Fatty acids, rape-oil, mixed esters with 1,4:3,6-dianhydro-d-glucitol, sorbitan and sorbitol

Endpoint summary

Additional information

There are no data available investigating the aquatic toxicity ofFatty acids, rape-oil, mixed esters with 1,4:3,6-dianhydro-d-glucitol, sorbitan and sorbitol (CAS 93334-10-2). In order to fulfil the standard information requirements set out in Annex VII, 9.2.1.1, in accordance with Annex XI, 1.5, of Regulation (EC) No 1907/2006, read-across from structurally related source substances was conducted.

In accordance with Article 13 (1) of Regulation (EC) No 1907/2006, "information on intrinsic properties of substances may be generated by means other than tests, provided that the conditions set out in Annex XI are met.” In particular for human toxicity, information shall be generated whenever possible by means other than vertebrate animal tests, which includes the use of information from structurally related substances (grouping or read-across).

Having regard to the general rules for grouping of substances and read-across approach laid down in Annex XI, Item 1.5, of Regulation (EC) No 1907/2006 whereby substances may be predicted as similar provided that their physicochemical, toxicological and ecotoxicological properties are likely to be similar or follow a regular pattern as a result of structural similarity.

Based on the specification the target substance Fatty acids, rape-oil, mixed esters with 1,4:3,6-dianhydro-d-glucitol, sorbitan and sorbitol is characterized by the alcohol components sorbitol, sorbitan and 1,4:3,6-dianhydro-d-glucitol esterified as mono (mainly), -di- or tri-ester with mainly fatty acids of C18 and C18 unsaturated. The source substances are specified as followed:

-         Sorbitan stearate (CAS 1338-41-6) is characterized as a mono-, di- and tri-ester of sorbitan with C16-C18 fatty acids.

-         Sorbitan oleate (CAS 1338-43-8) consists of sorbitan and C18 unsaturated fatty acid.

-         Sorbitan, (Z)-9-octadecenoate (2:3) (CAS 8007-43-0) is an ester (mono, di and tri) of sorbitan, sorbitol and 1,4:3,6-dianhydro-d-glucitol with C18 unsaturated fatty acid.

-         Sorbitan laurate (CAS 1338-39-2) is characterized as a mono-, di- and tri-ester of sorbitol with mainly C12 fatty acids.

-         Sorbitane isooctadecanoate (CAS 71902-01-7) is an ester (mono, di and tri) of sorbitan and 1,4:3,6-dianhydro-d-glucitol with C18 branched fatty acid.

A detailed analogue approach justification is provided in the technical dossier (see IUCLID Section 13).

Short-term aquatic toxicity data are available for all trophic levels from suitable source substances. Long-term data are available for aquatic invertebrates and algae. Based on the experimental data, the toxicity to aquatic organisms is low. Additionally, the exposure concentrations of aquatic organisms are expected to be very low, due to the efficient removal in sewage treatment plants since the substance is readily biodegradable. The substance is also poorly soluble in water and has a potential for adsorption, which further contributes to the removal from waste water.

Short term toxicity to aquatic invertebrates

The assessment of short-term toxicity to aquatic invertebrates is based on reliable guideline studies with freshwater and marine species. No effects were observed for the poorly soluble substances Sorbitan strearate (CAS 1338-41-6) and Sorbitan oleate (CAS 1338-43-8). For the source substance Sorbitan, (Z)-9-octadecenoate (2:3) (CAS 8007-43-0) immobilization (LL50) was observed at a loading rate of 7756 mg/L. As this effect is far above the water solubility limit, undissolved material may still have been present at such high loading rates, even though these tests were performed with water accommodated fractions. The immobilisation could thus be caused by physical rather than systemic effects. It can be concluded that the target substance is of low acute toxicity to aquatic invertebrates. The source substances are suitable to assess the chronic toxicity of the target substance as explained above.

Long term toxicity to aquatic invertebrates

The assessment of long-term toxicity to aquatic invertebrates is based on reliable guideline studies conducted with Daphnia magna. No effect on reproduction of the test organisms was observed in any of these studies. The source substances Sorbitan stearate (CAS 1338-41-6) and Sorbitan, (Z)-9-octadecenoate (2:3) (CAS 8007-43-0) are suitable to assess the chronic toxicity of the target substance as explained above.

Toxicity to algae

The assessment of toxicity to algae is based on reliable guideline studies with freshwater and marine species. No effects were observed in the study carried out with Sorbitan stearate (CAS 1338-41-6). With Sorbitan, (Z)-9-octadecenoate (2:3) (CAS 8007-43-0) effects were observed, and an EL50 (72 h) of 1916 mg/L is reported. However, the test concentrations were far above the solubility limit of the substance. Although the test was performed as water accommodated fractions (WAF), the presence of undissolved material cannot be excluded. Thus this effect was not considered to be related to systemic effects but to physical effects. It can be concluded that the target substance is of low acute toxicity to aquatic algae. The source substances are suitable to assess the toxicity of the target substance as explained above.

Toxicity to microorganisms                                                              

The assessment of toxicity to activated sludge microorganisms is based on one standard microorganism study (OECD 209) and a toxicity control from a ready biodegradation study (OECD 301B). In the OECD 209 test conducted with Sorbitan laurate (CAS 1338-39-2) no effect on the respiration rate of activated sludge was observed. The toxicity control available from a biodegradation study for Sorbitan isooctadecanoate (CAS 71902-01-7) showed no toxicity to microorganisms either. It can be concluded that no effects on the STP microorganism community and the subsequent degradation process in sewage treatment plants is expected. The source substances are suitable to assess the toxicity of the target substance as explained above.

General conclusion

Finally, the data available on aquatic toxicity show a clear, consistent pattern of low toxicity to aquatic organisms with no effects up to the limit of water solubility. The available studies are suitable to cover the target substance. Data gaps were covered by read-across, in accordance to Regulation (EC) No. 1907/2006 Annex XI, 1.5 Grouping of substances and read-across. Read-across substances were chosen based on the similarity of the molecular structure and of physico-chemical properties. A detailed justification for the grouping of chemicals and read-across is provided in the technical dossier (see IUCLID Section 13).