UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
JUN I I 1986 .
MEMORANDUM
FROM:
TO:
OFFICE OF
PESTICIDES AND TOXIC SUBSTANCE?
SUBJECT: Data Needs Paper for the Aery Iate/MethacryI ate
Chemical Category
Wi I I iam Far land, Ph.D.
Ac t i ng Di rector
Health and Environmental
Rev i ew Di v i s i on (TS-796)
David Dul I
Ac t i ng Di rec tor
Chemical Control
Division (TS-794)
Attached is HERD'S proposal for the health and environmental effects section of
the Testing Recommendations/Data Needs for the Acrylate/Methacrylate chemical
category. We view this proposal as the basis for beginning negotiations with industry and
other groups interested in testing chemicals in this category. Clearly many of the details
of the testing plan still need to be determined. We expect that these testing details will
be discussed further and resolved once negotiations with the various interested parties
begin. We also believe that the data needs discussions and negotiations should be
undertaken in conjunction with discussions on our evaluation of the available toxicity
data on this category as presented in our earlier Position Paper.
In preparing our data needs proposal we have made several assumptions and
identified several considerations that should be made clear as our proposal is
incorporated into the regulatory strategy for the acrylate/methacrylate chemical
category. First, and perhaps most importantly, our testing proposal is designed to
provide a better understanding of the health and environmental effects of the
acrylate/methacrylate category as a whole. Our testing proposal may not necessarily
provide the basis for conducting quantitative risk assessments on specific members of the
category. We are viewing this proposal not in relation to a particular section of TSCA,
but as a means of qualitatively prioritizing OTS concerns for the spectrum of chemicals
within this broad category for use under all Sections of TSCA. This proposal must be
viewed in the context of answering some basic, broad questions on the hazards identified
with the category which will significantly improve our ability to assess these chemicals
in the various regulatory processes of TSCA. The data from this testing will focus our
regulatory emphasis on those chemicals that are likely to present the greatest hazard.
-------
The second major consideration in our testing proposal is the general lack of risk
and economic considerations in our proposal. Our proposal reflects primarily a hazard-
based perspective for identifying needed testing. We have not attempted to prioritize
the testing in our proposal with other types of testing that may be deemed desirable for
the category (e.g. epidemiology, fate, and exposure). These types of priorities need to be
considered as an Office-level decision.
Also, in our proposal we have generally not considered the relative risk from the
identified hazards of these chemicals because neither the exposure nor the dose-response
information is available at this time to quantitatively evaluate these risks. Without a
good measure of the relative hazard posed by members of the category, it is not possible
now for us to explicitly consider relative risk when determining the general nature or
scope of our testing proposal. Higher risk chemicals (or categories) might, for example,
warrent more extensive or rigourous testing than lower risk chemicals (or categories). It
may be best to address this issue as an Office-level policy decision where a more
comprehensive view of exposure and relative risk can be considered. In this forum,
additional information (e.g., exposure and economics) may be available to help balance
our hazard-based testing proposal against other types of testing needed for the category
and against the relative risk of these chemicals. These Office-level policy decisions may
require modifications to our attached testing proposal.
The third major consideration in our proposal is related to the sequence of testing
for the four areas of testing that we have identified (absorption, carcinogenicity,
neurotoxicity, and ecotoxicity). We suggest that the four areas not be combined into a
tiered scheme. Each area can be pursued as a separate line of investigation. However, it
may be logical to do the absorption testing early in the program, since this testing should
provide better insights into the limits of our health concerns for the larger molecular
weight category members.
We have also proposed a general approach for the other health effects testing.
For the neurotoxicity testing we expect that repeating the existing tests should be done
first to confirm these results before a broader range of chemicals is tested to answer our
basic category questions. In the carcinogenicity testing area we have identified the need
for genotoxicity data, modified bioassay data, and data from complete bioassays. Work
on expanding the genotoxicity data base is currently underway at the EPA lab at RTF.
