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Ecotoxicological information

Toxicity to microorganisms

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Description of key information

EC10 (3 h) of > 1000 mg/L for activated sludge microorganisms (OECD 209).

Key value for chemical safety assessment

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Since no studies investigating the toxicity to aquatic algae of fatty acids, coco, di-and triesters with trimethylolpropane (CAS 85566-29-6) are available for this endpoint, in accordance to Regulation (EC) No. 1907/2006 Annex XI, 1.5 a read across to the structurally related category members fatty acids, C8-10 (even numbered), di-and triesters with propylidynetrimethanol (CAS 11138-60-6) and Fatty acids, C8-10(even), C14-18(even) and C16-18(even)-unsatd., triesters with trimethylolpropane (former CAS 85186-89-6) was conducted. The read-across substances cover the lower- (CAS 11138-60-6) and the upper-end (former CAS 85186-89-6) of the substance and thus allow for interpolation to fatty acids, coco, di-and triesters with trimethylolpropane (CAS 85566-29-6). This read-across is justified in detail in the overall summary (IUCLID Section 6.1) and within the category justification in IUCLID Section 13. In this case of read-across, the best suited (highest degree of structural similarity, nearest physico-chemical properties) read-across substance was used for the assessment. Nevertheless, as it can be seen in the data matrix of the category justification in section 13 and the overall summary (IUCLID section 6.1), all reliable data in the category support the hazard assessment of each category member by showing a consistent pattern of results.

The first study with the read-across substance fatty acids, C8-10 (even numbered), di-and triesters with propylidynetrimethanol (CAS 11138-60-6) was performed according to OECD 209 (Kuttler, 1998). Incubation resulted in an increase of about 43% of respiration rate at the nominal tested concentration of 10000 mg/L compared to the control. No inhibition of respiration rate of activated sludge microorganisms was observed. Therefore the EC50 and EC10 (3 h) can be stated as > 10000 mg/L (nominal). Furthermore, the biodegradation tests exhibit the readily biodegradability of the test substance. Thus, a disturbance in the biodegradation process of a sewage treatment plant is not anticipated.

The second study with the read-across substance Fatty acids, C8-10(even), C14-18(even) and C16-18(even)-unsatd., triesters with trimethylolpropane (former CAS 85186-89-6) was performed according to DIN 38412 with Pseudomonas putida (Clemes, 1996). This cell multiplication inhibition test determined an EC10 and EC50 (16 h) > 10000 mg/L (nominal). No inhibition on the growth of Pseudomonas putida was observed at the tested nominal concentration of 10000 mg/L. Furthermore, the biodegradation tests exhibit the readily biodegradability of the test substance. Thus, a disturbance in the biodegradation process of a sewage treatment plant is not anticipated.

Based on the results from structurally related read-across substances (in accordance to Regulation (EC) No 1907/2006 Annex XI, 1.5) which are characterized by a similar ecotoxicological profile and comparable structure, it can be concluded that fatty acids, coco, di-and triesters with trimethylolpropane (CAS 85566-29-6) will not exhibit toxic effects to microorganisms and a disturbance in the biodegradation process of a sewage treatment plant is not anticipated.