Ethyl acrylate

Long-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

04.10. - 25.10.1996

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 797.1330 (Daphnid Chronic Toxicity Test)

Principles of method if other than guideline:

GLP study with the following exception:  food analyses were not done under GLP regulations.

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

- Concentrations: Control (0.0), 0.38, 0.75, 1.5, 3.0, and 6.0 mg/L
- Sampling method: Samples were collected during the equilibration period on day -1, and during the in-life phase on days 0, 4, 7, 11, 14, 18, 19 and 21. The concentrations of ethyl acrylate were determined by analysis of 10-mL samples collected from duplicate replicates from the control and each test level using a 10-mL Class A volumetric pipet.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Diluter stock solutions of 1500 mg Ethyl Acrylate/L for use in the definitive study were prepared by transferring approximately 3.0060 g of Ethyl Acrylate to a 2-L volumetric flask which was then brought to volume with ABC reagent water. An injection of 4.0 mL of the diluter stock solution (1500 mg/L) was delivered to the 1-L mixing box by a Hamilton Model 420 dual syringe dispenser each time the diluter cycled.
This dilution resulted in the nominal concentration of 6.0 mg Ethyl Acrylate/L . A seven day diluter stock stability analysis was conducted prior to initiating the definitive study. Results indicated that ethyl acrylate was stable at a nominal concentration of 1500 mg/L for at least seven days. Fresh diluter stock was, therefore, prepared at least weekly during the study.
- Differential loading: no
- Controls: yes
- 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: in-house daphnid culture from ABC Laboratories
- Age of parental stock (mean and range, SD): < 24 hours old
- Feeding during test
- Food type: algal suspension (Selenastrum capricornutum/Ankistrodesmus falcatus)
- Amount: at least 2.0 X 108 cells/L per chamber per day
- Frequency: twice daily with 0.50 mL per test chamber of a 5.0 mg/mL suspension of daphnid supplement, which resulted in a final suspended solids concentration of 5 mg/L per chamber per day


ACCLIMATION
- Acclimation period: Since the culturing and testing parameters of temperature, dilution water hardness, and lighting were the same, no acclimation period was necessary.
- Acclimation conditions (same as test or not): yes
- Type and amount of food: no food
- Health during acclimation (any mortality observed): no mortality, no signs of stress, disease, or physical damage

Test type:

flow-through

Water media type:

freshwater

Limit test:

no

Total exposure duration:

21 d

Post exposure observation period:

no

Hardness:

144-152 mg/L as CaCO3

Test temperature:

20 - 21 °C

pH:

pH 8.3 - 8.5

Dissolved oxygen:

7.1 - 8.6 mg/L

Nominal and measured concentrations:

Nominal test concentrations: Control (0.0), 0.38, 0.75, 1.5, 3.0, and 6.0 mg/L.
Mean measured test concentrations: Control (Test concentrations were determined by HPLC analysis.

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type (delete if not applicable): open
- Material, size, headspace, fill volume: One-liter glass beakers with notched drains that were covered with 50-mesh stainless steel screens to prevent the test daphnids from escaping.
- Type of flow-through: proportional diluter with a Hamilton Micro Lab 420 syringe dispenser; flow-splitting boxes were used to thoroughly mix and divide each ethyl acrylate concentration (and control) for delivery to the test chambers
- Renewal rate of test solution (frequency/flow rate): The dilution water was delivered to each test chamber at an average rate of 4.4 mL/minute, an amount which was sufficient to replace the 1-L test volume 6.4 times in a 24-hour period.
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- Biomass loading rate: ca. 1 daphnid per 100 mL of dilution water


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: hard blended water (well water that had been demineralized by reverse osmosis)
- Total organic carbon: < 1.0 mg/L
- Particulate matter: 0.9 mg/L
- Alkalinity: 146 - 160 mg/L as CaCO3
- Conductivity: 280 - 300 μmhos/cm


OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16:8 light:dark
- Light intensity: 58-61 footcandles


EFFECT PARAMETERS MEASURED (with observation intervals if applicable):
Survival, abnormal effects, and observance of first brood of the organisms were recorded every day throughout the study. Reproductive success was
measured by counting and discarding the offspring produced in each concentration every Monday, Wednesday, and Friday for the duration of the study. At termination the length of each adult daphnid was measured from the apex of the helmet to the base of the posterior spine with a binocular dissecting microscope (Olympus VM 200M) and a calibrated eyepiece micrometer. After length measurements were complete, all of the daphnids from each individual replicate were placed in a preweighed foil pan. The daphnids were dried for approximately 48 hours at approximately 70°C. After drying, the daphnids were cooled in a desiccator before being weighed. Mean daphnid weights were determined.
Temperature, dissolved oxygen, and pH were measured on days 0, 4, 7, 14, and 21 in alternating replicates of the control and each test concentration. Water quality parameters of temperature, hardness, dissolved oxygen, pH, alkalinity, and conductivity were measured on the dilution water daily.