We believe that work to develop data in both an acceptable rrwdified and a standard
bioassay should be started together., We are recommending that OTS use the data,
accepting the validity of both positive and negative results, developed in the modified
bioassay as it becomes available for regulatory decision-making and for identifying
additional chemicals to be tested in the complete bioassay. This modified bioassay data
should only be accepted, however, if data are simultaneously developed in a standard
bioassay. The standard bioassay results, that we expect will take longer to develop,
would then be used to validate the modifed bioassay design and the genotoxicity tests in
addition to providing a more scientifically acceptable way of evaluating the carcinogenic
potential of the category members.
Attachment
cc: W. Farland J. Du J. DeSantis S. Irene
M. May J. Gilford D. Klauder A. Blaschka
D. Beal G. Timm P. Hayes J. Merenda
B. Means V. Nabholz E. Falke K. Dearf ield
V. Turner M. Townsend . D. Gould T. Jones
A. Auletta M. Argus R. Brink C. Auer
-------
TESTING RECOMMENDATIONS/DATA NEEDS FOR THE
ACRYLATE/METHACRYLATE CHEMICAL CATEGORY
I. Introduction
The HERD Position Paper, The Health and Environmental Effects of Acrylate and
Methacrylate Chemicals and the Acrylate/Methacrylate Category, presents an evaluation
of the available toxicity information on this category of chemicals and attempts to
identify those areas where the data are limited or nonexistent. Questions about the
nature of the existing toxicity information should be directed to the "Position Paper",
since the present paper does not reexamine all this information. The purpose of the
"Data Needs Paper" is to more clearly identify the important areas ef uncertainty or
data gaps encountered during toxicity assessments of chemicals in this category and to
propose a testing strategy that will reduce the uncertainty of these assessments. It is
expected that this testing proposal will serve as an initial basis to begin negotiations with
interested parties. Further discussion with these parties will clarify and possibly modify
this proposal.
Based on the available toxicity data, there is a clear need for additional testing of
members of the acrylate/methacrylate category. The current dSta base, while providing
the basis for identifying several toxic effects of concern to the Agency, is relatively
limited with respect to predicting the relative hazard for the entire spectrum of
chemicals that fall within this category. Because of the relatively limited nature of the
database, decisions on chemicals in the category are often made based on extrapolations
and generalizations from the available data. These extrapolations and generalizations
lead to large uncertainties in our decisions.
HERD believes that the proposed testing will significantly improve our
understanding of the relative toxicity of chemicals in this category and more accurately
define the scope of the category for which toxicity concerns exist. Specifically we
-------
expect the test results to reduce the uncertainty of our assessments in several areas.
These areas include: (I) a better basis for determining the likelihood of human absorption
of these chemicals (i.e., defining the limits of our health concerns), (2) providing a
measure of the relative hazard for various subsets of the category, and (3) helping
prioritize our concerns for these chemicals for more detailed testing and regulatory
activity. To reduce the uncertainty of our assessments in these areas we expect the
testing results to answer some fundamental questions about the toxicity of this
category. These questions include:
I. What toxic effects are generally identified with chemicals in this category?
2. What is the relative hazard of acrylates vs. methacrylates for these toxic
effects?
3. What is the relative hazard of mono vs. multifunctional members for these
toxic effects?
4. What is the relative hazard of the larger motecular weight vs. smaller
molecular weight members?
5. What physico-chemical factors have the greatest affect on the dermal
absorption ->? these chemicals and what is the relationship between these
factors and ,e dermal absorption rate for these chemicals?
6. What is the importance of the exposure route in eliciting the health effects
of these chemicals?
-------
While the answers to these questions will significantly improve our understanding
of the toxicity of this category of chemicals, they may not necessarily provide the basis
for conducting quantitative risk assessments on specific category members. Different or
supplementary testing may also be needed to support quantitative risk assessment
decisions.
