfer containers containing residual DecaBDE, and liquid waste from
equipment cleaning. Fugitive vapor air releases are not expected due to
the chemical's low vapor pressure. Releases to land are possible when
floor sweepings and other solid waste are collected and disposed in
landfills. Similarly, the collection and disposal of liquid equipment
cleaning solutions has the potential of generating liquid waste
containing DecaBDE (aqueous waste to surface waters and sent to
publicly owned treatment works, and organic waste collected and sent
for other disposal or waste treatment such as incineration). Historical
and recent TRI data confirm primary releases are to air, followed by
landfill and water (Ref. 4). As noted previously, under TRI, a release
of a chemical means that it is emitted to the air or water, or placed
in some type of land disposal. These releases may be regulated under
other environmental statutes, such as the CAA, CWA, or RCRA.
Occupational exposures from inhalation and dermal exposure to dust are
possible during transfer and packaging operations and from fugitive
dust emissions from process operations if workers are unprotected. The
OSHA regulations discussed in Unit III.A. apply to industrial and
commercial workplaces. More specifically, the OSHA regulations at 29
CFR 1910.132 require employers to assess a workplace to determine if
hazards are present or likely to be present which necessitate the use
of personal protective equipment (PPE). If the employer determines
hazards are present or likely to be present, the employer must select
the types of PPE that will protect against the identified hazards,
require employees to use that PPE, communicate the selection decisions
to each affected employee, and select PPE that properly fits each
affected employee. Thus, EPA would not expect workers in industrial and
commercial workplaces to be unprotected.
    During processing conditions of use, DecaBDE is combined with other
ingredients (e.g., monomers) and then molded, extruded, formed into
final products, or applied to a finished article, where curing may
occur (Ref. 4). Releases to air, land, and water may occur from DecaBDE
and DecaBDE

flame-retardant formulations (solids and liquids), as well as from off-
specification products containing the additive flame retardant. Air
releases (fugitive dust and dust collected and channeled to a stack)
may occur from transfer operations. Releases to land may occur during
disposal of transfer containers containing residual material,
collection and disposal of floor sweepings, and disposal of off-spec
product. Equipment and general area cleaning with aqueous cleaning
materials may result in releases to water. Current and historical TRI
data indicate the primary releases are to air, followed by landfill and
water (Ref. 4). Occupational exposures from inhalation and dermal
exposure to dust may occur during transfer and packaging operations and
from fugitive dust emissions from process operations if workers are
unprotected. Dermal exposure to liquids is possible from incidental
contact of liquid flame-retardant formulations containing DecaBDE
during transfer, loading, and mixing operations. Occupational exposures
may occur when the bags of flame retardant are emptied into a hopper
prior to mixing if workers are unprotected. Once formulated, DecaBDE is
encased in the polymer matrix and the potential for worker exposure is
reduced significantly (Ref. 4).
    DecaBDE is present in plastic that may be recycled and subsequently
reused. Releases from recycling facilities may occur from discarded
material that cannot be recycled and reclaimed and is disposed in
landfills. Releases to air and water are expected to be minimal during
most recycling processes because DecaBDE is entrained in the articles
and is not expected to volatize or migrate readily from the facility
during recycling operations. However, there is potential for
volatilization and releases to air if recycling involves heating and
melting the DecaBDE-containing plastic article, and, thus, inhalation
exposures if workers are unprotected. Limited occupational exposure to
workers at recycling facilities is possible from dermal contact during
handling of plastic material that is received and introduced into
recycling operations, and from inhalation exposure to dust from
grinding and shredding operations, if workers are unprotected.
    DecaBDE is combined with other ingredients and incorporated into
the back coating of various textiles, such as curtains, via roll or dip
coating processes. Releases may occur from disposal of transfer
containers associated with DecaBDE formulations, disposal of waste from
equipment and area cleaning, disposal of off-spec product, and disposal
of bath dumps. Historical TRI data indicate most releases during this
processing activity are associated with disposal to landfills, with
smaller quantities released to air, and with minimal releases to water.
