Sodium acrylate

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

20 Dec 1995 - 21 May 1996

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

GLP-guideline study with analytical monitoring

Qualifier:

according to guideline

Guideline:

EPA OTS 797.1930 (Mysid Acute Toxicity Test)

GLP compliance:

yes

Analytical monitoring:

yes

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
One stock solution for each test concentration was prepared. Acrylic acid was dissolved in reverse osmosis water at a concentration of 200 mg/L. Aliquots were diluted with reverse osmosis water to prepare stock solutions at concentrations of 25.9, 43.2, 72 and 120 mg/L. The stock solutions were mixed with saltwater (at a rate of 125 mL/minute) to achieve the desired test concentration.

Test organisms (species):

Americamysis bahia (previous name: Mysidopsis bahia)

Details on test organisms:

TEST ORGANISM
- Common name: saltwater mysid
- Source: Wildlife International Ltd., Easton, Maryland, USA
- Age at study initiation: juvenile
- Feeding during test: yes, to prevent cannibalism
- Food type: live brine shrimp nauplii (Artemia sp.)
- Frequency: twice daily

HOLDING
- Holding period: 14 d
- Holding conditions: water temperature 24.5 - 25.1 °C, pH 8.1 - 8.2, salinity 20 - 22 ‰, dissolved oxygen 7.0 - 7.5 mg/L
- Health during acclimation: The adults show no signs of disease or stress

Test type:

flow-through

Water media type:

saltwater

Limit test:

no

Total exposure duration:

96 h

Test temperature:

25 ± 2 °C

pH:

4.4 - 8.3

Dissolved oxygen:

7.0 - 7.5 mg/L

Salinity:

20 - 22 ‰

Nominal and measured concentrations:

Nominal test concentrations: control, 26, 43, 72, 120, 200 mg/L
Mean measured test concentrations: 30, 48, 80, 126 and 239 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Material, total volume, depth of water: glass beakers with nylon screen-covered holes on opposite sides of each beaker, 300 mL, 7.2 cm
- Type of flow-through: peristaltic diluter
- Renewal rate of test solution (frequency/flow rate): ca. 14 volume additions of test water every 24 hours
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Natural seawater (Indian River Inlet, Delaware, USA) diluted with well water to a salinity of ca. 20 ‰. Seawater was passed through a sand filter (ca. 25 µm). The mixture of sea and well water was aerated. Before delivering to the test system the water was filtered again to remove microorganisms and particles.
- Intervals of water quality measurement:
- Temperature was measured in each test chamber at the beginning and the end of the test and continously in one negative control replicate
- Dissolved oxygen, pH, salinity were measured at test initation, at 48 h, at test termination

OTHER TEST CONDITIONS
- Photoperiod:16 hours light : 8 hours darkness with a 30-minute transition period
- Light intensity: 295 - 308 Lux

EFFECT PARAMETERS MEASURED: mortality and clinical signs after 24, 48, 72, 96 hours

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

97 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: 95 % CL 80 - 126 mg/L

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

48 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

other: mortality, clinical observation

Duration:

96 h

Dose descriptor:

LC0

Effect conc.:

48 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality

Details on results:

EC 50 (24h, 48h, 72h): 166, 105, 103 mg/L
Recovery rates (0 h): 102 - 122 %
Recovery rates (48, 96 h): 104 - 134 %

Validity criteria fulfilled:

yes

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

06 Apr 1989 - 08 Apr 1989 (experimental)

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

GLP-guideline study with analytical monitoring

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes

Analytical monitoring:

yes

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
Final concentration of the stock solution: 12000 mg/L

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Source: in-house daphnid culture which has been maintained by ABC since 1977. The primary culture was obtained from the Columbia National Fisheries Research Laboratory (CNFRL), Columbia, Missouri, USA.
- Age at study initiatio: < 24 hours

HOLDING
- Holding conditions: Temperature 20 ± 2 °C
- Photoperiod: 16 hours daylight with 30 min dawn and dusk transition periods
- Frequency: 50 - 70 footcandles
- Food type: suspension of algae (Selenastrum capricornutum) supplemented with Tetramin/cereal. leaves/yeast suspension

Test type:

flow-through

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

174 - 178 mg/L as CaC02

Test temperature:

19 °C

pH:

6.7 - 7.7

Dissolved oxygen:

7.9 - 8.0 mg/L

Nominal and measured concentrations:

Nominal test concentrations: control, 7.2, 14, 30, 60, 120 mg/L
Mean measured concentrations: < 0.1, 7.9, 13, 23, 50, 110 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Material, total volume, fill volume: glass beakres with notched overflows, 1 L, 1 L
- Type of flow-through: proportional diluter
- Renewal rate of test solution: 4.2 mL/chamber/min; 1-liter test volume ca. 6.0 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: 1 daphnid/100 mL

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: a blend of reverse osmosis water and ABC well water
- Total organic carbon: < 1.0 ppm
- Suspended Solids: 0.5 ppm
- Chlorine: < 0.05 ppm
- Alkalinity: 204 - 206 mg/L as CaCO3
- Conductivity: 320 - 340 µMHOS/cm
- Intervals of water quality measurement: Dissolved oxygen and pH were measured in each test concentration at 0 and 48 hours of testing

OTHER TEST CONDITIONS
- Photoperiod: 16 hours daylight and 8 hours darkness with 30 min dawn and dusk transition periods
- Light intensity: 50 - 70 ft. c. intensity

EFFECT PARAMETERS MEASURED: immobilization and other abnormal effects such as surfacing, erratic movement, daphnids laying on the bottom after 4, 24, 48 hours

TEST CONCENTRATIONS
- Range finding study: 2 range finding study were performed
- First test: 48-hour static toxicity test
- Test concentrations: 0.01, 0.1, 1.0 and 10 mg/L
- Results used to determine the conditions for the definitive study: no mortality in any of the levels, but abnormal behavioral effects of the daphnids in the top three levels
- Second test: 48-hour flow-through toxicity test
- Test concentrations: 6.0, 12, 25, 50 and 100 mg/L
- Results used to determine the conditions for the definitive study: no mortality after 48 hours, but showed abnormal behavioral effects at the 100 mg/L test level

Reference substance (positive control):

not specified

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

95 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95 % CL 83 - 110 mg/L

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

23 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

other: mortality, abnormal effects

Validity criteria fulfilled:

yes

Description of key information

Sodium acrylate is acute harmful to aquatic invertebrates. Based on data for the structural analogue acrylic acid, the EC 50 was 95 mg/L

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

95 mg/L

Marine water invertebrates

Marine water invertebrates

Dose descriptor:

EC50

Effect concentration:

97 mg/L

Additional information

No experimental data on the test substance is available. Sodium acrylate (NaA) is dissociating fast in aqueous media (Henderson – Hasselbach calculation). Therefore, the evaluation of the endpoint short term toxicity to aquatic invertebrates is based on a weight of evidence approach using the data of the structural analogue acrylic acid (AA) (CAS 79-10-7) (for WoE information, see chapter 13.2).

An experimental study according to GLP regulations and the guideline EPA OTS 797.1300 (Aquatic Invertebrates Acute Toxicity Test, Freshwater Daphnids) with AA was conducted (BAMM, 1990). Daphnia magna was exposed to the mean measured concentrations of < 0.1 (control), 7.9, 13, 23, 50 and 110 mg/L in a flow- through system over 48 h. The EC50 (48 h) was 95 mg/L based on the measured concentrations with mobility as basis for the effect. The study was supported by analytical monitoring and no deviations from the guideline were reported. Therefore, the study was rated as highly reliable (Klimisch score 1).  A second experimental study with Daphnia magna in freshwater was conducted according to GLP regulations and the guideline EU Method C.2 (Acute Toxicity for Daphnia) (Huels, 1995).The test species was exposed to the nominal concentrations of 12, 20, 35, 60, 100 mg/L and a control in a static system over 48 h. The concentrations were measured in a separate test vessel and the recovery was more than 80 % of the nominal values. The EC50 (48h) was 47 mg/L bases on mobility and nominal concentrations. Due to the analytical measurements in separate test vessels and the derivation of the effect values from nominal concentrations the study was rated with Klimisch score 2. The results were in the same range as those of the other invertebrate freshwater study (BAMM, 1990) and is therefore reliable and adequate to support other information.

To assess the acute toxicity of AA to saltwater species, an experimental study according to GLP regulations and the guideline EPA OTS 797.1930 (Mysid Acute Toxicity Test) was conducted (BAMM, 1996) Americamyiss bahia was exposed to a control and the mean measured concentrations of 30, 48, 80, 126 and 239 mg/L  for 96 h in a flow-through system. The study was rated as highly reliable (Klimisch score 2). The LC50 after 96 h was measured as 97 mg/L  and in the same range as for the freshwater species Daphnia magna (LC50 = 95 mg/L, BAMM 1990).  By choosing these values to assess the acute toxicity of NaA to invertebrates in freshwater and saltwater a worst-case assumption is made.