Based on the identified data gaps and uncertainties in our assessments, we are
proposing testing in four basic areas. These areas include:
I. Bioavailability/Absorption <- Because our understanding of the bioavailability
of acrylates/methacrylates is limited, OTS has been forced to rely on the
qualitatively observed absorption potential of specific category members as
an approximation of the general bioavailability of all category members. In
practice, this has resulted in our using the molecular weight (MW) of a
category member as the measure of its absorption potential. To do this we
ğ
have assumed an inverse relationship between MW and absorption potential
for category members. Empirical evidence is very limited for establishing a
particular molecular weight above which absorption does not occur or is not
biologically significant and for understanding the influence of other physico-
chemical factors (e.g., water solubility) on the absorption potential of these
chemicals. Systematically testing acrylates and methacrylates in a manner
which provides for careful control of physico-chemical properties would
immediately help to identify the most important factors and the
relationships between these factors and the absorption potential of category
members. This would be a large step toward more empirically defining the
extent or limits of our health concerns for category members.
-------
2. Carcinogenic Hazard Potential - Some members of this category have
produced a carcinogenic response in laboratory animals. However, the
relationship between chemical structure and this response is unknown
because of the relatively few category members actually tested. Also, it is
f
difficult to compare the available test results because few of the tests were
conducted using the same protocol. Additional testing would help define the
relationship between chemical structure and the inherent carcinogenic
activity of category members and assist in validating screening tests
designed to measure this carcinogenic activity more quickly and more
economically. Concurrent testing in a standard 2-year bioassay and in an
appropriate experimental modified bioassay would be critical to meeting
these objectives.
3. Neurotoxic Hazard Potential - The neurotoxicity concern for this category is
based on a very limited data set. Therefore, the basis for identifying this"
hazard with this category is weak. As a first step, HERD believes the
existing neurotoxic effect data should be confirmed by repeating the tests
that showed this effect by both the previously used routes of exposure and by
-Ğ
the route of expected human exposure. Depending on the results, a broader
range of category members might need to be tested to determine the
relative neurotoxic potential of chemicals in the category.
4. Ecotoxic Hazard Potential - The available ecotoxicity hazard data on
category members is limited to acute tests. Some category members have
L.C5Q values around I mg/L and show signs of chronicity, suggesting that
chronic exposures would produce toxic effects at concentrations much lower
than acute exposures. Additional testing on a broader range of category
-------
members would focus our concerns on particular subsets or individual
category members by providing data needed for establishing a quantitative
%
structure activity relationship (QSAR) and by determining the relationship
between acute and chronic toxicity values for this category of chemicals.
II. Proposed Testing Plans
A. Bioavailability/Absorption
I. Data Gaps
HERD has identified three basic data gaps in our understanding of the
bioavailability/absorption potential of fluid acrylate/methacrylate esters. The existence
of these data gaps has forced us to make certain assumptions about the
bioavailability/absorption of these chemicals that should be evaluated with additional
testing. This is an important area for testing because absorption potential is usually the
first area examined during the evaluation of category members in the new chemical
process. If, based on a member's physical form and physic-chemical parameters,
absorption is not considered likely, then the various health hazards are not expected to
be associated with that chemical.
The acrylate/methacrylate generic SNUR incorporates an absorption-based,
molecular weight definition of the category which places limits on the Agency's health
concerns for the category. In establishing this category definition and in assessing the
bioavailability/absorption potential of individual category members, the following assumptions
have been made:
-------
a) MW is inversely related to the absorption potential of category
members and can be used as an approximation of absorption
potential. Other physico-chemical factors such as water solubility
and octanol/water partition coefficient may also affect this
relationship and should be evaluated.
b) Absorption by the dermal or oral routes is expected to decrease with
increasing molecular weight in a manner such that at a molecular
weight of 1000 or greater the absorption potential of any category
member can be considered negligible.
c) Acrylate/Methacrylate esters with a MW of 500 or less are expected
to be absorbed to a significant degree when present at concentrations
of 2% or greater in fluid acrylate/methacrylate substances having a
number average molecular weight of greater than 1000.