If workers are unprotected, inhalation exposures may occur due to:
Fugitive dust generated from unloading and transfer of the solid flame
retardant into mixing vessels; mist generated from the squeezing of the
immersed fabric with rollers; from the roll coating application during
back coating; and, after the coating operations are complete, during
fabric cutting. If workers are unprotected, dermal exposures to solid
and liquid DecaBDE mixtures in fabric finishing may occur from
unloading operations, mixing finishing baths, equipment cleaning, and
spilling (Ref. 4).
    DecaBDE is combined with other ingredients and then molded,
extruded, formed into final products, or applied to wire or cable (Ref.
4). Releases may occur from transfer operations, volatilization from
extrusions, disposal of transfer containers, waste from equipment and
area cleaning, and disposal of off-spec product. Historical TRI data
indicate most releases during this processing activity are associated
with disposal to landfills, with smaller quantities released to air,
and with minimal or no releases to water (Ref. 4). If workers are
unprotected, inhalation exposure from fugitive dust that is generated
from unloading and transfer of the flame retardant into mixing vessels
and from vapors generated during extrusion may occur. If workers are
unprotected, dermal exposure is most likely during formulation when the
bags of flame retardant are emptied into a hopper prior to mixing. Once
formulated, DecaBDE is encased in the cured coating and the potential
for worker exposure is minimal.
    Article components containing DecaBDE, such as fabrics and plastic
parts, are incorporated into finished products, such as automobiles and
aircraft. Releases to land may occur from disposal of off-spec products
that contain DecaBDE. Releases to air and water are expected to be
minimal because DecaBDE is entrained in the articles and is not
expected to volatize or migrate readily under normal use. Occupational
exposure from dermal contact with article components during
installation is possible if workers are unprotected. Inhalation
exposure is not expected due to the low potential for volatilization.
    Articles treated with DecaBDE are used in the home, in business
settings, and in the transportation sector. DecaBDE has also been found
in children's products such as plastic play structures and toys, though
DecaBDE is present only in low (below 0.1%) concentrations in many
cases. DecaBDE is also found in plastics used as components in
electrical appliances and equipment such as stereos, computers,
televisions, circuit boards, casings, and cable insulation. Other uses
in the transportation and construction sector are in the fabrics of
automobiles, aircrafts, and in building materials (Ref. 4). DecaBDE's
primary use is in high impact polystyrene-based products that are used
in plastics, specifically in plastic enclosures for televisions,
computers, and audio and video equipment. It is also used in textiles
and upholstered articles (including carpets, upholstery fabric,
curtains, and cushions), and wire and cables for communications and
electronics (Refs. 4 and 6). The quantity of DecaBDE in these articles
is unknown. Releases from these articles may occur when DecaBDE
migrates from the articles during use (e.g., in homes and business
settings), disposal, and waste management. Occupational dermal
exposures are expected to be minimal from handling and repackaging
articles. Inhalation and dermal exposures are possible during recycling
operations if workers are unprotected (e.g., recycling of plastics)
(Ref. 4). The end-of-life disposal and waste handling options for
products containing DecaBDE include disposal in landfills, recycling
and incineration (Ref. 4).
    Exposure assessments on DecaBDE have been conducted by the EPA
(including industry-supplied information as part of the Voluntary
Children's Chemical Evaluation Program), the National Academy of
Sciences, and international governments. These assessments describe
exposure potential for PBDEs, including DecaBDE, through a variety of
pathways. Adult and child exposures occur via dust ingestion, dermal
contact with dust, and dietary exposures (such as dairy consumption).
Household consumer products have been identified as the main source of
PBDEs (including DecaBDE) in house dust. The next highest exposure
pathways included dairy ingestion, and inhalation of indoor air (via
dust). Infant and child exposures occur via breastmilk ingestion and
mouthing of hard plastic toys and fabrics. Occupational exposures for
breastfeeding women were highest in women engaged in activities
resulting in direct contact with DecaBDE (Ref. 4).
