Triglycerides, C16 and C18 (unsaturated)

Ecotoxicological Summary

Conclusion on classification

 No data are available for aquatic toxicity for Triglycerides, C16 and C18 (unsaturated). Read across from glyceryl trioleate is used to complete the ‘Short-term toxicity to aquatic invertebrates’ and ‘Toxicity to aquatic algae and cyanobacteria’ endpoints. For the read across substance, glyceryl trioleate, the 48-hour EL50 value for immobilisation of Daphnia magna was determined to be >100 mg/L loading rate WAF. In an algal growth inhibition study with glyceryl trioleate, the 72 hr EL50 value based growth rate was > 100 mg/L loading rate WAF. Therefore, Triglycerides, C16 and C18 (unsaturated) is not expected to be acutely toxic in the aquatic environment and does not need to be classified for acute aquatic toxicity.

 

Chronic toxicity data are only available for algae for the read across substance. After 72 hours no effects on the growth of algae were observed at 100 mg/L loading rate WAF, which indicates that the substance is not toxic to algae after long-term exposure.

 

As chronic toxicity data for the read across substance are only available for one trophic level, acute toxicity data together with environmental fate data are also assessed. Biodegradation data are not available for Triglycerides, C16 and C18 (unsaturated) but data have been read across from fatty acids with the same chain lengths. The fatty acids stearic acid and palmitic acid are readily biodegradable. No bioaccumulation data is available for Triglycerides, C16 and C18 (unsaturated). The partition coefficient (log Kow) of the test item was determined to be >6.2 by the HPLC method. Moreover, QSAR predictions using the KOWWIN v1.68 model (US EPA 2012) for the C16 and C18 structures present in the target substance estimate log Kow values of 22.46 and 25.41, respectively. According to ECHA guidelines (ECHA 2017) a partition coefficient value (log Kow) greater than 3 indicates that a substance has a significant potential for bioaccumulation. However, it is considered that for certain types of substances, the log Kow value may not be suitable for prediction of bioaccumulation potential as there are a number of factors which may affect bioaccumulation, such as size of molecule, biodegradation rate in the aquatic environment, metabolism in organisms and bioaccumulation potential of the metabolites. Log Kow values greater than 8 should be treated with caution as usually the methods do not allow for reliable measurement. In addition, very high log Kow values (>10), indicate that the bioaccumulation potential of substance is reduced. On this basis, Triglycerides, C16 and C18 (unsaturated) would be unlikely to bioaccumulate in organisms. The short-term EL50 values for the read across substance for Daphnia and algae (growth rate inhibition) are > 100 mg/L loading rate WAF, therefore it can be concluded that Triglycerides, C16 and C18 (unsaturated) is not hazardous to the aquatic environment with long lasting effects and no classification for chronic toxicity is required.