Reference substance (positive control):

not specified

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

0.19 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

reproduction

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

0.45 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

reproduction

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

0.5 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

immobilisation

Duration:

21 d

Dose descriptor:

other: MATC

Effect conc.:

0.29 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

reproduction

Remarks on result:

other: geometric mean of LOEC and NOEC

Details on results:

- Mortality of parent animals: Survival of Daphnia magna was shown to be significantly affected in the 0.73, 1.7, and 3.2 mg/L mean measured test concentrations, as compared to the control, after the 21-day exposure to ethyl acrylate. The mean measured concentrations of 0.19, 0.45, 0.73, 1.7, and 3.2 mg/L had mean percent survivals of 97.5, 87.5, 0, 0, and 0%, respectively. The mean percent survival for the control was 95.0.

- Time to first brood release: The 0.45 mg/L mean measured test concentration was shown to be significantly affected for time to first brood when compared to the control. The control, 0.19, and 0.45 mg/L mean measured test concentrations had mean days to first brood of 7.0, 7.3, and 8.0 days, respectively.

- Young per adult reproduction day (YAD): The mean YAD value for the mean measured concentration of 0.45 mg/L was shown to be significantly affected when compared to the control. The control, 0.19, and 0.45 mg/L mean measured test concentrations had mean YAD values of 9.03, 9.05, and 6 .81, respectively. All young produced during the study appeared normal.

- Body length and weight of parent animals: The mean length of adult Daphnia magna for the mean measured concentration of 0.45 mg/L was shown to be significantly affected when compared to the control. The control, 0.19, and 0.45 mg/L mean measured test concentrations had mean lengths of 4.04, 4.07, and 3.68 mm, respectively. The mean weight of adult Daphnia magna for the mean measured concentration of 0.45 mg/L was shown to be significantly affected when compared to the control. The control, 0.19, and 0.45 mg/L mean measured test concentrations had mean weights of 0.53, 0.55, and 0.39 mg, respectively.

Measured Concentrations of Ethyl Acrylate during the Chronic Toxicity Study with Daphnia magna:

Nominal conc. [mg/L]	Control	0.38	0.75	1.5	3.0	6.0	Diluter Stock*
Mean meas. Conc. [mg/L]	MQL	0.19	0.45	0.73	1.7	3.2	1300
Stand. Dev.	-	0.068	0.17	0.26	0.31	0.78	51
% of nominal	-	50	60	49	57	53	87

* 1500 mg/L

MQL: Minimum quantifiable limit

Percent Survival of Daphnia magna exposed to Ethyl Acrylate for 21 Days:

Nominal conc. [mg/L]	Measured conc. [mg/L]	Percent survival (mean of 4 replicates + SD)
control	control	95 ± 5.8
0.38	0.19	97.5 ± 5.0
0.75	0.45	87.5 ± 12.6
1.5	0.73	0.0 ± 0
3.0	1.7	0.0 ± 0
6.0	3.2	0.0 ± 0

Young/Adult Reproduction Days and Time for First Brood for Daphnia magna exposed to Ethyl Acrylate for 21 Days:

Nominal conc.   [mg/L]	Measured conc.   [mg/L]	Young/adult reproduction days (mean + SD)	Time to 1^st brood (mean + SD)
control	control	9.03 ± 1.30	7.00 ± 0.0
0.38	0.19	9.05 ± 1.01	7.25 ± 0.5
0.75	0.45	6.81 ± 0.62*	8.00 ± 0.82*
1.5	0.73	4.06 ± 0.60*	10.0 ± 2.71*
3.0	1.7	-	-
6.0	3.2	-	-

* significantly different from control (p < 0.05)

Adult Weights and Length Measurements for Daphnia magna exposed to Ethyl Acrylate for 21 Days:

Nominal conc.   [mg/L]	Measured conc.   [mg/L]	Adult weights [mg] (mean + SD)	Day 21 daphnid length [mm] (mean + SD)
control	control	0.53 ± 0.06	4.04 ± 0.11
0.38	0.19	0.55 ± 0.03	4.07 ± 0.06
0.75	0.45	0.39 ± 0.06*	3.68 ± 0.05*
1.5	0.73	-	-
3.0	1.7	-	-
6.0	3.2	-	-

* significantly different from control (p < 0.05)

Reference 2

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

28 Jan 2009 - 10 July 2009

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study conducted in compliance with GLP regulations

Qualifier:

according to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations:
1. From the stock solution:
Samples were taken on the following days:
Day 0 (fresh stock solution)
Day 1 (fresh stock solutions)
Day 2 (fresh and 24 hours old stock solutions)
Day 3 (fresh and 24 hours old stock solutions)
Day 4 (24 hours old stock solutions)
Day 10 (fresh stock solution)
Day 11 (24 hours old stock solution)

2. From the test solutions:
Samples were taken from the following test groups: 0.46, 1.0, 2.2 mg/L
Samples were taken on the following days:
Day 16 (fresh test solution)
Day 17 (24 hours old test solution)
Day 17 (fresh test solution)
Day 18 (24 hours old test solution)
Day 20 (fresh test solution)
Day 21 (24 hours old test solution)

- Sampling method: The concentration of the test substance was determined in each freshly prepared test solution (test vessels without daphnids) and in the 24 hour old test solutions before renewal (combined sample from test vessels with daphnids).
- Sample storage conditions before analysis: ambient temperature / samples were analyzed immediately

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: The test substance was homogenized by shaking the container before use. The stock solution (10 mg/L) was prepared by dissolving 10 mg of test substance in 1 L of test medium and stirring for approximately 5 min at 20 ± 2 °C. The test solutions were prepared by dilution of this stock solution. Before the dilution was performed, the stock solution was checked for complete dissolution of the test substance.
Fresh stock solution and test solutions were prepared and renewed daily.
- Controls: negative control (only test medium)
- Evidence of undissolved material (e.g. precipitate, surface film, etc): no. All stock solutions were visibly colorless and clear after preparation.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Strain/clone: Daphnia magna STRAUS
- Source: The clone of Daphnia magna STRAUS 1820 used was supplied by the Institut National de Recherche Chimique Appliquée, France, in 1978.
From this date on this clone was cultured and bred continuously in the Laboratory of Ecotoxicology of the Experimental Toxicology and Ecology of BASF SE in Ludwigshafen.
- Age of parental stock (mean and range, SD): no data
- Feeding during test
- Food type: Unicellular green algae (Desmodesmus subspicatus CHODAT)
- Amount: d 0-3: 0.10 mg TOC; d 4-5: 0.12 mg TOC; d 6-7: 0.14 mg TOC; d 8-21: 0.20 mg TOC/parent animal/day
- Frequency: daily


ACCLIMATION
- Acclimation period: Since the culturing and testing parameters of temperature, dilution water hardness, and lighting were the same, no acclimation period was necessary.
- Acclimation conditions (same as test): yes
- Health during acclimation (any mortality observed): no mortality, no signs of stress, disease, or physical damage


QUARANTINE (wild caught)
- Duration:
- Health/mortality:


METHOD FOR PREPARATION AND COLLECTION OF EARLY INSTARS OR OTHER LIFE STAGES:

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

21 d

Post exposure observation period:

none

Hardness:

2.20 – 3.20 mmol/L

Test temperature:

20 – 21 °C (continuous monitoring)

pH:

8.0 – 8.2

Dissolved oxygen:

8.8 - 9.1 mg/L

Nominal and measured concentrations:

- Nominal concentrations: 0, 0.1, 0.22, 0.46, 1.0, 2.2 mg/L
- Analytical concentrations: 0, 0.136 (nominal 0.46), 0.457 (nominal 1.0), 1.226 (nominal 2.2) mg/L
The mean values of n-Butyl Acrylate (n-BA) in M4-medium were found to be in the range of 9.3 – 80.0 % of the nominal concentration.