    Experimental product testing studies suggest that DecaBDE can be
emitted from articles during use through

abrasion and direct transfer to dust on surfaces. Based on DecaBDE's
physical-chemical properties, ingestion of settled dust through routine
hand-to-mouth and object-to-mouth contact is likely the primary
exposure route for articles. The inhalation pathway also contributes to
exposure when suspended particles deposited in the upper airway are
subsequently swallowed. The dermal pathway likely contributes a smaller
proportion of total exposure.
    Numerous monitoring studies have shown that DecaBDE has been
detected in a wide variety of media such as indoor dust, air, water,
soil, human blood, and fish. Dietary exposure through the food-chain
and trophic transfer may contribute to presence in biological matrices
(human blood, fish, etc.).
    Exposure to ecological receptors has been well documented, with
several biomonitoring studies reporting levels in tissues of
invertebrates, fish, and birds (Ref. 4). Environmental and biological
levels are typically higher near point sources. However, DecaBDE has
also been detected in remote areas indicating potential for long-range
transport.
    DecaBDE was produced and released at higher levels in the past but
continues to be released. Releases from manufacturing and processing
are declining over time, as are releases associated with use, disposal,
and recycling (Ref. 4).
    (ii) PIP (3:1). As discussed briefly in Unit II.D.2, PIP (3:1),
CASRN 68937-41-7 is a mixture of isomers. The proportion of various
isomers within a mixture is often proprietary, and can affect the
performance of the product, as well as its hazard and ecological
persistence and bioaccumulation. Most of the existing studies of PIP
(3:1) represent exposures to whole commercial products; however, the
amount of PIP (3:1) within the studied formula varies greatly in
content and propylation configurations. In these studies, exposure to
other chemicals within the product, such as triphenyl phosphate, which
is often present in mixtures of PIP (3:1) in concentrations from 5-10%,
may influence the magnitude of exposure to PIP (3:1) from commercial
products, and the effects observed.
    Exposure information for PIP (3:1) is briefly summarized here and
is detailed in EPA's Exposure and Use Assessment (Ref. 4).
    PIP (3:1) is manufactured, processed, distributed, and used
domestically. There is potential for exposure to PIP (3:1) under the
conditions of use at all stages of the lifecycle (i.e., manufacturing,
processing, use (industrial, commercial, and consumer), distribution,
and disposal) of the chemical (Ref. 4).
    During the manufacturing condition of use, fugitive air releases
from various process steps, water releases from separation and drying
steps as well as equipment and area cleaning, and land releases from
disposal of spent filters are possible.
    During the processing into formulas conditions of use, releases to
air, water, and land are possible from the associated unit operations.
The primary sources of release include container residue, process
equipment cleaning, and disposal of off-spec products.
    PIP (3:1) is an additive flame retardant that is used in a variety
of articles including plastic resins, foam, and synthetic rubber. Flame
retardants in general are incorporated into products in one of two
manners. They are either chemically bound to the product matrix as
``reactive'' mixtures, or they are dissolved in the polymer materials
as ``additives.'' Additive flame retardants are not chemically bound
and are relatively unattached to the polymer matrix. Therefore, they
have the increased potential of migrating from products to the
surrounding environment during normal use.
    Fugitive air releases of PIP (3:1) are expected to be minimal due
to its low vapor pressure. Water and land releases are not expected
from waste hydraulic fluids and greases because used fluids and grease
are typically collected for reuse or incineration (Ref. 4).
    If workers are unprotected, dermal exposure to PIP (3:1) (full or
partial hand immersion, splashing, or spraying) is possible from
handling hydraulic fluids and lubricants and greases. Inhalation
exposure to fugitive vapors is expected to be minimal, but inhalation
exposure to mist is possible if the fluid is spray-applied and if
workers are not wearing appropriate personal protective equipment.
Transportation workers, aside from those who regularly handle these
fluids, can also be exposed to hydraulic fluid vapor; for example,
airline crews can be exposed to hydraulic or engine oil smoke or fumes
(Ref. 4).
