2-(2-methoxyethoxy)ethyl methacrylate

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 850.1010 (Aquatic Invertebrate Acute Toxicity Test, Freshwater Daphnids)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

Test water samples were collected from the batches of test solution prepared for each treatment and control group at the beginning of the test, and from two of the four replicate test chambers in each treatment and control group at 48 hours (± 1 hour) to measure concentrations of the test substance. Samples (8.0 mL) were collected from mid-depth, placed in glass vials containing 2.0 mL of 0.5% formic acid in methanol and processed immediately for analysis.

Frequency at t=0 h and t=48 h
Volume 4.8 mL from the approximate centre of the test vessels
Storage Samples were stored in a freezer (≤-15°C) until analysis at the analytical laboratory of the Test Facility.

At the end of the exposure period, the replicates were pooled at each concentration before sampling.

Additionally, reserve samples of 4.8 mL were taken for possible analysis. If not used, these samples were stored in a freezer (≤ -15°C) for a maximum of three months after delivery of the draft report, pending on the decision of the sponsor for additional analysis.

Vehicle:

no

Details on test solutions:

A primary stock solution was prepared by mixing a calculated amount of test substance in 2 L of dilution water for a nominal concentration of 100 mg a.i./L, the highest concentration tested. The stock solution concentration was adjusted to 100% active ingredient during preparation, based on the reported test substance purity (99.84%). The stock solution was brought to partial volume and sonicated for 15 minutes. It was then brought to final volume and stirred on a magnetic stir plate using a Teflon®-lined stir bar for 15 minutes, and appeared clear and colorless with no visible precipitates. Aliquots of the primary stock solution were proportionally diluted with dilution water to a final volume of 1 L to prepare four additional test solutions at nominal concentrations of 6.3, 13, 25 and 50 mg a.i./L. The solutions were stirred on a magnetic stir plate using a Teflon®-lined stir bar for 15 minutes, and approximately 220 mL of solution was placed in each of four replicate test chambers per treatment group.

Test organisms (species):

Daphnia magna

Details on test organisms:

The cladoceran, Daphnia magna, was selected as the test species for this study. This species is representative of an important group of aquatic invertebrates and was selected for use in the test based upon past history of use in the laboratory. Daphnids used in the test were <24-hour old neonates obtained from cultures maintained by EAG Laboratories in Easton, Maryland. Identification of the species was verified by the supplier of the original stock culture.
Daphnids in the cultures were fed daily a mixture of yeast, cereal grass media and trout chow (YCT), supplemented with a vitamin stock solution and a suspension of the freshwater green alga, Raphidocelis subcapitata. The adults were fed during the 24-hour period prior to test initiation, but neonates were not fed during the test.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Post exposure observation period:

Not applicable

Hardness:

Not stated

Test temperature:

20.0 – 20.7°C

pH:

7.9 – 8.5

Dissolved oxygen:

≥ 97%; no aeration

Salinity:

Not stated

Conductivity:

Not stated

Nominal and measured concentrations:

Nominal concentrations selected for use in this study were 6.3, 13, 25, 50 and 100 mg a.i./L. Test solutions in the test chambers at these nominal concentrations appeared clear and colorless during the test, with no evidence of precipitation observed.
Measured concentrations of the samples ranged from approximately 92.9 to 98.8% of nominal. When measured concentrations of the samples were averaged, the mean measured test concentrations for this study were 6.1, 13, 24, 49 and 97 mg a.i./L, representing 97, 100, 96, 98 and 97% of nominal concentrations, respectively. The results of the study were based on the nominal concentrations.

Details on test conditions:

Daphnids were exposed to a geometric series of five test concentrations and a negative control (dilution water) for 48 hours under static conditions. Four replicate test chambers were maintained in each treatment and control group, with five daphnids in each test chamber, for a total of 20 daphnids per concentration. Nominal test concentrations were selected in consultation with the Sponsor based on exploratory range-finding toxicity data. Nominal test concentrations selected were 6.3, 13, 25, 50 and 100 mg active ingredient (a.i.)/L. Test concentrations were measured in samples of test water collected from each treatment and control group at the beginning and the end of the test. Results of the analyses were used to calculate mean measured test concentrations.

Reference substance (positive control):

no

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

Nominal test concentrations selected were 6.3, 13, 25, 50 and 100 mg active ingredient (a.i.)/L. Test concentrations were measured in samples of test water collected from each treatment and control group at the beginning and the end of the test. Results of the analyses were used to calculate mean measured test concentrations.

 

 

Validity criteria fulfilled:

yes

Conclusions:

The cladoceran, Daphnia magna, was exposed for 48 hours under static conditions in an OECD TG 202 study to five nominal concentrations of 2-(2-methoxyethoxy)ethyl methacrylate (CAS 45103-58-0) ranging from 6.3 to 100 mg a.i./L. Based on the nominal concentrations, the 48 hour EC50 value was >100 mg a.i./L, the highest concentration tested.
The 48 hour no-immobility concentration and the NOEC were both 100 mg a.i./L.

Executive summary:

In accordance with  OECD TG 202 following GLP conditions, the cladoceran, Daphnia magna, was exposed for 48 hours under static conditions in an OECD TG 202, to five nominal concentrations of 2-(2-methoxyethoxy)ethyl methacrylate (CAS 45103-58-0) ranging from 6.3 to 100 mg a.i./L.  Based on the nominal concentrations, the 48 hour EC50 value was >100 mg a.i./L, the highest concentration tested.

The 48 hour no-immobility concentration and the NOEC were both 100 mg a.i./L.

Description of key information

The cladoceran, Daphnia magna, was exposed for 48 hours under static conditions in an OECD TG 202  study, under GLP conditions, to five nominal concentrations of 2-(2-methoxyethoxy)ethyl methacrylate (CAS 45103-58-0) ranging from 6.3 to 100 mg a.i./L.  Based on the nominal concentrations, the 48 hour EC50 value was >100 mg a.i./L, the highest concentration tested.

The 48 hour no-immobility concentration and the NOEC were both 100 mg a.i./L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

100 mg/L

Marine water invertebrates

Marine water invertebrates

Effect concentration:

100 mg/L