Background on Risk Evaluation Under the Toxic Substances Control Act (TSCA): C.I. Pigment Violet 29

Background on Risk Evaluation Under the Toxic Substances Control Act (TSCA): C.I. Pigment Violet 29

INSIGHTi

Background on Risk Evaluation Under the
Toxic Substances Control Act (TSCA): C.I.
Pigment Violet 29
September 12, 2022
In 2016, the Frank R. Lautenberg Chemical Safety for the 21st Century Act (LCSA; P.L. 114-182)
amended Title I of the Toxic Substances Control Act (TSCA; 15 U.S.C. §2601 et seq.) to direct the U.S.
Environmental Protection Agency (EPA) to systematically prioritize chemicals for risk evaluation. (For
more information, see CRS Report R45149, Title I of the Toxic Substances Control Act (TSCA): A
Summary of the Statute.) The purpose of the risk evaluations is to determine whether particular chemicals
warrant regulation in terms of the risks associated with their manufacture, processing, distribution, use, or
disposal. If EPA identifies “unreasonable” risk to human health or the environment associated with one or
more of the elements of a chemical’s lifecycle, TSCA Section 6 directs EPA to promulgate a rule to
mitigate those risks. TSCA Section 9 limits EPA’s authority to regulate a chemical under TSCA if another
law may be used to regulate a chemical for the unreasonable risk identified by the agency.
As amended, TSCA Section 6 directed EPA to select 10 chemicals for risk evaluation from a list of 90
chemicals that the agency identified in 2014 as warranting risk assessment. EPA based this list on a
screening of 345 chemicals for potential hazard and exposure, and persistence and bioaccumulation
characteristics. With more than 86,000 chemicals on the TSCA Inventory, EPA’s screening approach was
intended to focus the agency’s resources and attention on a select group of chemicals for which sufficient
scientific and technical information is available to suggest greater concern to human health or the
environment. Pursuant to TSCA Section 6, EPA selected the initial 10 chemicals for risk evaluation,
including C.I. Pigment Violet 29, in 2016 (81 Federal Register 91927-91929, December 19, 2016).
Each chemical substance that EPA evaluates has unique properties, uses, and risks, which may warrant
different risk management approaches. The process of conducting risk evaluations and assessing risk
management options involves judgments about the reliability of available scientific and technical
information. Aspects of this process and what information EPA identifies as the basis for justifying certain
regulatory action can generate disagreement between the agency and stakeholders (e.g., industry,
environmental and public health organizations). As EPA continues to implement TSCA, the agency’s risk
evaluations and related actions are likely to receive scrutiny among stakeholders. Congress may consider
assessing EPA’s implementation of TSCA, as amended by the LCSA, and the resulting outcomes from the
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agency’s actions and decisions. The next section discusses EPA’s risk evaluation for C.I. Pigment Violet
29 and potential next steps toward addressing the unreasonable risks that the agency identified.
C.I. Pigment Violet 29
In 2016, EPA selected C.I. Pigment Violet 29 (Anthra[2,1,9-def:6,5,10-d’e’f’]diisoquinoline-
1,3,8,10(2H,9H)-tetrone; CAS Number 81-33-4) as one of the initial 10 chemicals for which a risk
evaluation would be conducted. C.I. Pigment Violet 29 is predominantly used as an intermediate chemical
to produce other related pigments but may also be used in the manufacture of various paints and coatings
and incorporated into plastic and rubber products. According to EPA, approximately 600,000 pounds of
C.I. Pigment Violet 29 are manufactured in, or imported to, the United States annually.
In January 2021, EPA finalized its risk evaluation for C.I. Pigment Violet 29, identifying unreasonable
risks to the health of workers and occupational non-users from 10 of 14 conditions of use that were
evaluated. EPA did not identify unreasonable risks for consumers, bystanders, the general population, or
the environment for any of the evaluated conditions of use. EPA based its risk determinations on a
comparison of various sources of scientific information. The agency considered the predicted exposure to
C.I. Pigment Violet 29 from various exposure scenarios (e.g., workers involved in handling the chemical
with or without the use of a respirator) and an estimated level of exposure expected not to result in the
development of adverse health effects while taking into account a margin of exposure. EPA’s risk
determinations regarding potential environmental effects are based on the predicted exposure to C.I.
Pigment Violet 29 for various species compared to the estimated level of exposure expected not to result
in the development of adverse effects in species at the population level.
With regard to unreasonable risks to the health of workers and occupational non-users, EPA determined
that certain respiratory effects are associated with chronic exposure through inhalation based on rodent
studies conducted for a comparable chemical, Carbon Black (CAS Number 1333-86-4). In June 2021,
EPA announced its intention to approach the TSCA unreasonable risk determinations by making one
determination for a chemical substance rather than multiple determinations for each condition of use. In
September 2022, EPA finalized a revised risk determination for C.I. Pigment Violet 29, which indicates
that the chemical presents unreasonable risks to human health. This revised risk determination would
supersede the January 2021 risk determinations in the risk evaluation.
Given that EPA identified unreasonable risks associated with C.I. Pigment Violet 29, the agency is
developing a rule under TSCA Section 6 to address such risks. Section 6(a) identifies seven risk
management options that EPA may use alone or in combination to address the risks of C.I. Pigment Violet
29, including prohibiting the manufacture of the chemical and requiring manufacturers of the chemical to
communicate the chemical’s risks to allow downstream processors, users, and distributors the opportunity
to take applicable protective measures. In developing the rule, EPA is required pursuant to Section 6 to
identify various risk management options that would adequately address the identified unreasonable risk
and determine the associated costs for each proposed risk management option. Once EPA proposes a risk
management rule for C.I. Pigment Violet 29, Congress may conduct oversight or consider legislation with
regard to EPA’s efforts to manage risks associated with C.I. Pigment Violet 29 and whether such efforts
are aligned with the intent of the TSCA amendments.

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Author Information

Jerry H. Yen

Analyst in Environmental Policy

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