2. Testing Proposal
-Ğr
Our testing proposal is designed to determine the relationship between physico-
chemical factors and bioavailability/absorption potential of these chemicals. It is
focused on providing information to evaluate the assumptions stated above that have
been part of our decision-making approach to assessing chemicals in this category. The
test plan is also focused on dermal absorption because this is the most frequently
identified exposure route during new chemical assessments. Our testing proposal
includes three components:
-------
a) To test the effect of molecular weight on the absorption of acrylates
and methacrylates, a homologous series of acrylates and
ğ
methacrylates could be synthesized where only the size and MW are
varied with a repeating unit. For example, a series of radiolabeled
polypropylene glycol diacrylates (PGDA) could be synthesized with a
range of propylene glycol units (=n). The smaller size members of the
series would be expected to be absorbed more readily than the larger
members of the series. The chemicals should be dermally tested neat
with a closed patch. Measurements of radioactivity should be made in
urine samples and samples of subcutaneous tissues at the site of
application. A sufficient number of members in thieveries should be
tested to define the relationship between MW and absorption. Ideally,
enough larger MW members should be tested to identify a plateau or
asymptote where further increases in MW do not significantly reduce
absorption. Selected methacrylate esters should then'be tested to
determine any differences in absorption between acrylates and
methacrylates.
-Ğ
b) Once the general relationship between MW and absorption has been
established for acrylates and methacrylates, the effect of varying
water solubility and octanol/water partition coefficient at a given
MW siioijld be evaluated. This might be done by comparing the
absor >n of PGDA and a more water soluble polyethylene glycol
diacr/l ;te of similar MW.
-------
c) We also propose testing to evaluate the importance of concentration
in assessing absorption potential of low MW acrylates/methacrylates
from a fluid high acrylate/methacrylate material. For example, radio-
labeled neopentyl glycol diacrylate (NPGDA, MW=2I2) could be
synthesized and tested neat in the same protocol as above to establish
its relative absorption in this test. A large PGDA-n could also be
synthesized with n such that the chemical will have only negligible
absorption using the protocol stated above. The labeled NPGDA could
then be mixed with the PGDA-n at concentrations above, below, and
at 2% and the absorption of labeled NPGDA measured in the protocol
listed above.
A determination of a reasonable cutoff for the percent of low MW
species in high MW acrylate/methacrylate substances could then be
based on this absorption data.
*
3. Data Use
The results of these tests will provide a better basis for:
(a) .Understanding the relationship between MW and absorption.
(b) Identifying other physico-chemical factors that significantly affect
the absorption of these chemicals.
(c) Understanding the absorption potential of lower MW constituents in a
, higher MW mixture.
8
-------
(d) Defining the range of physico-chemical factors for category members
beyond which we expect that aerylate/methacrylate chemicals will
not be absorbed to a significant degree and thus will not pose a health
r
risk to humans.
These data will be used to provide an empirical basis for defining the range of
category members that should be expected to be absorbed by humans and that may
present a health risk to humans. Acrylates or methacrylates with physico-chemical
properties outside the category limit will not be expected to be absorbed to a significant
extent by humans and, therefore, should not be expected to present a health risk to
humans. When combined with more detailed information on the potential health effects,
an improved understanding of the absorption of these chemicals will eventually also
improve our ability to assess the relative risk of specific category members.
*
B. Carcinogenic Hazard Potential
I. Data Gaps
Based on our review of the available data on the carcinogenicity of category
members, there are two basic data gaps associated with a category-wide understanding
of the carcinogenicity of acrylates/methacrylates. First, the available test data were
generated from a chemical specific perspective and do little to help answer our basic
questions about the category as a whole. For example a measure of the relative
carcinogenic hazard of acrylates vs. methacrylates, mono vs. multifunctional, and the
larger vs. smaller MW category members cannot be generated from the existing data.
Second, the available data were derived from significantly different protocols, making
-------
comparisons of the results difficult. We are currently unable to determine how reliable
the available modified bioassay studies are in detecting the inherent carcinogenic
*
potential of these chemicals. Therefore, one of the objectives of a testing program for
this category should be the validation of a modified bioassay which could be used to
economically screen chemicals containing the aerylate/methacrylate functional groups
for their potential carcinogenic!ty. To most effectively accomplish this objective,
results generated in a standard 2-year bioassay on a carefully selected series of category
members should be compared with the results from an appropriate modified bioassay on a
more extensive set of category members. The data generated in both assays will be
useful in describing the relative carcinogenic hazard of chemicals within the category.
