TSCA Section 5(a)(3) Determination for Premanufacture Notice (PMN) P-17-0294
Number: P-17-0294
TSCA Section 5(a)(3) Determination: The chemical substance is not likely to present an
unreasonable risk (5(a)(3)(C))
Chemical Name:
Specific: 2-Butanone, 3-methyl-, peroxide; CASRN: 182893-11-4
Conditions of Use (intended, known, or reasonably foreseen)1:
Intended conditions of use (specific): Import for use use as an organic peroxide polymerization
initiator for unsaturated acrylic, unsaturated polyester, and vinyl ester resins used in
traditional acrylic systems such as acrylic solid surface, acrylic adhesives, acrylic
castings and acrylic coatings, consistent with the manufacturing, processing, use,
distribution, and disposal information described in the PMN.
Known conditions of use: Applying such factors as described in footnote 1, EPA evaluated
whether there are known conditions of use and found none.
Reasonably foreseen conditions of use: Applying such factors as described in footnote 1, EPA
has identified the use of the new chemical substance as a curing agent for thermoset
resins as reasonably foreseen based on a patent search.
Summary: The chemical substance is not likely to present an unreasonable risk of injury to
health or the environment, without consideration of costs or other nonrisk factors, including an
unreasonable risk to a potentially exposed or susceptible subpopulation identified as relevant by
the Administrator under the conditions of use, based on the risk assessment presented below and
the terms of the proposed Significant New Use Rule (SNUR) signed by EPA.2 EPA estimated
1	Under TSCA § 3(4), the term "conditions of use" means "the circumstances, as determined by the Administrator,
under which a chemical substance is intended, known, or reasonably foreseen to be manufactured, processed,
distributed in commerce, used, or disposed of." In general, EPA considers the intended conditions of use of a new
chemical substance to be those identified in the section 5(a) notification. Known conditions of use include activities
within the United States that result from manufacture that is exempt from PMN submission requirements.
Reasonably foreseen conditions of use are future circumstances, distinct from known or intended conditions of use,
under which the Administrator expects the chemical substance to be manufactured, processed, distributed, used, or
disposed of. The identification of "reasonably foreseen" conditions of use will necessarily be a case-by-case
determination and will be highly fact-specific. Reasonably foreseen conditions of use will not be based on
hypotheticals or conjecture. EPA's identification of conditions of use includes the expectation of compliance with
federal and state laws, such as worker protection standards or disposal restrictions, unless case-specific facts indicate
otherwise. Accordingly, EPA will apply its professional judgment, experience, and discretion when considering such
factors as evidence of current use of the new chemical substance outside the United States, evidence that the PMN
substance is sufficiently likely to be used for the same purposes as existing chemical substances that are structurally
analogous to the new chemical substance, and conditions of use identified in an initial PMN submission that the
submitter omits in a revised PMN. The sources EPA uses to identify reasonably foreseen conditions of use include
searches of internal confidential EPA PMN databases (containing use information on analogue chemicals), other
U.S. government public sources, the National Library of Medicine's Hazardous Substances Data Bank (HSDB), the
Chemical Abstract Service STN Platform, REACH Dossiers, technical encyclopedias (e.g., Kirk-Othmer and
Ullmann), and Internet searches.
2	Reasonably foreseen conditions of use subject to a proposed SNUR are not likely to present an unreasonable risk
of injury to health or the environment. Based on EPA's experience, it is the Agency's judgment that a new use
would not commence during the pendency of a proposed SNUR because web posting of a proposed SNUR serves as
the cut-off date for a significant new use. Therefore, manufacturers and processors would not commence a
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TSCA Section 5(a)(3) Determination for Premanufacture Notice (PMN) P-17-0294
that the new chemical substance has limited persistence and low potential for bioaccumulation,
such that repeated exposures are not expected to cause food-chain effects via accumulation in
exposed organisms. Based on test data on the new chemical substance, EPA estimates that the
chemical substance has high environmental hazard and potential for the following human health
hazards: skin corrosion, serious eye damage, skin sensitization, respiratory sensization, and specific
target organ toxicity. The PMN describes conditions of use that mitigate the human health and
environmental risks. Therefore, EPA concludes that the new chemical is not likely to present
unreasonable risk to human health or the environment under the intended conditions of use.
