Ethyl acrylate

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

Study period:

17 Apr - 19 Apr 1989

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study conducted in compliance with GLP regulations

Qualifier:

according to guideline

Guideline:

EPA OTS 797.1300 (Aquatic Invertebrate Acute Toxicity Test, Freshwater Daphnids)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

- Concentrations: The measured concentrations of EA in test water were determined at 0 and 48 hours of the test. All concentrations and the control were sampled and analyzed.
- Sampling method: At each sampling period, 5 mL aliquots of test water were collected from replicates A - D of each test solution. Replicates A and C were combined to yield a 10 mL sample. Likewise, replicates B and D were combined.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: the proportional diluter system used was calibrated prior to testing by checking volume deliveries from the diluter mixing cell to obtain a dilution factor used for stock preparations. The diluter system was set to provide levels at approx. 50 % dilutions of each other. Volume deliveries were also collected for each test replicate to assure all test levels were within ± 10 % of the mean volume delivery.
- Controls: dilution water control
- Evidence of undissolved material (e.g. precipitate, surface film, etc): no

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Source: Primary culture from the Columbia National Fisheries Research Laboratory, Missouri; in-house daphnid culture since 1977 culture at ABC Laboratories
- Age at study initiation (mean and range, SD): first-instar (<= 24 hrs old)
- Feeding during test: none



ACCLIMATION
- Acclimation period: no acclimation necessary

Test type:

flow-through

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

none

Hardness:

170 - 174 mg/L

Test temperature:

19 - 20 °C

pH:

7.7 - 7.8

Dissolved oxygen:

6.9 - 7.6 mg/L

Salinity:

-

Nominal and measured concentrations:

Nominal test concentrations: 0.90, 1.8, 3.8, 7.5 and 15 mg/L
Mean measured concentrations: 0.75, 1.7, 3.4, 6.3 and 12 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type (delete if not applicable): open
- Material, size, headspace, fill volume: 1 L-glass beakers with notched drains which were covered with 50-mesh stainless steel screen to prevent escape of the daphnids
- Aeration: no
- Type of flow-through: A half-liter proportional diluter system described by Mount and Brungs (Water Res. 1: 21-29, 1967) utilizing a Hamilton Micro Lab 420 syringe dispenser was used for the intermittent introduction of dilution water and EA into the test chambers. the system contained 6 sets of four replicate one-liter test chambers, designated as control, and level #1 through level #5. Flow-splitting chambers were utilized to thoroughly mix and divide each test concentration for delivery to the test chambers.
- Renewal rate of test solution (frequency/flow rate): Average rate of 4.2 mL/chamber/min, an amount sufficient to replace the 1L-test volume 6 times/24 hrs
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- Biomass loading rate: approx. 1 daphnid/100 mL


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: The dilution water used was a blend of reverse osmosis water and ABC well water.
- Total organic carbon: < 1.0 ppm
- Particulate matter: 0.30 ppm
- Pesticides: < 0.1 ppb
- Chlorine: < 0.05 ppm
- Alkalinity: 184 - 205 mg/L as CaCO3
- Conductivity: 325 - 420 µMHOS/cm



OTHER TEST CONDITIONS
- Photoperiod: 16-hrs daylight/8-hrs darkness with 2 30-min transition periods
- Light intensity: cool white fluorescent light bulbs at 50-70 ft. c. intensity


EFFECT PARAMETERS MEASURED (with observation intervals if applicable): Water quality parameters of temperature, dissolved oxygen, and pH were measured in each concentration at 0 and 48 hrs. All concentrations were observed at 4, 24, and 48 h for immobilization and other abnormal effects such as surfacing, erratic movement and/or daphnids laying on the bottom.


TEST CONCENTRATIONS
- Spacing factor for test concentrations: ca. 2
- Range finding study
A static, 48-h range-finding test was conducted in April 1989.
- Test concentrations: 0.1, 1.0, 10, and 100 mg/L
- Results used to determine the conditions for the definitive study: At 10 and 100 mg/L 100 % of the daphnids had been immobilized after 48 h.

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

3.4 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

7.9 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Behavioural abnormalities: no abnormalities other than immobilization observed
- Mortality of control: no
- Other adverse effects control: no
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: no

Prior to the initiation of the Daphnia magna toxicity test, a method validation was conducted to determine the recovery of EA in test water. Fortification concentrations ranged from 0.253 to 101 mg/L and yielded an average recovery of 100 ± 8.9 %.

Percent immobilization:

Mean meas. conc. [mg/L]	4 h	24 h	48 h
Control	0	0	0
0.75	0	0	0
1.7	0	0	0
3.4	0	0	0
6.3	0	0	15
12	0	45	100

The mean measured concentrations calculated from analytical sampling at 0 and 48 hours were as follows: 0, 0.75, 1.7, 3.4, 6.3, and 12 mg/L. Overall, these measured values represent 86 ± 5.5 % of the nominal concentrations (recovery between 80 and 94 %).

At 24 hours, 45 % of the daphnids at 12 mg/L were immobilized. At 48 hours, 100 % of the daphnids at 12 mg/L and 15 % at 6.3 mg/L respectively were immobilized. Based on the mean measured test concentrations, the 48-hour EC50 was 7.9 mg/L and the NOEC was 3.4 mg/L.

Validity criteria fulfilled:

yes

Description of key information

Ethyl acrylate is acutely toxic to freshwater invertebrates.
EC50 (48 h) = 7.9 mg/L (measured), (Daphnia magna, EPA OTS 797.1300, flow through)

As described in section 13.2 of IUCLID, testing information is consistent with six acrylic esters evaluated as a category.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

7.9 mg/L

Additional information

An acute toxicity study with Daphnia magna (BAMM, 1990) indicated the 48-hour EC50 was 7.9 mg/L based on measured concentrations. This study followed EPA OTS Guideline 797.1300 using a flow-through design. Nominal exposure concentrations ranged from 0.90 to 15 mg/L and mean measured concentrations ranged from 0.75 to 12 mg/L. Immobilization occurred in the two highest concentrations (6.3 and 12 mg/L, measured).

In a short-term test with Daphnia magna conducted according to EEC guideline a 48-hour EC50 of 4.41 mg/L was found (BASF AG, 1989). The given effects values are related to nominal concentrations. The possible decrease in test concentration by volatilisation of the substance was not considered.

Data on acute toxicity of ethyl acrylate on marine invertebrates are scarce. Price et al. (1974) conducted a static toxicity test on brineshrimp. No guideline was followed and no analytical monitoring performed. Since EA is readily biodegradable, undergoes slow hydrolysis in water and is rather instable against light, the test results cannot be used for the hazard assessment for marine invertebrates.

In addition, a robust data set of acute studies is available from the other members of the acrylic ester category (methyl, 2-ethylhexyl, n-butyl, isobutyl, and tert-butyl acrylate).