Reaction product of D-Glucopyranoside, methyl; esterified with oleic acid, methyl ester

Endpoint summary

Description of key information

Toxicity to fish

The acute toxicity of the test substance towards towards rainbow trout (Oncorhynchus mykiss) was determined according to OECD Guideline 203 and EU Method C.1 in compliance with GLP (Sacker, 2015(a)).

In accordance with the recommendations of REACH, the test was conducted according to the threshold approach recommended by ECHA. Using this approach the lowest EL₅₀value from either the Algal Growth Inhibition study or Acute Toxicity to Daphnia magna study is set as the threshold loading rate and a "Limit test" is conducted at this threshold loading rate. If no mortalities are observed this indicates that fish are not the most sensitive species and that the LL₅₀is greater than the threshold loading rate.

Therefore seven fish were exposed to a Water Accommodated Fraction (WAF) of the test material, at a single nominal loading rate of 100 mg/L for a period of 96 hours at a temperature of approximately 14°C to 15°C under semi-static test conditions. The number of mortalities and any sub-lethal effects of exposure in each test and control vessel were determined 3 and 6 hours after the start of exposure and then daily throughout the test until termination after 96 hours.

The 96-Hour LL₅₀(Lethal Loading rate) based on nominal loading rates was greater than 100 mg/L loading rate WAF and correspondingly the No Observed Effect Loading rate was 100 mg/L loading rate WAF. It was considered unnecessary and unrealistic to test at loading rates in excess of 100 mg/L.

Toxicity to aquatic invertebrates

In the key study, the toxicity of the test item under static conditions was investigated by Sacker, 2015(b) in accordance with OECD Guideline 202 under GLP compliance. Following a preliminary range-finding test, twenty daphnids (four replicates of five animals) were exposed to a Water Accommodated Fraction (WAF) of the test item, at a single nominal loading rate of 100 mg/L for 48 hours at a temperature of 21 °C to 22 °C under static test conditions. Immobilisation and any adverse reactions to exposure were recorded after 24 and 48 hours. The EL₅₀ (48h) for the test material to Daphnia magna based on nominal loading rates was greater than 100 mg/L loading rate WAF and correspondingly the No Observed Effect Loading rate was 100 mg/L loading rate WAF.

Toxicity to aquatic algae

A study (Vryenhoef, 2016) was performed to assess the effect of the test item on the growth of the green algae Pseudokirchneriella subcapitata. The method followed was designed to be compatible with the OECD Guideline 201 referenced as EU Method C.3.

Following a preliminary range-finding test, Pseudokirchneriella subcapitata was exposed to a Water Accommodated Fraction (WAF) of the test item, at a single nominal loading rate of 100 mg/L (six replicate flasks) for 72 hours, under constant illumination and shaking at a temperature of 24 ± 1 °C.

Analysis of the 100 mg/L loading rate WAF test preparations at 0 and 72 hours showed measured test concentrations of less than the limit of quantification (LOQ) of the analytical method which was determined to be 0.19 mg/L. This does not infer that no test item was in solution, just that any dissolved test item was at a concentration of less than the LOQ.

Exposure of Pseudokirchneriella subcapitata to the test item gave ErL₅₀ values and EbL₅₀ of greater than 100 mg/L loading rate WAF. The No Observed Effect Loading Rate referring to growth rate and yield (biomass) was 100 mg/L loading rate WAF.

No effects (size differences, unusual cell shapes) were noted during the test.

Toxicity to aquatic microorganisms

The test item was used in an experiment according to OECD Guideline 209 by Best, 2015 (A).

Activated sewage sludge was exposed to an aqueous dispersion of the test item at concentrations of 10, 100 and 1000 mg/L (3 replicates of the 1000 mg/L test concentration) for a period of 3 hours at a temperature of approximately 19 °C with the addition of a synthetic sewage as a respiratory substrate.

The rate of respiration was determined after 3 hours contact time and compared to data for the control and a reference item, 3,5-dichlorophenol.

The effect of the test item on the respiration of activated sewage sludge gave a 3-Hour EC₅₀value of greater than 1000 mg/L. The No Observed Effect Concentration (NOEC) after 3 hours exposure was 1000 mg/L.

Additional information

General considerations

Ecotoxicological investigations were performed for the substance itself via experimental data concerning toxicity towards fish, aquatic invertebrates (daphnia), algae and bacteria.

Based on the intrinsic properties of the test item, Water Accommodated Fractions (WAFs) were prepared for testing (except for toxicitx toward bacteria). This procedure is in accordance with the OECD Guidance document on aquatic toxicity testing of difficult substances and mixtures (Series on testing and assessment - Number 23; OECD, 2000). The term WAF is applied to aqueous media containing only the fraction of multi-component substances that is dissolved and / or present as a stable dispersion or emulsion. These fractions are prepared individually and not by serial dilution of a single stock WAF. As the term indicates, only a fraction of the total mass of multi-component substances responsible for the composition may be present in the WAF. The "loading rate" is the mass to volume ratio of the mixture to medium used in the preparation. The obtained LL₅₀/ EL₅₀ values are comparable to LC₅₀/ EC₅₀ values, as well as the NOELR (No Observable Effect Loading Rate) to NOEC (No Observable Effect Concentration).