As set forth below, the information available to EPA is sufficient to permit the Agency to
conduct a reasoned evaluation of the health and environmental effects of the chemical substance
under the conditions of use that are not subject to the proposed SNUR, in order to determine that
the chemical substance is not likely to present an unreasonable risk under those conditions of
use. As such, EPA does not need to impose testing requirements to conduct this evaluation.
Whether testing is needed to evaluate the effects of the intended, known, or reasonably foreseen
conditions of use of a chemical substance subject to a PMN is determined on a case-by-case
basis. To the extent that testing may be necessary to conduct a reasoned evaluation of the health
or environmental effects of the reasonably foreseen conditions of use that are subject to the
proposed SNUR, EPA will make the appropriate determination if a Significant New Use Notice
(SNUN) is submitted following finalization of the SNUR.
EPA found no known conditions of use, assessed the intended conditions of use, and addressed
reasonably foreseen conditions of use by proposing a SNUR. Therefore, EPA determines the
new chemical substance is not likely to present unreasonable risk to human health or the
environment.
Fate: Environmental fate is the determination of which environmental compartment(s) a
chemical moves to, the expected residence time in the environmental compartment(s) and
removal and degradation processes. Environmental fate is an important factor in determining
exposure and thus in determining whether a chemical may present an unreasonable risk. EPA
estimated physical/chemical and fate properties of the new chemical substance using data
submitted for the new chemical substance and EPI (Estimation Program Interface) Suite™
(http://www.epa.gov/tsca-screening-tools/epi-suitetm-estimation-programinterface). In
wastewater treatment, the new chemical substance is expected to be removed with an efficiency
of 90% to 99% due to reactivity with activated sludge organic matter. Removal of the new
chemical substance by biodegradation is negligible. Sorption of the new chemical substance to
prohibited new use that would be legally required to cease upon the finalization of the SNUR. Once a SNUR is final
and effective, no manufacturer or processor - including the PMN submitter - may undertake the conditions of use
identified as a significant new use of the PMN substance in the SNUR. EPA must first evaluate the new use in
accordance with the requirements of TSCA Section 5 and (a) either conclude that the new use is not likely to present
an unreasonable risk under the conditions of use; or (b) take appropriate action under section 5(e) or 5(f). If EPA
were not to finalize the proposed SNUR, then that decision would be based on information and data provided to the
Agency during the comment period demonstrating that the reasonably foreseen conditions of use subject to the
proposed SNUR are not likely to present an unreasonable risk. Under either scenario, the reasonably foreseen
condition of use is not likely present an unreasonable risk.
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TSCA Section 5(a)(3) Determination for Premanufacture Notice (PMN) P-17-0294
sludge, soil, and sediment is expected to be low. Migration of the new chemical substance to
groundwater is expected to be negligible due to reactivity with soil organic matter.
Due to the low estimated Henry's law constant, the new chemical substance is expected to
undergo negligiblevolatilization to air. Overall, these estimates indicate that the new chemical
substance has low potential to volatilize to air or migrate to groundwater.
-2
Persistence : Persistence is relevant to whether a new chemical substance is likely to present an
unreasonable risk because chemicals that are not degraded in the environment at rates that
prevent substantial buildup in the environment, and thus increase potential for exposure, may
present a risk if the substance presents a hazard to human health or the environment. EPA
estimated degradation half-lives of the new chemical substance using data submitted for the new
chemical substance and EPI Suite™. EPA estimated that the new chemical substance's aerobic
biodegradation half-life is unknown, anaerobic biodegradation half-life is > 6 months, and
hydrolysis half-life is > months. This substance is expected to react with organic matter in
environmental media. Thus, it will have limited persistence in the environment.
Bioaccumulation4: Bioaccumulation is relevant to whether a new chemical substance is likely
to present an unreasonable risk because substances that bioaccumulate in aquatic and/or
terrestrial species pose the potential for elevated exposures to humans and other organisms via
food chains. EPA estimated the potential for the new chemical substance to bioaccumulate using
EPI Suite™. EPA estimated that the new chemical substance has low bioaccumulation potential
based on BCFBAF model result < 1000 (bioconcentration factor = 3 [estimated by linear
regression from log Kow] and bioaccumulation factor = 1 [estimated by the Arnot-Gobas method
(2003)]).5 EPA estimated that the new chemical substance could have limited persistence and
low potential for bioaccumulation, such that repeated exposures are not expected to cause
food-chain effects via accumulation in exposed organisms.
