Glycerides, mixed coco, decanoyl and octanoyl

Short-term toxicity to aquatic invertebrates

Description of key information

No effects up to the limit of water solubility (WS 0.05 mg/L)

Additional information

No experimental data evaluating the acute toxicity of Glycerides, mixed coco, decanoyl and octanoyl (CAS No. 68606-18-8) to aquatic invertebrates are available. Therefore, toxicity data from analogue category members, propane-1,2,3-triyl trisheptanoate (CAS No. 620-67-7) and Glycerides,C14-18 and C16-18 unsaturated, mono-, di- and tri- (CAS No. 91052-28-7), are used as read-across in accordance with Regulation (EC) No. 1907/2006, Annex XI, 1.5. Glycerides, mixed coco, decanoyl and octanoyl is mainly a triglyceride formed by the combination of fatty acids of different C-chain lengths (C6 to C18 unsaturated) and glycerol. Propane-1,2,3-triyl trisheptanoate (CAS No. 620-67-7) is also a triglyceride with fatty acid chain length of C7. For Glycerides,C14-18 and C16-18 unsaturated, mono-, di- and tri- (CAS No. 91052-28-7) the triester content is lower than for the other two substances (up to 15%), with a predominant monoester content. The lower degree of esterification might have an effect in the bioavailability to aquatic organisms, due to a reduced size of the molecules, the potential to cross biological membranes is expected to increase. Therefore, Glycerides,C14-18 and C16-18 unsaturated, mono-, di- and tri- can be regarded as a worst-case read-across substance.The behaviour of these three substances in the water phase is expected to be very similar based on low water solubility values (< 0.05 mg/L for all) and log Pow (> 4). The two read-across substances cover the whole fatty acid C-chain range present in Glycerides, mixed coco, decanoyl and octanoyl. Therefore, they are considered to give a reliable indication of the toxicity of this substance to aquatic organisms, and the read-across is justified.

One study evaluating the acute toxicity of propane-1,2,3-tryil trisheptanoate (CAS No. 620-67-7) to aquatic invertebrates is available (Scholz, 1993). This test was conducted according to EU Method C.2, under GLP conditions. Daphnids were exposed for 48 hours to the test substance within a static water regime, at nominal concentrations ranging from 0.53 to 3.94 mg/L. No significant immobilization effects were observed in the treatment groups (only 1 immobilised daphnid at 3 out of 7 concentrations) nor in the controls (no immobilization) and therefore, the resulting EC50 (48 h) was found to be > 3.94 mg/L (measured concentration). The determination of measured test concentrations was performed by DOC (Dissolved Organic Carbon) analysis, which is more suitable for substances with higher water solubility. The high reported measured concentration (3.94 mg/L) despite the low water solubility of the substance (< 0.05 mg/L) shows that probably other constituents from the solution have been accounted for as test substance. Nevertheless, since no significant effects were observed it can be stated that no acute toxicity to aquatic invertebrates within the range of the water solubility of propane-1,2,3-tryil trisheptanoate is expected.The acute toxicity of Glycerides,C14-18 and C16-18 unsaturated, mono-, di- and tri- (CAS No. 91052-28-7)to aquatic invertebrates has been evaluated by Salinas (2013). This test was conducted according to OECD 202, under GLP conditions. Daphnia magna was exposed to the substance at a single loading rate of 100 mg/L (limit test) for 48 hours within a static water regime. At the end of the exposure period, no immobilization was observed. Therefore, the EL50 (48 h) was determined to be > 100 mg/L (nominal, loading rate).

Based on the results obtained for the structurally related category members (in accordance with Regulation (EC) No. 1907/2006, Annex XI, 1.5), no acute toxicity of Glycerides, mixed coco, decanoyl and octanoyl (CAS No. 68606-18-8) to aquatic invertebrates up to the limit of its water solubility (< 0.05 mg/L) is expected.