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type: closed
- Material, size, headspace, fill volume: Numbered glass flasks (nominal volume 50 mL), covered with ground glass stoppers (closed test vessels).
- Aeration: no (To assure optimal dissolved oxygen levels, the M4 medium was aerated for approximately 24 hours prior to use.)
- Renewal rate of test solution (frequency/flow rate): daily
- No. of organisms per vessel: 1 animal / test vessel
- No. of vessels per concentration (replicates):
- No. of vessels per control (replicates):
- Biomass loading rate: 0.02 animals / mL


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: A synthetic fresh water (Elendt M4) was used as media for culture and test purposes. For the composition of this M4 medium see OECD 211.
- Ca/mg ratio: about 4 : 1
- Conductivity: 550 - 650 μS/cm
- Acid capacity up to pH 4.3: 0.80 – 1.00 mmol/L
- Culture medium different from test medium: no
- Intervals of water quality measurement: once weekly



OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 hours light : 8 hours darkness
- Light intensity: About 615 - 700 lux at a wave length of 400 -750 nm (recommended values in lux units provided in ISO 10706)


EFFECT PARAMETERS MEASURED (with observation intervals if applicable):
- Daily observation of young production, mortality of the parent animals and young, and presence of aborted eggs.
- Daily observation of the appearance of the test solutions and dissolution behavior of the test substance.
- Determination of the chemical and physical parameter of the test medium prior to use: Total hardness, acid capacity, pH value and conductivity of the water after aeration and new preparation.
- Measurement of pH, oxygen and temperature in the test solutions: In the old and in the freshly prepared test solution in replicate 1 of each concentration for one interval per week.
- Measurement of hardness in the test solutions: In the freshly prepared test solution in an additional replicate of each concentration for one interval per week and in the old test solution in a combined replicate of each concentration for one interval per week.
- Measurement of temperature continuously during the whole period in a separate vessel filled with water proximal to the test vessels.
- The body length of the parent animals was determined at the end of exposure. The body length (excluding the anal spine and protruding second antennae) was determined with a microscope (Leitz Diavert) and the scale used was checked with a standardized slide.



VEHICLE CONTROL PERFORMED: no


RANGE-FINDING STUDY
- Results used to determine the conditions for the definitive study: In a preliminary test (experimental conduct in accordance with GLP but without a GLP status), after 19 days exposure to the test substance, no significant effect on reproduction was observed at 0.1 mg/L; however, a small reduction in offspring was observed at 1 mg/L.

Reference substance (positive control):

not specified

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

0.457 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

reproduction

Key result

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

0.136 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

reproduction

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

1.226 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

growth

Remarks:

: length

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

0.457 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

growth

Remarks:

: length

Details on results:

- Mortality of parent animals: no mortality related to the test substance
- Mean dead young: none
- Type and number of morphological abnormalities: none
- Type and number of behavioural abnormalities: none
- Time to first brood release: 11 days (except in the highest concentration: 12 days)
- Mean aborted eggs:
control: 0.1
0.1 mg/L: 0.0
0.22 mg/L: 0.6
0.46 mg/L: 0.8
1.0 mg/L: 1.2
2.2 mg/L: 0.3

Validity criteria:

• In the control the mortality of parent animals up to the end of the test was 0 %.

• In the control the mean number of living young per parent animal that survived the test was 95.

• No ephippia were produced in the controls.

In conclusion the test was considered to be valid.

 

 

ANALYTICAL CONCENTRATION CONTROL

 

At the start of exposure, samples for analysis were collected from the stock solution only because the analytical laboratory reported an LOQ of 4.648 mg/L. For each measurement interval, the stock solution was kept under test conditions. During course of the experiment, the analytical lab lowered the LOQ to 0.513 mg/L. Based on this information, the three highest test concentrations were analyzed over 3 daily renewal intervals starting on day 16 of the study. The final calculated LOQ reported by the analytical laboratory was 0.104 mg/L.

The analytically measured concentrations of the stock solution were lower than the expected nominal concentrations, most likely due to some volatilization of the test substance during solution preparation. However, all measured concentrations were within ± 20% of the measured mean initial concentration indicating that the test substance was stable under test conditions at the stock concentration.

The analytically determined concentrations of the test substance in the test solutions deviated by more than 20% from the nominal or mean initial measured concentrations. Therefore the time-weighted mean measured concentrations were calculated and will be used to evaluate the biological results.

