TSCA Section 5(a)(3) Determination for Premanufacture Notice (PMN) P-19-0170

Number: P-19-0170

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

Chemical Name:

Generic: Heteroatom-substituted alkyl triethoxysilane, reaction products with methylated
formaldehyde-melamine polymer

Conditions of Use (intended, known, or reasonably foreseen)1:

Intended conditions of use (specific): Manufacture for use as a coupling agent in elastomer-based
formulations that will be used in molding operations to manufacture different types of
rubber articles including but not limited to rubber tires, 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
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.
Although EPA estimated that the new chemical substance may have limited persistence, the
hydrolysis product of the new chemical substance could be very persistent. The new chemical
substance and its hydrolysis product have low potential for bioaccumulation, such that repeated
exposures are not expected to cause food-chain effects via accumulation in exposed organisms.

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-19-0170

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Based on EPA's TSCA New Chemicals Program Chemical Categories for Alkoxysilanes and
test data on analogous chemical substances, EPA estimates that the chemical substance has
moderate environmental hazard and potential for the following human health hazards: irritation,
lung effects, systemic effects, and carcinogenicity. 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 triethoxysilyl groups) and of the hydrolysis product using EPI
(Estimation Program Interface) Suite™ (http://www.epa.gov/tsca-screening-tools/epi-suitetm-
estimation-program-interface). 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 0% to 25% due to low biodegradability,
low sorption, and low stripping. Removal of the hydrolysis product by biodegradation is
negligible. Sorption of the hydrolysis product to sludge is expected to be low and to soil and
sediment is expected to be low to moderate. 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 moderate to rapid due to low to moderate 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 has low potential to
volatilize to air or migrate to groundwater; and that the hydrolysis product has low potential to
volatilize to air and has moderate to high 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 triethoxysilyl groups) and of the hydrolysis product using EPI Suite™. EPA
estimated 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 environments (e.g., sediments) due to
hydrolysis. Further, these estimates indicate that the hydrolysis product may be very persistent in
aerobic environments (e.g., surface water) and anaerobic environments (e.g., sediment).

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 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-19-0170

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 triethoxysilyl groups) and of the hydrolysis product to
bioaccumulate using EPI Suite™. 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 BCFBAF model result < 1000 (hydrolysis product
bioconcentration factor = 3 [estimated] and bioaccumulation factor = 1 [estimated]). 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, by comparing it to structurally analogous chemical
substances for which there is information on human health hazard, and other structural
information. Absorption of the high molecular weight species (MW > 1000 Da) is expected to be
nil all routes, based on physical/chemical properties; absorption of the low molecular weight
fractions ([claimed CBI]% < 500 and [claimed CBI]% < 1000 Da) is expected to be moderate

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 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.

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TSCA Section 5(a)(3) Determination for Premanufacture Notice (PMN) P-19-0170

through the skin, moderate through the GI tract, and poor through the lungs, based on
physical/chemical properties. For the new chemical substance, EPA identified irritation to all
exposed tissues (e.g., eyes, skin, respiratory tract) as a hazard based on reactivity. EPA identified
potential lung effects as a hazard based on a structural alert for alkoxysilane, and systemic effects
and carcinogenicity as hazards based on release of formaldehyde via oral exposures only. EPA
identified PODs for lung effects (NOAEL of 75 mg/kg-day for inhalation exposures), systemic
effects (NOAEL of 15 mg/kg-day for a potential metabolite from oral exposures), and cancer
(oral slope factor of 2.1 x 10"2 per mg/kg/day for a potential metabolite from oral exposures);
however, exposure via inhalation and oral routes are not expected so risks were not quantified
via these routes. EPA evaluated skin and eye irritation qualitatively.

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 the
Ecological Structure Activity Relationships (ECOSAR) Predictive Model
(https://www.epa.gov/tsca-screening-tools/ecological-structure-activitv-relationships-ecosar-
predictive-model); specifically the QSAR for aromatic triazines. Acute toxicity values for the
new chemical substance estimated for fish, aquatic invertebrates, and algae are >100 mg/L, >
100 mg/L, and 2.79 mg/L, respectively. Chronic toxicity values for the new chemical substance
estimated for fish, aquatic invertebrates, and algae are > 10 mg/L, > 10 mg/L, and 0.698 mg/L
(ACR of 4), respectively. These toxicity values indicate that the new chemical substance is
expected to have moderate environmental hazard. Application of assessment factors of 4 and 10
to acute and chronic toxicity values, respectively, results in acute and chronic concentrations of
concern of 0.698 mg/L (698 ppb) and 0.07 mg/L (70 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-

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 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-futures-p2-
framework-manual).

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TSCA Section 5(a)(3) Determination for Premanufacture Notice (PMN) P-19-0170

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 exposure and
inhalation exposure to workers is not expected. Releases to air were estimated. Exposure to the
general population was not assessed because releases to air were 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).

Irritation hazards to workers via dermal contact were identified based on reactivity. 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 prepared by the new
chemical submitter, in a manner adequate to protect them. Risks were not evaluated for workers
for inhalation because exposures are not expected.

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 to the environment were not identified because the due to no releases to water.

Because worker exposures can be controlled by PPE, no unreasonable risks to the general
population or 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.

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TSCA Section 5(a)(3) Determination for Premanufacture Notice (PMN) P-19-0170

2/21/2020		Is/

Date:	Tala R. Henry, Ph.D.

Deputy Director for Programs

Office of Pollution Prevention and Toxics

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