    PIP (3:1) is also added to coatings, adhesives, and sealants for a
variety of industrial uses. Potential application methods of these
coatings to industrial substrates may include roll, dip, and spray
processes. The quantity of releases and level of occupational exposures
varies with each process; however, each presents possible releases to
all media (air, water, land) and exposures (inhalation of vapors or
mists and dermal exposure to liquids).
    While release of PIP (3:1) is possible, the data on PIP (3:1)
pathways and endpoints are limited, even when looking at an analogue
like triphenyl phosphate. The reasonably available data are generally
consistent with the fate summary and reported physical-chemical
properties in that PIP (3:1) was detected in indoor dust, soil, ambient
air, and sediment in higher concentrations and was not reported in
other media.
    Triphenyl phosphate, or TPP, is used as an analogue for PIP (3:1)
in EPA's Exposure and Use Assessment. TPP is present in formulated
products with PIP (3:1), sometimes in concentrations of 5-10%. The
larger body of TPP data provides insight into the expected patterns of
environmental partitioning and uptake of PIP (3:1), but not as being
indicative of the levels of PIP (3:1) that should be expected or the
toxicity of PIP (3:1). In the literature search, information was
identified showing that TPP or its metabolites were detected or
estimated in human blood, dermal wipes, fish, terrestrial
invertebrates, birds, and terrestrial mammals.
    (iii) 2,4,6-TTBP. Exposure information for 2,4,6-TTBP is briefly
summarized here and is detailed in EPA's Exposure and Use Assessment
(Ref. 4)
    Fuel additive formulations containing 2,4,6-TTBP in solution may be
shipped to end users in a variety of container types. Fugitive air
releases of 2,4,6-TTBP are expected to be minimal (due to the low vapor
pressure) from unloading and transfer operations. It is expected that
the majority of 2,4,6-TTBP is destroyed (burned) as the fuel it is
added to is consumed. Releases may occur from disposal of empty
transport containers and waste absorbents used to clean spills and
leaks from loading operations. Waste from equipment cleaning with
organic cleaning solutions is anticipated to be collected for
incineration. Water releases are possible from equipment and general
area cleaning with aqueous cleaning solutions. Dermal exposure to
2,4,6-TTBP to workers may occur from transfer and fuel loading
operations. Dermal exposure resulting from manufacturing and processing
conditions of use at manufacturing facilities and fuel production
facilities is expected to be minimal due to the use of appropriate
engineering controls and personal protective equipment (PPE). At the
manufacturer facilities, worker PPE consists of nitrile gloves,
chemical-resistant slicker suits, chemical resistant boots, respirators
with face shield and hard hats; workers are trained and

monitored in the correct use of their PPE. Sampling during production
is accomplished using controlled sampling spigots, which prevent
aerosol formation, splashing and spillage, minimizing potential worker
exposure. Controlled sampling spigots are also used for transfer
activities (loading and unloading) (EPA-HQ-OPPT-2018-0314-0018).
Refineries, fuel distribution and fuel storage facilities also operate
with appropriate engineering controls, PPE, working worker training,
leak detection and spill control measures; vapor recovery systems are
used during distribution and storage (EPA-HQ-OPPT-2016-0734-0006). Once
blended into fuel, the resultant concentration of 2,4,6-TTBP in fuel is
low, in the 5 to 50 ppm range, limiting the exposure resulting from
handling and spills or leaks.
    Use of retail fuel additive products which are sold in small
containers by mechanics and consumers to service cars, boats, small
engines, etc., present opportunities for release and dermal exposure
during transfer activities if workers are unprotected. Spillage may
occur when the product is being pouring into fuel tanks and storage
cans. Product containers may also leak during transportation, handling,
storage and disposal. Used containers are disposed of in the municipal
solid waste stream without special handling.
    If released to the indoor environment, 2,4,6-TTBP could partition
to particulates and dust based on its chemical relationship with
organic carbon compared to that of air. If released into a sanitary
sewer system or storm water system, 2,4,6-TTBP would likely transport
to nearby wastewater treatment plants due to relative mobility in water
due to high water solubility and low KOC (soil organic carbon/water
partitioning coefficient).
