TSCA Section 5(a)(3) Determination for Premanufacture Notice (PMN) P-19-0189

Number: P-19-0189

TSCA Section 5(a)(3) Determination: The chemical substance is not likely to present an
unreasonable risk (5(a)(3)(C))

Chemical Name:

Generic: Fatty acids, polymers with alkanediol and 1,1 '-methylenebis[4-isocyanatobenzene]
Conditions of Use (intended, known, or reasonably foreseen)1:

Intended Conditions of Use (specific): Manufacture and process for use as a reactive polymer for
use in adhesives and sealants, consistent with 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
evaluated whether there are reasonably foreseen conditions of use and found none.

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.
EPA estimated that the new chemical substance could have limited persistence and a low
potential for bioaccumulation, such that repeated exposures are not expected to cause food-chain
effects via accumulation in exposed organisms. Additionally, although EPA estimated that the
hydrolysis product could be very persistent, the substance has a 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's

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.

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TSCA Section 5(a)(3) Determination for Premanufacture Notice (PMN) P-19-0189

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TSCA New Chemicals Program Chemical Category for Diisocyanates , the physical/chemical
properties of the new chemical substance and test data on analogous chemical substances, EPA
estimates that the chemical substance has low environmental hazard and potential for the
following human health hazards: skin sensitization, respiratory sensitization, specific target
organ toxicity. EPA concludes that the new chemical substance is not likely to present an
unreasonable risk under the conditions of use.

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 for
analogues (polymers with isocyanates) and of the hydrolysis product using data for analogues
(polymers) and data submitted for the new chemical substance. In wastewater treatment, the new
chemical substance is expected to be removed with an efficiency of 90% to 99% due to rapid
hydrolysis and the hydrolysis product is expected to be removed with an efficiency of 90% due
to sorption. Removal of the hydrolysis product by biodegradation is negligible. Sorption of the
hydrolysis product to sludge is expected to be strong and to soil and sediment is expected to be
very strong. Migration of the new chemical substance to groundwater is expected to be
negligible due to rapid hydrolysis and migration of the hydrolysis product to groundwater is
expected to be negligible due to very strong sorption to soil and sediment. Due to low estimated
vapor pressure and Henry's law constant, the new chemical substance and the hydrolysis product
are expected to undergo negligible volatilization to air. Overall, these estimates indicate that the
new chemical substance and the hydrolysis product have low potential to volatilize to air and low
potential to migrate to groundwater.

•j

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 for analogues
(polymers with isocyanates) and of the hydrolysis product using data for analogues (polymers)
and data submitted for the new chemical substance. EPA estimated that the new chemical
substance's hydrolysis half-life is minutes to hours; and that the hydrolysis product's aerobic and
anaerobic biodegradation half-lives are > 6 months. These estimates indicate that the new
chemical substance may have limited persistence in aerobic environments (e.g., surface water)
and anaerobic biodegradation environments (e.g., sediment) due to hydrolysis. Further, these

2	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.

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 there are equivalent or analogous data. (64 FR 60194;
November 4, 1999)

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TSCA Section 5(a)(3) Determination for Premanufacture Notice (PMN) P-19-0189

estimates indicate that the hydrolysis product may be very persistent in aerobic environments
(e.g., surface water) and anaerobic environments (e.g., sediment).

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 data for
analogues (polymers with isocyanates) and of the hydrolysis product to bioaccumulate using data
for analogues (polymers). EPA estimated that the new chemical substance has low
bioaccumulation potential based on rapid hydrolysis and the hydrolysis product has low
bioaccumulation potential based on large predicted molecular volume, which limits
bioavailability. EPA estimated that the new chemical substance could have limited persistence
and a low potential for bioaccumulation, such that repeated exposures are not expected to
cause food-chain effects via accumulation in exposed organisms. Although EPA estimated that
the hydrolysis product could be very persistent, the substance has a low potential for
bioaccumulation, such that repeated exposures are not expected to cause food-chain effects via
accumulation in exposed organisms.

Human Health Hazard5: Human health hazard is relevant to whether a new chemical substance
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, data on the new chemical substance, by comparing it to
structurally analogous chemical substances for which there is information on human health
hazard, and other structural information. Absorption of the new chemical substance is expected

4	Bioaccumulation: A chemical substance is considered to have a low potential for bioaccumulation if there are
bioconcentration factors (BCF) or bioaccumulation factors (BAF) of less than 1,000 or 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 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 there are equivalent or analogous data.
(64 FR 60194; November 4 1999)

5	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
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 httos ://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.

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TSCA Section 5(a)(3) Determination for Premanufacture Notice (PMN) P-19-0189

to be nil by all routes and good by all routes for the methylene diphenyl diisocyanate (MDI)
monomer based on physical/chemical properties. For the new chemical substance, EPA
identified hazards for skin and respiratory sensitization based on data for the new chemical
substance and the residual MDI and respiratory tract effects based on the residual. The submitter
provided data on the new chemical substance that indicated it was non-irritating to skin and eyes
(OECD 438 and 439), positive for skin sensitization (OECD 429), not mutagenic in an Ames
assay with and without metabolic activation (OECD 471), and not acutely toxic to rats when
gavaged up to 2000 mg/kg-bw (OECD 423). EPA qualitatively assessed hazards for skin and
respiratory sensitization.

Environmental Hazard6: 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 estimated environmental hazard of this new chemical substance using
predictions based on the negligible water solubility of the new chemical substance. Acute and
chronic toxicity values estimated for fish, aquatic invertebrates, and algae are all no effects at
saturation. These toxicity values indicate that the new chemical substance is expected to have
low environmental hazard. Because hazards are not expected up to the water solubility limit,
acute and chronic concentrations of concern are not identified.

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

6 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 thsan 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-futures-p2-
framework-manual).

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TSCA Section 5(a)(3) Determination for Premanufacture Notice (PMN) P-19-0189

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 assessment, EPA assessed worker exposure via dermal contact; inhalation exposure to
workers is not expected. Releases to air and landfill were estimated. Exposure to the general
population was not assessed because releases to water are not expected and all predicted releases
to landfill or 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 assesses risks to workers 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 workers were not evaluated via inhalation because exposures are expected to be
negligible. Sensitization hazards to workers via dermal contact were identified based on data for
the new chemical substance and residual MDI. 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 and eye
protection. EPA expects that employers will require and that workers will use appropriate PPE
consistent with the Safety Data Sheet (SDS) prepared by the submitter, in a manner adequate to
protect them.

Risks to the general population were not evaluated because general population exposures are not
expected. Risks to consumers were not evaluated because consumer uses were not identified as
conditions of use.

Risks from acute and chronic exposures to the environment are not expected at any concentration
of the new chemical substance soluble in water (i.e., no effects at saturation).

Because worker exposures can be controlled by PPE, general population exposures are not
expected, no unreasonable risks to the environment were identified, and there are no expected
consumer exposures, EPA has determined that the new chemical substance is not likely to
present unreasonable risk to human health or the environment under the conditions of use.

04/09/2020	/s/

Date:	Tala R. Henry, Ph.D.

Deputy Director for Programs

Office of Pollution Prevention and Toxics

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