Human Health Hazard6: Human health hazard is relevant to whether a new chemical substance
3	Persistence: A chemical substance is considered to have limited persistence if it has a half-life in water, soil or
sediment of less than 2 months or if there are equivalent or analogous data. A chemical substance is considered to be
persistent if it has a half-life in water, soil or sediments of greater than 2 months but less than or equal to 6 months
or if there are equivalent or analogous data. A chemical substance is considered to be very persistent if it has a half-
life in water, soil or sediments of greater than 6 months or if there are equivalent or analogous data. (64 FR 60194;
November 4, 1999)
4	Bioaccumulation: A chemical substance is considered to have a low potential for bioaccumulation if there are
bioconcentration factors (BCF) or bioaccumulation factors (B AF) of less than 1,000 or if there are equivalent or
analogous data. A chemical substance is considered to be bioaccumulative if there are BCFs or BAFs of 1,000 or
greater and less than or equal to 5,000 or if there are equivalent or analogous data. A chemical substance is
considered to be very bioaccumulative if there are BCFs or BAFs of 5,000 or greater or if there are equivalent or
analogous data. (64 FR 60194; November 4 1999)
5	Arnot JA, Gobas FAPC. 2003. A generic QSAR for assessing the bioaccumulation potential of organic chemicals
in aquatic food webs. QSAR and Combinatorial Science 22: 337-345.
6	A chemical substance is considered to have low human health hazard if effects are observed in animal studies with
a No Observed Adverse Effect Level (NOAEL) equal to or greater than 1,000 mg/kg/day or if there are equivalent
data on analogous chemical substances; a chemical substance is considered to have moderate human health hazard if
effects are observed in animal studies with a NOAEL less than 1,000 mg/kg/day or if there are equivalent data on
analogous chemical substances; a chemical substance is considered to have high human health hazard if there is
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TSCA Section 5(a)(3) Determination for Premanufacture Notice (PMN) P-17-0294
is likely to present an unreasonable risk because the significance of the risk is dependent upon
both the hazard (or toxicity) of the chemical substance and the extent of exposure to the
substance. EPA estimated the human health hazard of this chemical substance based on its
estimated physical/chemical properties and available data on the new chemical substance.
Absorption of the new chemical substance is expected to be good via all routes based on
physical/chemical properties and submitted studies. For the new chemical substance, EPA
identified corrosion to all tissues, skin and respiratory sensitization, and liver effects as hazards
based on data on the new chemical substance. Submitted tests of the new chemical substance
reported the test substance as corrosive (OECD 404), sensitizing in a guinea pig maximization
test (OECD 406), negative for mutagenicity (OECD 476, 471), having low acute dermal toxicity
(OECD 402), and causing liver effects in a 28 day oral study (OECD 407). EPA identified a
NOAEL of 15 mg/kg/day based on liver effects, which was used to derive exposure route- and
population-specific points of departure for quantitative risk assessment. EPA qualitatively
evaluated skin and respiratory sensitization and corrosion effects.
n
Environmental Hazard : Environmental hazard is relevant to whether a new chemical
substance is likely to present unreasonable risk because the significance of the risk is dependent
upon both the hazard (or toxicity) of the chemical substance and the extent of exposure to the
substance. EPA determined the environmental hazard for this new chemical substance based on
acute and chronic toxicity data submitted for the new chemical substance. This substance falls
o
within the EPA's TSCA New Chemicals Program Chemical Category for Peroxides. Acute
toxicity values measured for fish, aquatic invertebrates, and algae are 16 mg/L, 34 mg/L, and
0.98 mg/L, respectively. Chronic toxicity values measured for fish, aquatic invertebrates, and
algae are 8.5 mg/L, 18 mg/L, and 0.316 mg/L, respectively. These toxicity values indicate that
the new chemical substance is expected to have high environmental hazard. Application of
evidence of adverse effects in humans or conclusive evidence of severe effects in animal studies with a NOAEL of
less than or equal to 10 mg/kg/day or if there are equivalent data on analogous chemical substances. EPA may also
use Benchmark Dose Levels (BMDL) derived from benchmark dose (BMD) modeling as points of departure for
toxic effects. See https://www.epa.gov/bmds/what-benchmark-dose-software-bmds. Using this approach, a BMDL
is associated with a benchmark response, for example a 5 or 10 % incidence of effect. The aforementioned
characterizations of hazard (low, medium, high) would also apply to BMDLs. In the absence of animal data on a
chemical or analogous chemical substance, EPA may use other data or information such as from in vitro assays,
chemical categories (e.g., Organization for Economic Co-operation and Development, 2014 Guidance on Grouping
of Chemicals, Second Edition. ENV/JM/MONO(2014)4. Series on Testing & Assessment No. 194. Environment
Directorate, Organization for Economic Co-operation and Development, Paris, France.