    EPA did not identify any studies with extractable 2,4,6-TTBP data
in drinking water or any studies with detectable levels of 2,4,6-TTBP
in soil, sludge/biosolids, or vegetation/diet. Additionally, EPA did
not identify any studies with detectable levels of 2,4,6-TTBP in human
blood (serum), other human organs, aquatic invertebrates, aquatic
vertebrates, terrestrial invertebrates, birds, or terrestrial mammals.
    (iv) HCBD. Exposure information for HCBD is briefly summarized here
and is detailed in EPA's Exposure and Use Assessment (Ref. 4).
    HCBD is manufactured as a byproduct by chemical manufacturing
facilities. Most of the chemical is destroyed by incineration with a
small percentage released to air via stack and fugitive emissions.
Waste containing HCBD is blended with conventional fuels and burned in
cement kilns for energy recovery. EPA has not identified any uses of
HCBD other than burning as a waste fuel. The destruction and removal
efficiency from incineration of HCBD is expected to be significant but
not complete, resulting in air releases from incinerator flue gas and
land releases from disposal of ash and slag. Minor water releases from
equipment cleaning are possible (Ref. 4).
    Multiple studies show that HCBD has been detected in a wide variety
of media. Higher concentrations were reported in ambient air, surface
water, soil, and sediment. Lower concentrations were reported in
drinking water, indoor air, and sludge/biosolids. TRI data show that
HCBD is released to air annually from chemical manufacturers, with
approximately 2,400 lbs released in 2017. TRI data indicate that the
number of reporting facilities and the total domestic release
quantities to all media have remained relatively constant since 2000
(Ref. 7).
    (v) PCTP. Exposure information for PCTP is briefly summarized here
and is detailed in EPA's Exposure and Use Assessment (Ref. 4).
    Since PCTP is a dry powder, the most likely sources of releases and
occupational exposures from the manufacturing condition of use are
associated with fugitive dust, if workers are unprotected. These
include air releases from transfer and packaging operations (fugitive
dust to ambient air as well as dust that is collected and channeled
through a dedicated point as a stack release) and solid waste from
floor sweepings, disposal of used transfer containers containing
residual PCTP, and liquid waste from equipment cleaning. Fugitive vapor
air releases are not expected due to the low vapor pressure. Releases
to land are possible when floor sweepings and other solid waste are
collected and disposed in landfills. Similarly, the collection for
disposal of liquid equipment cleaning solutions has the potential of
generating liquid waste containing PCTP (aqueous waste to surface
waters and sent to publicly owned treatment works, and organic waste
collected and sent for other disposal or waste treatment such as
incineration). Occupational exposures from inhalation of fugitive dust
and dermal exposure to dust from transfer and packaging operations and
from fugitive dust emissions from processing conditions of use are
possible if workers are unprotected. However, dermal exposure to
liquids is not anticipated. Similarly, inhalation exposure to fugitive
vapors is not expected due to PCTP's low vapor pressure (Ref. 4).
    Although releases of PCTP after the zinc PCTP is incorporated into
rubber are expected to be minimal, releases of additives from rubber
manufacturing are possible to water, air, and land (predominantly prior
to reaction process completion). Water releases are expected to be most
prevalent. Sources include process wastewater from cooling or heating
medium and vulcanization, where water has direct contact with the
rubber mixture. Releases to water can also occur from equipment and
general area cleaning. Releases are possible from the disposal of off-
spec product and empty transfer containers. Air releases are expected
to be minimal due to the low vapor pressure of PCTP. Occupational
inhalation and dermal exposure to dust is possible from unloading and
transfer operations when the PCTP mixture is added to process equipment
if workers are unprotected. Once incorporated into the rubber
formulation, the potential for worker exposure is not expected (Ref.
4).