 

Analytically measured concentrations of n-Butyl acrylate in the stock solutions:

 

Nominal concentration	Time period	Analytically measured concentration
		Overall mean		Mean initial
[mg/L]		[mg/L]	[%]^a	[mg/L]	[%]^b
10	Day 0	6.933	102	6.823	68
	Day 1-2
	Day 2-3
	Day 3-4
	Day 10-11

a: % of mean initial

b: % of nominal

 

Analytically measured concentrations of n-Butyl acrylate in the test solutions:

 

Nominal concentration	Time period	Analytically measured concentration
		Initial	24 h old	Time-weighted mean
[mg/L]		[mg/L]	[mg/L]	[mg/L]	[%]^a	[%]^b
0	Day 16-17	n.d.	n.d.	n.d.	-	-
	Day 17-18	n.d.	n.d.
	Day 20-21	n.d.	n.d.
0.46	Day 16-17	0.234	0.071	0.136	56	30
	Day 17-18	0.250	0.043
	Day 20-21	0.240	0.091
1	Day 16-17	0.553	0.310	0.457	79	46
	Day 17-18	0.583	0.324
	Day 20-21	0.607	0.427
2.2	Day 16-17	1.352	0.992	1.226	88	56
	Day 17-18	1.370	0.986
	Day 20-21	1.465	1.235

a: % of mean initial

b: % of nominal

n.d.: not determined

BIOLOGICAL RESULTS

 

Reproduction and Growth Summary (mean per surviving replicates after 21 days):

 

Nominal concentration	Reproduction		Growth
[mg/L]	Mean living young	% effect^b	Mean length [mm]	% effect^b
0	95.3 (9.6%^a)	-	4.0	-
0.1	100.3	-	4.1	-
0.22	92.7	-	4.1	-
0.46	94.4	-	4.1	-
1.0	84.7*	11.1*	4.1	-
2.2	68.1**	28.5**	3.6**	10**

a: Coefficient of variation for control fecundity

b: Effect relative to control (only calculated for statistically significant effects).

*: p<0.05

**: p<0.01

Validity criteria fulfilled:

yes

Description of key information

A NOEC of 0.19 mg/L was determined for long-term toxicity of Ethyl acrylate towards Daphnia magna.
NOEC (reproduction) = 0.19 mg/L (Daphnia magna, EPA OTS 797.1330, flow-through)
Data from the structurally related n-butyl acrylate:
NOEC (reproduction) = 0.136 mg/L (Daphnia magna, OECD 211, semi-static)

Data from structurally related 2-Ethylhexyl acrylate

EC10 (reproduction)= 0.85 mg/L TWM (Daphnia magna, OECD 211, semi-static)

Additional information

A 21-day chronic study with Ethyl acrylate in Daphnia magna was conducted under flow-through conditions according to EPA OTS 797.1330 (BAMM, 1997). Nominal exposure concentrations ranged from 0.38 to 6.0 mg/L. Mean measured test concentrations ranged from 0.19 to 3.2 mg/L. Effect concentrations based on measured values were as follows: EC50 was 0.5 mg/L; NOEC (reproduction) = 0.19 mg/L; LOEC (reproduction) = 0.45 mg/L and MATC (reproduction) = 0.29 mg/L.

 

A 21 -day Daphnia magna Reproduction Test sponsored by The Acrylate REACh Task Force was performed with n-Butyl acrylate under semi-static conditions in accordance with OECD TG 211 and GLP regulations (BASF SE, 2009). Nominal test concentrations were 0, 0.1, 0.22, 0.46, 1.0, and 2.2 mg/L. Since the mean values of n-Butyl Acrylate in M4-medium were found to be in the range of 9.3 – 80.0 % of the nominal concentrations, the effect concentrations were based on the time-weighted mean analytically detected concentrations. The most sensitive effect values were concerning reproduction: NOEC (reproduction) = 0.136 mg/L; LOEC (reproduction) = 0.457 mg/L. Survival of the parent or young daphnia was not effected, but the growth of the parent animals: NOEC (body length) = 0.457 mg/L; LOEC (body length) = 1.226 mg/L.

 

The effects of the long-term exposure of Daphnia magna to 2-ethylhexyl acrylate according to OECD Guideline 211 have been studied (Charles River, 2020).

The test was performed in a closed system with a semi-static renewal. Five test concentrations ranging from 5.6, 10, 18, 32 and 56% of a saturated solution prepared at a loading rate of 50 mg/L (TMW concentrations: 0.21, 0.44, 0.85, 1.4, 2.8 mg/L respectively) were employed. The effects values were related to TWM concentrations and are given as follows: 21d-EC10 (growth)= 0.85mg/L ; 21d-EC10 (reproduction)= 0.91mg/L ; 21d-EC50 (mortality)= 1.6 mg/L