(http://www.oecd.org/officialdocuments/publicdisplavdocumentpdf/?cote=env/im/mono(2014)4&doclanguage=en)).
structure-activity relationships, and/or structural alerts to support characterizing human health hazards.
7	A chemical substance is considered to have low ecotoxicity hazard if the Fish, Daphnid and Algae LC50 values are
greater than 100 mg/L, or if the Fish and Daphnid chronic values (ChVs) are greater than 10.0 mg/L, or there are not
effects at saturation (occurs when water solubility of a chemical substance is lower than an effect concentration), or
the log Kow value exceeds QSAR cut-offs. A chemical substance is considered to have moderate ecotoxicity hazard
if the lowest of the Fish, Daphnid or Algae LC50s is greater than 1 mg/L and less than 100 mg/L, or where the Fish
or Daphnid ChVs are greater than 0.1 mg/L and less than 10.0 mg/L. A chemical substance is considered to have
high ecotoxicity hazard, or if either the Fish, Daphnid or Algae LC50s are less than 1 mg/L, or any Fish or Daphnid
ChVs is less than 0.1 mg/L (Sustainable Futures https://www.epa.gov/sustainable-futures/sustainable-fiitures-p2-
framework-manual).
8	TSCA New Chemicals Program (NCP) Chemical Categories, https://www.epa.gov/reviewing-new-chemicals-
under-toxic-substances-control-act-tsca/chemical-categories-used-review-new.
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TSCA Section 5(a)(3) Determination for Premanufacture Notice (PMN) P-17-0294
assessment factors of 4 and 10 to acute and chronic toxicity values, respectively, results in acute
and chronic concentrations of concern of 0.245 mg/L (245 ppb) and 0.032 mg/L
(32 ppb), respectively.
Exposure: The exposure to a new chemical substance is potentially relevant to whether a new
chemical substance is likely to present unreasonable risks because the significance of the risk is
dependent upon both the hazard (or toxicity) of the chemical substance and the extent of
exposure to the substance.
EPA estimates occupational exposure and environmental release of the new chemical substance
under the intended conditions of use described in the PMN using ChemSTEER (Chemical
Screening Tool for Exposures and Environmental Releases; https://www.epa.gov/tsca-screening-
tools/chemsteer-chemical-screening-tool-exposures-and-environmental-releases). EPA uses
EFAST (the Exposure and Fate Assessment Screening Tool; https://www.epa.gov/tsca-
screening-tools/e-fast-exposure-and-fate-assessment-screening-tool-version-2014) to estimate
general population, consumer, and environmental exposures.
EPA considers workers to be a potentially exposed or susceptible subpopulation (PESS) on the
basis of greater exposure potential compared to the general population. EPA also considers PESS
in conducting general population drinking water exposures by evaluating risks associated with
water intake rates for multiple age groups, ranging from infants to adults. EPA considers
consumers of specific products to be a potentially exposed or susceptible subpopulation on the
basis of greater exposure potential compared to the general population who do not use specific
products.
For this new chemical assessment, EPA assessed worker exposure via dermal and inhalation
exposure. Releases to water, air, and landfill were estimated. Exposure to the general population
was assessed via drinking water and fish ingestion. Exposures to the general population via
groundwater impacted by landfill leaching and via inhalation were not assessed because
exposures from releases to landfill and air are expected to be negligible (below modeling
thresholds). Consumer exposures were not assessed because consumer uses were not identified
as conditions of use.