    3. Hazard summary. The purpose of the Hazard Summary is to describe
the hazards of the five PBT chemicals. EPA did not perform a systematic
review of the literature to characterize the hazards of the five PBT
chemicals, and instead performed a limited survey of the reasonably
available scientific information. The information in this document does
not represent an exhaustive literature review nor is it an analysis of
relative importance or comparative dose-response among hazards. Due to
Congress' direction in TSCA to expeditiously regulate PBTs on the 2014
Work Plan and because risk evaluations were not required by Congress,
EPA prepared a fit-for-purpose summary of the hazards presented by the
five PBT chemicals. EPA leveraged previous data compilations and
existing information, wherever possible, as the initial data-gathering
approach and to survey the environmental and human health hazard data
and information. EPA did not evaluate the strengths and weaknesses of
individual studies, nor did EPA select studies to inform a point of
departure. The hazard data are reported from the literature with no
additional analysis or assessment. Reasonably available hazard
information is tabulated and briefly summarized within this document;
hazard values, unless noted otherwise (e.g., normalized to percent
active ingredient or purity), are as reported by authors, and were not
selected for use in conjunction with any particular

exposure pathway(s), risk assessment scenarios, or dose-response
analysis conducted by EPA. The Hazard Summary does take into
consideration public and peer review comments. Hazard information that
became available after the beginning of the peer review and public
comment process in June 2018 is not captured in the Hazard Summary. EPA
requests comments making the Agency aware of any more recent hazard
information available.
    Environmental and human health hazard data were compiled from
various primary and secondary sources of publicly available
information. The hazard summaries relevant to environmental hazard data
include toxicological information following acute and chronic exposures
for both aquatic and terrestrial wildlife. Due to a general lack of
data found for 2,4,6-TTBP and PCTP in the primary and secondary sources
initially searched, additional literature searches were conducted for
environmental hazard data for these chemicals. Generally, more aquatic
toxicity data following acute exposures are available for all five PBT
chemicals than are available for aquatic toxicity data following
chronic exposures. For four of the five PBT chemicals, excluding PCTP,
data were available for organisms spanning three trophic levels.
    The hazard summaries relevant to human health focus on repeated-
dose studies in laboratory mammals because these chemicals are expected
to persist and bioaccumulate in the environment and result in repeated
exposures to exposed human populations. In addition, in vitro studies
in cells and acute studies in mammals were included to characterize the
health concerns that were not examined in repeated-dose studies in
mammals. Available published and unpublished repeated-dose toxicity
data were tabulated according to health endpoints and the identified
studies are briefly summarized. Human health hazard data are presented
in the context of any available existing toxicological assessments. In
some cases, the identified studies did not observe any toxicological
effects. EPA did not conduct an analysis of relative importance of the
endpoints reported or do a comparative dose-response among hazards.
    The environmental and human health hazards of the five PBT
chemicals are summarized here. These hazard statements are not based on
a systematic review of the available literature and information may
exist that could refine the hazard characterization.
    DecaBDE: DecaBDE is toxic to aquatic invertebrates, fish, and
terrestrial invertebrates. Data indicate the potential for
developmental, neurological, and immunological effects, general
developmental toxicity and liver effects in mammals. There was some
evidence of genotoxicity. There was some evidence of carcinogenicity.
The studies presented in this document demonstrate these hazardous
endpoints.
    PIP (3:1): PIP (3:1) is toxic to aquatic plants, aquatic
invertebrates, sediment invertebrates and fish. Data indicate the
potential for reproductive and developmental effects, neurological
effects and effects on systemic organs, specifically adrenals, liver,
ovary, and heart in mammals. The studies presented in this document
demonstrate these hazardous endpoints.
    2,4,6-TTBP: 2,4,6-TTBP is toxic to aquatic plants, aquatic
invertebrates, and fish. Data indicate the potential for liver and
developmental effects. The studies presented in this document
demonstrate these hazardous endpoints.
    HCBD: HCBD is toxic to aquatic invertebrates, fish, and birds. Data
indicate the potential for renal, liver, and developmental effects in
mammals. HCBD has been identified as a possible human carcinogen. The
studies presented in this document demonstrate these hazardous
endpoints.
    PCTP: PCTP is toxic to protozoa, fish, terrestrial plants, and
birds. Data for analogous chemicals (pentachloronitrobenzene and
hexachlorobenzene) indicate the potential for liver effects in mammals
and systemic (body weight) effects for PCTP in mammals (no repeated-
dose animal or human epidemiological data were identified for PCTP).
