Registration Dossier

Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

ErL50 (72 h) > 320 mg/L (nominal, loading rate) for Desmodesmus subspicatus (OECD 201)
NOELR (72 h) = 32 mg/L (nominal, loading rate) for Desmodesmus subspicatus (OECD 201)

Key value for chemical safety assessment

Additional information

No experimental data evaluating the toxicity of Glycerides, C16-18 mono-, di- and tri- (CAS No. 91052-54-9) to algae are available. Therefore, toxicity data from a structurally related category member (Glycerides, C14-18 and C16-18 unsatd. 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. Both areUVCB substances, formed from the esterification of fatty acids and glycerol, having a high content of C18 fatty acids and to a certain extent C16 fatty acids. Furthermore, their water solubilities are comparable (< 0.05 and < 0.15 mg/L for CAS No. 91052-28-7 and CAS No. 91052-54-9, respectively). Therefore, these two substances are expected to show similar behaviour in the water phase and comparable degrees of toxicity to aquatic organisms. Based on the above information, the use of data from Glycerides, C14-18 and C16-18 unsatd. mono-, di- and tri- as read-across is considered justified.

 

One study evaluating the toxicity of Glycerides,C14-18 and C16-18 unsaturated, mono-, di- and tri- (CAS No. 91052-28-7)to algae is available (Salinas, 2013). This test was conducted according to OECD Guideline 201, under GLP conditions. Desmodesmus subspicatus was exposed for 72 hours to the test substance at test concentrations of 3.2, 10, 32, 100 and 320 mg/L (nominal, loading rate). Chlorophyll-a fluorescence (pulsed excitation with light flashes having a wavelength of 430 nm) was the measured test parameter. Nevertheless, cell density was also determined in order to derive the linear correlation between both parameters. After 72 hours of exposure, effects on algal growth rate were observed at concentrations of 100 mg/L and 320 mg/L, leading to an ErL10 of 172 mg/L and a NOELR of 32 mg/L (nominal, loading rate). The ErL50 was determined to be > 320 mg/L (nominal, loading rate). The reported effects are well above the water solubility of the substance (water solubility < 0.05 mg/L) and therefore, they could be caused by physical interference or adsorption between algae and the test substance. Nevertheless, stock solutions were reported to be colourless and clear, and therefore, effects due to toxicity cannot be discarded.

 

Based on the results obtained for the structurally related analogue (in accordance with Regulation (EC) No. 1907/2006, Annex XI, 1.5), Glycerides, C16-18 mono-, di- and tri- (CAS No. 91052-54-9) could exhibit low toxicity to algae.