2. Testing Proposal
Currently there are no validated in vitro or in vivo carcinogenicity screening tests
for this category of chemicals. Therefore, the most scientifically acceptable way to
evaluate the inherent carcinogenic potential of category members is to test them in a
standard two-year bioassay. A validated screening tool would be a valuable tool to help
answer questions about the relative carcinogenic hazard ^of the category and for
screening the carcinogenic potential of "new" category members. As a result, there is a
need for developing data from both a standard bioassay and a screening assay. EPA is
currently developing data from genotoxicity assays for this category, so our testing
proposal focuses on data development from both the standard bioassay and a modified,
screening bioassay.
10
-------
Because of the category approach to evaluating these chemicals, HERD proposes
the concurrent development of data in an acceptable modified bioassay protocol and ine
Ğ
a standard bioassay. The results of the modified bioassay would provide a cost-effective
basis for evaluating and screening a range of category members', whereas the results of
the standard bioassay would be used to validate the design of the modified bioassay.
The specific protocol design for both the modified and standard bioassays for this
testing should be developed in consultation with interested parties. We believe the main
uncertainty in the design of these tests is the route of administration for the test
substance. Inhalation does not appear appropriate because only low doses can be
administered, and drinking water studies would be complicated by hydrolysis of the test
substance. For human risk assessment purposes, the primary route of expected human
exposure (dermal for this category) should be used. However, because of the irritating
properties of category members it may be difficult to reach an appropriate MTD by this
route or to generate a dose-response curve by testing over a range of doses. The dermal
route has, however, yielded several positive results in single dose, limited bioassays. The
gavage route, while not the route of human exposure does have certain advantages over
the dermal route in this case. First, the gavage route allows higher doses to be
administered in a more precise manner. Second, dosing by^javage can be done more
frequently. Third, irritation appears to be less of a problem with the gavage route, but it
is still a major difficulty. However, the gavage route is clearly not the expected route of
human exposure.
In addition to determining the route of exposure for both a modified and the
standard bioassays, several other important aspects of the modified bioassay need to be
defined to ensure it is an acceptable test. These factors include: the amount of
histopathology, the study duration, number of animals, etc. The major consideration in
defining these details will be the trade-off between the sensitivity of the test and the
test cost. The use of statistical analyses may help in evaluating the effect of the
various test options on the power of the modified bioassay protocol.
-------
The selection of specific chemicals for testing will also need to be resolved
following further discussions with the interested parties. Tables I and 2 present a list of
Ğ
category members from which those to be tested could be selected. The specific
chemicals selected should be designed to answer our basic questions about the category
and to maximize the use of the available data and resources.
3. Data Use
The most important use of this data will be to provide the Agency with a data set
that accurately represents the inherent carcinogenic potential of the tested category
members. These data will provide the basis for distinguishing the relative carcinogenic
activity of subsets of this category by providing a reasonable degree of confidence that
negative results indicate a true lack of carcinogenic activity. These data will also
provide an acceptable basis or baseline for validating modified bioassay and genotoxicity
test results that may be useful to screen a wider range of "existing" and "new"
acrylate/methacrylate chemicals. These results will enable us to focus our attention on
those members or subsets of the category that present the greatest carcinogenic hazard.
-Ğr
C. Neurotoxic Hazard Potential and Other Chronic Effects
I. Data Gaps
The available neur toxicity hazard data for this category of chemicals is very
limited. It consists primarily of one study on 2-hycfroxyethyl acrylate (2-HEA), one study
on a methacrylate mixture, and several case reports of methacrylate exposures to
humans. Neurotoxicity effects have been observed in so few studies that extrapolation
to the entire category is not possible with a reasonable degree of certainty. Two basic
12
-------
data gaps are apparent from our evaluation of the available data.
* a) Because it is possible that the positive neurotoxicity results
reported are false positives, there is a need to retest the
chemicals previously studied with a standard protocol to
confirm the existence of the neurotoxic effect.
b) Given the confirmation of the neurotoxic effects for the
previously tested chemicals, a wider range of category
members would then be tested. These additional tests will help
answer questions about the relative neurotoxic hazard within
the various subsets of the category (e.g. acrylates vs.
methacrylates, mono vs. multifunctional, larger MW vs.
smaller MW members).
