methyl acrylate; methyl propenoate

Long-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

fish early-life stage toxicity

Type of information:

experimental study planned

Justification for type of information:

TESTING PROPOSAL ON VERTEBRATE ANIMALS
NON-CONFIDENTIAL NAME OF SUBSTANCE:
Name of the substance on which testing is proposed to be carried out: Methyl acrylate, EC Number: 202-500-6, CAS Number: 96-33-3.
- Name of the substance for which the testing proposal will be used [if different from tested substance]: not applicable

CONSIDERATIONS THAT THE GENERAL ADAPTATION POSSIBILITIES OF ANNEX XI OF THE REACH REGULATION ARE NOT ADEQUATE TO GENERATE THE NECESSARY INFORMATION:
- Available GLP studies: No GLP studies are available to fulfill this endpoint.
- Available non-GLP studies: No non-GLP studies on long-term toxicity to fish are available.
- (Q)SAR: No QSARs are available to predict reliable fish chronic effect levels.
- In vitro methods: No in vitro methods are available to fulfill this endpoint.
- Weight of evidence and Grouping and read-across: Within the lower acrylates category no studies are available in support of fulfilling this endpoint. By now, there are no data available on long-term toxicity to fish for any of the lower acrylates, however an OECD TG 210 is in parallel proposed for 2-ethylhexyl acrylate (EC Number 203-080-7, CAS Number 103-11-7). In order to perform an adequate interpolation for read-across within the lower acrylate category for the endpoint long-term fish toxicity, we propose to perform also an OECD 210 with Methyl acrylate in addition to 2-ethylhexyl acrylate. For this endpoint, a waiving according to ECHA Guidance on information requirements and chemical safety assessment (version 3.0, June 2017), Chapter R7b (Section R.7.8.5., including Figure R.7.8-4) was performed, considering that: If based on acute aquatic toxicity data neither fish nor invertebrates are shown to be substantially more sensitive, long-term studies may be required on both. In such case, according to the integrated testing strategy, the Daphnia study is to be conducted first. Acute effects levels were in the same range of concentrations for all three aquatic trophic levels, i.e. between 1 and 10 mg/L. In order to assess long-term toxicity towards aquatic organisms, 21-day chronic life-cycle studies with Daphnia magna were conducted with the structurally related n-butyl acrylate (NOEC reproduction 0.136 mg/L, OECD 211, semi-static); ethyl acrylate (NOEC reproduction 0.19 mg/L, EPA OTS 797.1330, flow-through); and 2-Ethylhexyl acrylate (EC10 reproduction 0.85 mg/L TWM, OECD 211, semi-static). For Methyl acrylate, the long-term aquatic invertebrate endpoint was filled by read-across from the NOEC of 0.136 mg/L. Considering the results and the application of a relevant assessment factor, no risks were observed (PEC/PNEC<1) therefore the long-term fish testing has been waived so far. Based on BoA decisions this waiving argument is not accepted anymore, therefore the long-term fish study according to OECD TG 210 is proposed.
- Historical human data: not relevant
- Substance-tailored exposure driven testing [if applicable]: not applicable
- Approaches in addition to above [if applicable] not applicable
- Other reasons [if applicable] not applicable

CONSIDERATIONS THAT THE SPECIFIC ADAPTATION POSSIBILITIES OF ANNEXES VI TO X (AND COLUMN 2 THEREOF) OF THE REACH REGULATION ARE NOT ADEQUATE TO GENERATE THE NECESSARY INFORMATION:
Long-term toxicity testing on fish (preferably the ELS study) is a standard information requirement according to REACH Annex IX 9.1.6. The recently proposed REACH amendments indicate that this endpoint is not subject to Column 2 adaptation.
FURTHER INFORMATION ON TESTING PROPOSAL IN ADDITION TO INFORMATION PROVIDED IN THE MATERIALS AND METHODS SECTION:
Details on study design / methodology proposed [if relevant] The proposed study will follow the methodology described in the test guideline OECD 210 Fish, Early-life Stage Toxicity Test, including analytical determination of the concentrations of the test substance. For the selection of the test concentrations, the results from the exixting studies on acute and prolonged toxicity to fish will be considered. In addition, a range finding test might be conducted to determine the test concentrations for the definitive test. The exposure system will be defined considering the characteristics of the substance such as phys-chem properties and stability according to the recommendations by the OECD GD 23.
Proposed test guideline: according to the OECD 210 Fish, Early-life Stage Toxicity Test
Species: a species recommended by the OECD TG 210 such as medaka will be selected.
Discussion
Key Information:
No longer term toxicity test results with fish are available for Methyl acrylate, EC Number: 202-500-6, CAS Number: 96-33-3.
Relevant studies: Long-term toxicity to aquatic fish - testing proposal
Additional information:
Methyl acrylate is readily biodegradable and has low potential for bioaccumulation (determined log Pow of 0.739 and calculated BCF value of 3.16). Fish, invertebrate and algae showed a comparable sensitivity to Methyl acrylate in short-term toxicity studies. Long-term toxicity testing on fish (preferably the ELS study) is a standard information requirement according to REACH Annex IX 9.1.6. The recently proposed REACH amendments indicate that this endpoint is not subject to Column 2 adaptation.

Qualifier:

according to guideline

Guideline:

OECD Guideline 210 (Fish, Early-Life Stage Toxicity Test)

Deviations:

no

GLP compliance:

yes

Description of key information

A testing proposal is submitted for long-term toxicity to fish testing of Methyl acrylate (EC Number: 202-500-6, CAS Number: 96-33-3). In addition of being used for the substance itself, the testing proposal will also be applied in support of read-across for the Lower Alkyl Acrylates category members (except Acrylic acid).

Additional information

The use of methyl acrylate as a monomer, almost exclusively in closed systems for the production of copolymers with other monomers such as acrylic acid and its salts, amides, esters, methacrylates, acrylonitrile etc., indicates that environmental exposure would be limited. The volatility of methyl acrylate provides for volatilization of any releases to the air. Methyl acrylate is readily biodegradable, has low potential for bioaccumulation, and is slowly photodegradable. Accidental releases to the environment would not result in accumulation or persistence. The relatively high water solubility and corresponding low log Kow indicate that no bioaccumulation potential exists.  

Acute effects levels were in the same range of concentrations for all three trophic levels, i.e. between 1 and 10 mg/L.  In order to assess long-term toxicity towards aquatic organisms, 21-day chronic life-cycle studies with Daphnia magna were conducted with the structurally related n-butyl acrylate (NOEC reproduction 0.136 mg/L, OECD 211, semi-static); ethyl acrylate (NOEC reproduction 0.19 mg/L, EPA OTS 797.1330, flow-through); and 2-Ethylhexyl acrylate (EC10 reproduction 0.85 mg/L TWM, OECD 211, semi-static). For Methyl acrylate, the long-term aquatic invertebrate endpoint was filled by read-across from the NOEC of 0.136 mg/L. Considering the results and the application of a relevant assessment factor, no risks were observed (PEC/PNEC<1).

Therefore the long-term fish testing has been waived so far. Still, long-term toxicity testing on fish (preferably the ELS study) is a standard information requirement according to REACH Annex IX 9.1.6. The recently proposed REACH amendments indicate that this endpoint is not subject to Column 2 adaptation. A testing proposal has been submitted for long-term toxicity to fish testing of Methyl acrylate (EC Number: 202-500-6, CAS Number: 96-33-3). In addition of being used for the substance itself, the testing proposal will also be applied in support of read-across for the Lower Alkyl Acrylates category members (except Acrylic acid).