The studies presented in this document demonstrate these hazardous
endpoints.

III. Regulatory Assessment of the PBT Chemicals

A. Regulatory Approach

    1. Developing options: Stakeholder engagement and consultations. In
addition to the consultations described in Unit VI, EPA sought comment
from experts on and users of the five PBT chemicals. The purpose of
these discussions was to create awareness and educate stakeholders on
the provisions under TSCA section 6(h); obtain input from
manufacturers, processors, distributors, users, academics, advisory
councils, and members of the public health community about past and
present uses of the PBT chemicals; identify practices related to the
use of the PBT chemicals; determine the importance of the PBT chemicals
in their various industries; compile knowledge about critical uses,
substitute chemicals or processes in various sectors; identify various
industry standards and performance specifications; identify health
effects; and craft potential risk reduction strategies. To this end,
EPA held a public meeting via webinar in September 2017, and attended a
``Fire Retardants in Plastics'' conference hosted by Applied Marketing
Information in April 2018. Where appropriate, EPA followed up on
pertinent details or issues raised in comments. EPA has met with, or
otherwise communicated with, more than 50 companies, including
manufacturers, processors, distributors, and chemical users as well as
trade associations and other non-government organizations to discuss
the topics outlined in this paragraph, and these discussions are cited
throughout this notice where they informed analysis.
    2. Potential exposures that EPA is not proposing to regulate. In
general, there are some activities or exposures that EPA is not
proposing to regulate, even though the Exposure and Use Assessment
(Ref. 4) identified exposures or potential exposures. One of these is
disposal. Under RCRA, there are comprehensive regulations governing the
disposal of hazardous and non-hazardous wastes. These range from
requirements for RCRA Subtitle C hazardous waste incinerators, which
must generally meet a destruction and removal efficiency of 99.99% or
more, to hazardous waste landfills, which include a double liner,
double leachate collection and removal systems, leak detection system,
run on, runoff, and wind dispersal controls, and a construction quality
assurance program, to municipal solid waste landfills, which must
implement certain requirements that are similar to some of the Subtitle
C requirements, to industrial nonhazardous and construction/demolition
waste landfills. Industrial nonhazardous and construction/demolition
waste landfills are primarily regulated under state regulatory
programs, but they must meet the criteria set forth in Federal
regulations for siting, groundwater monitoring and corrective action
and a prohibition on open dumping. Disposal by underground injection is
regulated under both RCRA and the Safe Drinking Water Act. In view of
this comprehensive, stringent program for addressing disposal, EPA is
proposing to determine that it is not practicable to impose additional
requirements under

TSCA on the disposal of these PBT chemicals.
    EPA is also not generally proposing to use its TSCA section 6(a)
authorities to regulate commercial use of products containing the PBT
chemicals. For example, EPA is not proposing to prohibit the continued
commercial use of articles or products that contain DecaBDE or PIP
(3:1), such as commercial aircraft. Such a prohibition would not be
practicable; to the contrary, it would be extremely burdensome,
necessitating the identification of products containing DecaBDE or PIP
(3:1), and the disposal of countless products, such as televisions and
computers, that would have to be replaced with new products. If the
continued commercial use of vehicles containing DecaBDE or PIP (3:1)
were prohibited, it would result in widespread economic impacts and
disruption in the channels of trade while the prohibited parts or
fluids were identified and replaced. EPA believes that, for most
products containing the PBT chemicals, it would be either extremely
burdensome, for vehicles, or unreasonable, because of the low
concentrations of PCTP in golf balls, for example, and, thus,
impracticable to prohibit or otherwise restrict the continued
commercial use of the products.
    Finally, EPA is not proposing to directly regulate occupational
exposure through mandated controls such as engineering controls or use
of personal protective equipment (PPE), such as gloves or respirators.
EPA expects there is compliance with federal and state laws, such as
worker protection standards, unless case-specific facts indicate
otherwise, and therefore existing OSHA regulations for worker