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

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Endpoint:

toxicity to microorganisms, other

Type of information:

experimental study

Adequacy of study:

key study

Study period:

02 July 2015 to 05 August 2015

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

other: OECD 301B and EU C.4-C

Version / remarks:

Toxicity test performed as part of a ready biodegradability CO2 evolution test performed according to OECD 301B and EU C.4-C.

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 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

Test organisms (species):

activated sludge of a predominantly domestic sewage

Details on inoculum:

Activated sludge from a biologic sewage treatment plant treating mostly domestic sewage was used. The sludge was taken from the activation basin of the ESN (Stadtentsorgung Neustadt) sewage treatment plant, Im Altenschemel, NW-Lachen-Speyerdorf on 03 July 2015.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

28 d

Test temperature:

Test temperature was 20.0 to 23.1 °C.

Nominal and measured concentrations:

ZWA 5496/100 was tested using a nominal concentration of 20 mg organic carbon/L (corresponding to 29 mg ZWA 5496/100/L) in test medium following OECD 301B and EU-Method C.4-C.

Key result

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

29 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: inhibition of CO2 evolution

Validity criteria fulfilled:

yes

Conclusions:

The test substance is considered as not toxic towards the inoculum at a concentration of 29 mg/L. Degradation in the toxicity flask was 57% after 14 days. The guideline indicates that the test item can be considered as toxic towards the inoculum if degradation in the toxicity flask is below 25% after 14 days.

Description of key information

The key study was a toxicity control conducted as part of a CO₂ evolution test in accordance with OECD Guideline 301B. The substance was shown to be non-inhibitory toward the inoculum at a concentration of 29 mg/L. Degradation in the toxicity flask was 57% after 14 days.

Key value for chemical safety assessment

EC10 or NOEC for microorganisms:

29 mg/L