Poly(oxy-1,2-ethanediyl), α-(carboxymethyl)-ω-hydroxy-, C16-18 (even numbered) and C18-unsatd. alkyl ethers

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:

28 June 1995 to 30 June 1995

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)

Version / remarks:

1984

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

Samples of the test solutions were taken at 0 and 48 hours. Chemical analysis was also performed on the aqueous stock solutions used to prepare the test series at -24, 0 and 24 hours.

Sodiurn chloride (30% w/v) was added to each solution and dissolved by shaking. After acidification with glacial acetic acid (1 drop per 500 mL), the solutions were extracted with three portions (3 x 50 mL) of dichloromethane, filtered through anhydrous sodium sulphate and evaporated to dryness. The residue was silylated with N-methyl-Ntrimethylsilyl-trifluoroacetamide (MSTFA; 0.9 mL) in trifluoroacetic acid (0.1 mL). The
resulting solution was diluted with acetonitrile (previously dried over anhydrous sodium sulphate) to give a final test material concentration of 450 mg/L or 1800 mg/L.

Vehicle:

not specified

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
Amounts of test material (82.5, 150, 270 and 450 mg) were dispersed in deionised reverse osmosis water and the volume adjusted to 100 ml to give aqueous stock solutions of 82.5, 150, 270 and 450 mg/100 mL. Dilutions were made from these stock solutions to prepare further stock solutions of 4.5, 8.25, 15, 27 and 45 mg/100 mL. These stock solutions were freshly prepared at -24, 0 and 24 hours prior to dosing by dynamic, continuous flow apparatus to give the test concentrations 0.060, 0.11, 0.20, 0.36, 0.6, 1.1, 2.0, 3.6 and 6.0 mg/L. The stock solutions were adjusted to pH 7.5.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Strain/clone: STRAUS
- Source: Institut National Recherche Chimique Appliquée (I.R.CH.A).
- Feeding during test: no feeding during exposure

ACCLIMATION
- Acclimation conditions (same as test or not): same
- Type and amount of food: daily with a suspension of mixed algae (predominantly Chlorella spp.).
- Health during acclimation (any mortality observed): Culture conditions ensured that reproduction was by parthenogenesis.

Test type:

flow-through

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

110 mg/L as CaCO3

Test temperature:

21ºC

pH:

8.1

Dissolved oxygen:

8.4 mg O2/L

Nominal and measured concentrations:

First range-fiding study concentration: 0.10, 1.0, 10, 20, 40 and 100 mg/L.
Second range-finding: 1.0, 2.0, 4.0, 6.0, 8.0 and 10 mg/L.
Definitive study: 0.060, 0.11, 0.20, 0.36, 0.60, 1.1, 2.0, 3.6 and 6.0 mg/L.

Details on test conditions:

TEST SYSTEM
- Test vessel: 250 mL glass vessels containing approximately 250 mL of test solution, covered to reduce evaporation
- Aeration: no
- Type of flow-through (e.g. peristaltic or proportional diluter): The diluent supply was pumped at a rate of 10 ml/min by a Watson Marlow peristaltic pump and the aqueous stock solutions dosed by a Harvard '22' syringe pump at a rate of 0.80 ml/hour. The dosing apparatus was set up approximately 24 hours prior to the study start to allow equilibration of the test concentrations.
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2


OTHER TEST CONDITIONS
- Adjustment of pH: yes
- Photoperiod: 16 h light/8 h dark


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
immobilisation or adverse reactions were recorded at 24 and 48 hours after the start of exposure


RANGE-FINDING STUDY
- Results used to determine the conditions for the definitive study:
The results showed no immobilisation at the test concentration of 1.0 mg/L. However, immobilisation was observed at 2.0, 4.0 and 6.0 mg/L. Based on this information test concentrations of 0.060, 0.11, 0.20, 0.36, 0.60, 1.1, 2.0, 3.6 and 6.0 mg/L were selected for the definitive study.

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

3.1 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

act. ingr.

Basis for effect:

mobility

Remarks on result:

other: 95% c.i. 2.7 - 3.7 mg/L

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

1.6 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

act. ingr.

Basis for effect:

mobility

Remarks on result:

other: 95% c.i. 1.2-2.0 mg/L

Details on results:

Behavioural observation: there were no adverse reactions to exposure

Immobilization data based on nominal concentrations

Time (h)	EC50 (mg/L)	95% Confidence Limits (mg/L)
24	3.6	3.1 -4.3
48	1.6	1.3 -1.9

Validity criteria fulfilled:

yes

Conclusions:

The acute toxicity of the test substance to the freshwater invertebrate Daphnia magna has been investigated and gave a 48-hour EC50 value of 1.6 mg/L with 95% confidence limits of 1.3-1.9 mg/L.

Executive summary:

The study was performed to assess the acute toxicity of the test material to Daphnia magna. The method followed the OECD Guideline 202. Following preliminary range-finding studies, twenty daphnids (2 replicates of 10 animals) were exposed to an aqueous dispersion of the test material at concentrations of 0.060, 0.11, 0.20, 0.36, 0.60, 1.1, 2.0, 3.6 and 6.0 mg/L for 48 hours under dynamic, continuous flow test conditions. The number of immobilised Daphnia were recorded after 24 and 48 hours. The 48-hour EC50 for the test material to Daphnia magna based on mean measured test concentrations was 1.6 mg/L was 95% confidence limits of 1.2 -2.0 mg/L. The No Observed Concentration at 48 hours was 0.60 mg/L

Description of key information

48 h EC50 = 1.6 mg/L (95% confidence limits of 1.2 -2.0 mg/L) (Daphnia magna) (RL1, GLP; OECD TG 202)

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

1.6 mg/L

Additional information

The 48-hr-acute toxicity of Polyoxyethylene(1 to 2.5) oleyl ether carboxylic acid to Daphnia magna was studied under semi-static conditions according to OECD Guideline 202 (1984). Daphnids were exposed to control and test chemical at nominal concentrations of 0.060, 0.11, 0.20, 0.36, 0.60, 1.1, 2.0, 3.6 and 6.0 mg/L for 48 hours under dynamic, continuous flow test conditions.

The number of immobilised Daphnia were recorded after 24 and 48 hours. The 48-hour EC50 for the test material to Daphnia magna based on mean measured test concentrations was 1.6 mg/L with 95% confidence limits of 1.2 -2.0 mg/L. The No Observed Concentration at 48 hours was 0.60 mg/L