Risk Characterization: EPA applies a margin of exposure approach to calculate potential
human health risks of new chemicals. A benchmark (acceptable) margin of exposure (MOE) is
derived by applying uncertainty factors for the following types of extrapolations: intra-species
extrapolation (UFH = 10 to account for variation in sensitivity among the human population),
inter-species extrapolation (UFa = 10 to account for extrapolating from experimental animals to
humans) and LOAEL-to-NOAEL extrapolation (UFL = 10 to account for using a LOAEL when a
NOAEL is not available). Hence, in the New Chemicals Program, a benchmark MOE is typically
100 and 1,000 when NOAELs and LOAELs, respectively, are used to identify hazard. When
allometric scaling or pharmacokinetic modeling is used to derive an effect level, the UFh may be
reduced to 3, for a benchmark MOE of 30. The benchmark MOE is used to compare to the MOE
calculated by comparing the toxicity NOAEL or LOAEL to the estimated exposure
concentrations. When the calculated MOE is equal to or exceeds the benchmark MOE, the new
chemical substance is not likely to present an unreasonable risk. EPA assesses risks to workers
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TSCA Section 5(a)(3) Determination for Premanufacture Notice (PMN) P-17-0294
considering engineering controls described in the PMN but in the absence of personal protective
equipment (PPE) such as gloves and respirators. If risks are preliminarily identified, EPA then
considers whether the risks would be mitigated by the use of PPE (e.g., impervious gloves,
respirator).
Risks to human health for the new chemical substance were evaluated using the route-specific
effect levels (i.e., NOAEL) described above. Risks were identified for workers for liver effects
via dermal exposure based on quantitative hazard data for the new chemical substance (MOE =
3; Benchmark MOE = 100). Risks were not identified for workers for liver effects via inhalation
based on quantitative hazard data for the new chemical substance (MOE = 1,527; Benchmark
MOE = 100). Skin and respiratory sensitization hazards and corrosion hazards to workers via
dermal and inhalation exposures were identified based on submitted test data on the new
chemical substance. Risks for these endpoints were not quantified due to a lack of dose-response
for these hazards. However, exposures can be mitigated by the use of appropriate personal
protective equipment (PPE), including impervious gloves, eye protection, and respiratory
protection (Assigned Protection Factor of 50). EPA expects that employers will require and that
workers will use appropriate PPE consistent with the Safety Data Sheet prepared by the new
chemical submitter, in a manner adequate to protect them.
Risks were not identified for the general population for liver effects via drinking water or fish
ingestion based on quantitative hazard data for the new chemical substance (MOEAduitDw =
22,523; MOEinfantDW = 5,363; MOEHsh ingestion = 416,667; Benchmark MOE = 100). Skin
sensitization and corrosion hazards to the general population are not expected via drinking water
or fish ingestion due to dilution of the chemical substance in the media. Risks were not evaluated
for the general population via groundwater impacted by landfill leaching and inhalation, because
exposures via these media were expected to be negligible. Risks to consumers were not
evaluated because consumer uses were not identified as conditions of use.
Risks to the environment were evaluated by comparing estimated surface water concentrations
with the acute and chronic concentrations of concern. Risks to the environment were not
identified due to releases to water that did not exceed the acute COC or the chronic COC.
It is reasonably foreseen, based on a patent search on the new chemical substance, that the new
chemical substance could be used for other uses which may result in greater worker exposures or
environmental releases. The SNUR that has been proposed for this chemical substance defines
certain conditions of use as significant new uses. The proposed significant new uses include use
other than as an organic peroxide polymerization initiator for unsaturated acrylic, unsaturated
polyester and vinyl ester resins. Conditions of use that fall under the restrictions of the proposed
SNUR are not likely to present unreasonable risk of injury to health or the environment because
(1) those conditions of use are not likely to be commenced during the pendency of the proposed
SNUR, and (2) upon finalization of the SNUR, those conditions of use would be prohibited
unless and until EPA makes an affirmative determination that the significant new use is not
likely to present an unreasonable risk or takes appropriate action under section 5(e) or 5(f).
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TSCA Section 5(a)(3) Determination for Premanufacture Notice (PMN) P-17-0294
4/29/2020			/s/
Date:	Tala R. Henry, Ph.D.
Deputy Director for Programs
Office of Pollution Prevention and Toxics
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