In addition to evaluating neurotoxic effects in these studies, it would be valuable
to also look for any other chronic effects (non-carcinogenic). The available data that
specifically included observations for other effects are very limited for this category,
although no other specific effects have been noted in the available studies.
2. Testing Proposal
The neurotoxicity testing should be a tiered approach designed to first confirm the
available results, and then to develop additional data if the first tier is positive.
a) As the first proposed tier of testing, 2-HEA should be retested
in a 90-day subchronic study using the OTS text guidelines on
13
-------
the functional observational battery and neuropathology. Also,
methyl methacrylate, penfaerythritol triacrylate, trimethylol
ğ
propane trimethyacrylate, trimethylol propane triacrylate, and
tripropylene glycol diacrylate should be tested in a 90-day
subchronic study to confirm the reported neurotoxic effects
for these chemicals. The route of exposure should be
identified based on many of the same considerations identified
in the carcinogenicity discussion.
b) If a neurotoxic effect can be confirmed in at least some of the
studies listed above, additional studies should be performed.
These additional studies should involve a 90-day subchronic
protocol using OTS test guidelines on the functional
observational battery and neuropathology. Chemicals for
testing should be selected from Tables I and 2 to help answer
questions of the relative hazard of acrylates vs. methacrylates,
mono vs. multifunctional, and the larger MW vs. smaller MW
category members and to maximize the use of the available
data on this effect. Signs of other chronic (non-carcinogenic)
effects should be assessed in all the neurotoxicity studies.
3. Data Use
The results of the testing proposal will be used by the Agency in several ways.
First, it will allow us to confirm or reject the identification of a neurotoxicity hazard
with this category of chemicals. Second, if this hazard identification is confirmed it will
allow us to prioritize our concerns for a wider range of category members by identifying
-------
those that present the greatest hazard. Third, it will help identify other chronic effects,
if any, that should be associated with this category of chemicals.
Ğ
D. Ecotoxic Hazard Potential
I. Data Gaps
The available ecotoxicity data on this category of chemicals are primarily from
acute toxicity tests. These results indicated acute LC5Q values as low as I mg/L and
indicated signs of chronicity, which suggests that chronic effect concentrations may be
much lower (one-twentieth or less) than acute effect concentrations. These data, which
identify an ecotoxicity hazard concern, require further evaluation to answer some basic
questions about the nature of the effect for a wider range of category members. These
questions include the relative hazard of acrylates vs. methacrylates, mono vs.
multifunctionals, smaller MW vs. larger MW members, the effect of acr^late equivalent
weight (i.e., total MW divided by the number of acrylate functional groups), and the
effect of other functional groups. Testing on fish, daphnia, and algae is also needed to
evaluate the relative sensitivity among the basic groups of aquatic organisms.
2. Testing Proposal
Our ecotoxicity testing proposal involves the selection of acrylate chemicals from
Table 2 and methacrylate chemicals from Table 3 in addition to larger prepolymers
(MW ^ 1000) that will answer our basic questions identified above. It is proposed that
each chemical selected be tested in an acute fish, acute daphnid, and algal toxicity
tests. If the 96-hour EC$Q value for fish or the 48-hour ECjQ value for daphnids is less
than I mg/L then the appropriate chronic toxicity testing should be done. However, if
-------
the acute EC^Q values are greater than I mg/L but less than 100 mg/L and there is
evidence of cumulative toxicity (i.e., the fish 24-hour EC^Q/96-hr EC$Q ratio or the
daphnid 24-hour ECjQAB-hour EC^Q ratio is greater than two), then the proposed chronic
toxicity testing should also be done. The proposed chronic toxicity testing is the fish
early life stage toxicity test and the daphnid chronic toxicity test.
3. Data Use
These data will allow the Agency to develop a QSAR between acute toxicity and
physico-chemical properties, to determine whether certain functional groups or category
subsets present a greater or lesser aquatic toxicity hazard, and to determine the limits of
our aquatic toxicity concern for the category based on MW, acrylate equivalent weight,
and water solubility. This will allow us to focus our attention on those category members
that appear to present the greatest ecotoxcity hazard.
