Fatty acids, tall-oil, reaction products with linseed oil, maleic anhydride and methanol

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 August 2015 to 20 August 2015

Reliability:

1 (reliable without restriction)

Reason / purpose for cross-reference:

other: Basis for representation of test solution concentrations.

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

The test substance is listed as ZWA 5496/100. The test substance, a brown liquid, is the reaction product of maleic anhydride, disproportioned tall oil fatty acid, linseed oil and methanol. The test substance was obtained from Allnex Belgium and was stored at room temperature (20 ± 5°C) and kept away from light.

Analytical monitoring:

yes

Vehicle:

no

Details on test solutions:

The test substance is listed as ZWA 5496/100. The test substance is the reaction product of maleic anhydride, disproportioned tall oil fatty acid, linseed oil and methanol. The test substance was obtained from Allnex Belgium and was stored at room temperature (20 ± 5°C).

Test organisms (species):

Daphnia magna

Details on test organisms:

The test species, Daphnia magna STRAUS, were from the in-house laboratory breeding culture since 27 September 2007. Young female daphnids selected for the test were an age of <24 h.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

The hardness of the deionised dilution water was 2.502 mmol/L or 250 mg CaCO3/L.

Test temperature:

The temperature of the test medium was 19.4°C to 20.7 °C and complied with the requirements of the protocol (18-22°C, constant within 2°C).

pH:

The pH during the test measured between 7.1 and 7.7 and complied with the requirements of the protocol (6.0-8.5, not varying by more than 1.5 unit).

Dissolved oxygen:

The oxygen concentrations measured during the test were between 8.5 and 8.7 mg/L and complied with the requirements of the protocol (≥3 mg/L at the end of the test).

Salinity:

No information provided.

Conductivity:

No information provided.

Nominal and measured concentrations:

The experimental test was performed with one nominal test substance concentration of 100 mg/L; the test solution was prepared using the water-accommodated fraction. The decision to test one nominal concentration was based on the results of the algae study (Muckle, 2015). Analytical monitoring was conducted on the basis of dissolved organic carbon (DOC). Due to a technical failure, the DOC was not determined in the treatment group at the end of the test. The failure was described as "uncritical" because, during a comparable study with algae, the measured DOC and in agreement at the same nominal concentration was in a similar range and stable under test conditions. In the algae study, the presence of the dissolved test item was only confirmed in the higher concentration treatment groups (32 - 100 mg/L); in the lower concentration treatment groups. The DOC in the test solutions was in the same range as the controls. Therefore, no calculation of the test item concentration based on the organic carbon contents of the test item and DOC measurement was performed. Therefore, in agreement with the evaluation of the algae study, the determination of results was based on the nominal concentrations, in agreement with OECD guidance document no. 23. OECD guidance document no. 23 states “For tests with chemicals that cannot be quantified by analytical methods at the concentrations causing effects, the effect concentration can be expressed based on the nominal concentrations”.

Details on test conditions:

One valid experiment was performed. The study was performed using one nominal test substance concentration containing 100 mg/L. For the test concentration, 20 Daphnia were exposed to the test item for 48 hours in a static test system. After 24 and 48 hour, the immobilised Daphnia were counted. None of the animals were immobilised in the control and in the treatment. Potassium dichromate K2Cr2O7 was used as a positive control in the reference study.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate K2Cr2O7 (CAS No. 7778-50-9) was used as a positive control in the reference study.

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

LOEC

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

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:

One valid experiment was performed. The study was performed using one nominal concentration containing 100 mg/L. For the test concentration, 20 Daphnia were exposed to the test item for 48 hours in a static test system. After 24 and 48 hour, the immobilised Daphnia were counted. None of the animals were immobilised in the control and in the treatment. Potassium dichromate K2Cr2O7 was used as a positive control in the reference study.

Results with reference substance (positive control):

The 24 h EC50 was 1.6 mg/L within the required range of 0.6 mg/L and 1.7 mg/L. For the estimation of the EC50 of the positive control, the fit showed sufficient statistical correspondence of the data with the dose-response equation.

Validity criteria fulfilled:

yes

Conclusions:

The test substance did not induce acute immobilisation of Daphnia magna at a nominal concentration of 100 mg/L after 48 h of exposure. The 48 h NOEC was ≥ 100 mg/L based on one nominal concentration. The 48 h EC50 was ≥ 100 mg/L based on one nominal test substance concentration of 100 mg/L.

Description of key information

The key study was a static acute invertebrate toxicity test on the effects of the substance on the freshwater invertebrate Daphnia magna following OECD Guideline 202. No toxicity of the substance to the daphnids was observed; the 48-h NOEC was reported as ≥ 100 mg/L (based on the water-accommodated fraction); the 48-h LOEC and 48-h EC50 were each reported as > 100 mg/L (based on the water-accommodated fraction).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

100 mg/L