16
-------
Table 1. Acrylate candidates for health and ecotoxicity testing
ACID
acrylic acid
ğ
MONOACRYLATES
methyl acrylate
allyl acrylate
propyl acrylate
_rv-butyl acrylate
pentyl acrylate
jv-octyl acrylate
2-ethylhexyl acrylate
decyl acrylate
dodecyl acrylate
CYCLIC MONOACRYLATES
phenyl acrylate
benzyl acrylate
isobornyl acrylate
HYDP.OXY-SUBSTITUTED MONOACRYLATES
Hydroxypropyl acrylate
ALKOXIDE-SUBSTITUTED MONOACRYLATES
methoxy acrylate
butoxyethyl acrylate
PHENOXIDE-SUBSTITUTED MONOACRYLATES
phenoxyethyl acrylate
EPOXY-SUBSTITUTED MONOACRYLATES
glycidyl acrylate
NITRO-SUBSTITUTED MONOACRYLATES
2, 2-dinitropropyl acr.'.ate
AMINO-SUBSTITUTED MO'. 'CRYLATES
dimethylaminoethyl ae:vlates
CYANO-SUBSTITUTED MOr" -\CRYLATES
2-cyanoethyl acrylate
17
-------
Table 1. (continued)
HALOGENATED MONOACRYLATES
2,3-Dichloropropyl acrylate
tribromophenyl acrylate
2,2,2-trifluoroethyl acrylate
3 r 3,4,4,4-pentafluorobutyl acrylate
nonafluorohexyl acrylate
tridecylfluorooctyl acrylate
heptadecylfluorodecyl acrylate
pentacosafluorotetradecyl acrylate
POLYACRYLATES
ethyleneglycol diacrylate
1,4-butanediol diacrylate
diethyleneglycol diacrylate
1,6-hexanediol diacrylate
tetraethyleneglycol diacrylate
trimethylolpropane triacrylate
pentaerythritol tetraacrylate
dipentaerythritol pentaacrylate
18
-------
Table 2. Methacrylate candidates for health and ecotoxicity
testing.
ACID
methacrylic 4acid
MONOMETHACRYLATES
methyl methacrylate
allyl methacrylate
propyl methacrylate
butyl methacrylate
2-ethylbutyl methacrylate
octyl methacrylate
ethylhexyl methacrylate
jv-decyl methacrylate
lauryl methacrylate
CYCLIC MONOMETHACRYLATES
phenyl methacrylate
benzyl methacrylate
HYDROXY-SUBSTITUTED MONOMETHACRYLATES
Hydroxypropyl methacrylate
ALKOXIDE-SUBSTITUTED MONOMETHACRYLATES
methoxyethyl methacrylate
2-(vinyloxy)ethyl methacrylate
PHENOXIDE-SUBSTITUTEP MONOMETHACRYLATES
2-phenoxyethyl methacrylate
EPOXY-SUBSTITUTED MONOMETHACRYLATES '
glycidyl methacrylate
NITRO-SUBSTITUTED MONOMETHACRYLATES
2,2-dinitropropyl methacrylate
AMINO-SUBSTITUTED MONOMETHACRYLATES
NfN-dimethylaminoethvl methacrylates
CYANO-SUBSTITUTED MONOMETHACRYLATES
2-isocyanotomethyl methacrylate
19
-------
Table 2. (continued)
HALOGENATED MONOMETHACRYLATES
2-chloroethyl methacrylate
trifluoroethyl methacrylate
2,2,3,3,3-pentafluoropropyl raethacrylate
3,3,4,4,5,5,6,6-nonafluorohexyl methacrylate
lH,lH-pentadecafluorooctyl methacrylate
POLYMETHACRYLATES
ethyleneglycol dimethacrylate
1,3-butanediol dimethacrylate
diethyleneglycol dimethacrylate
aluminum trimethacrylate
ADDITIONAL METHACRYLATES
tributyltin methacrylate
3-(trimethoxysilyl) propyl methacrylate
thioglycidyl methacrylate
vinyl methacrylate
20
------- |