L-menthyl acetate

Endpoint summary

Additional information

There are no data available on the aquatic toxicity ofthe target substance. In order to fulfil the standard information requirements read-across from structurally related substances was conducted in accordance with Annex XI, 1.5, of Regulation (EC) No 1907/2006.

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, 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. Please refer to IUCLID section 13 for a detailed justification of the analogue approach.

The source substance menthyl acetate (CAS 89-48-5) was used for read-across purposes. This substance is a racemic mixture of L-menthyl acetate and D-menthyl acetate thus containing the target substance. The presence of D-menthyl acetate in the mixture is not considered to have a remarkable impact on the assessment of the aquatic toxicity of the target substance. For the structurally similar stereoisomers D- and L-menthol it was shown that their different isomeric structure has no impact on the toxicity profile as discussed and justified in the OECD SIDS report (OECD, 2003). For completeness data from the second source substance L-menthol (CAS 2216-51-5) was used for read-across as well. L-menthol is the expected abiotic hydrolysis product of the target substance L-menthyl acetate. Acetic acid as the second hydrolysis product was not used for read-across purposes since it is not expected to contribute to the overall toxicity profile of the target substance (US HPV, 2001). All ecotoxicological studies discussed in this review resulted in higher effect concentrations compared to the available studies used for read-across for L-menthyl acetate.

Experimental studies with the source substance menthyl acetate (CAS 89-48-5) cover the toxicity to three trophic levels (fish, aquatic invertebrates and algae). All studies were performed according to internationally accepted guidelines and the principles of GLP. Aquatic algae turned out to be the most sensitive species. The study resulted in an ErC50 (72 h) of 2.7 mg/L (meas. (geom. mean) and an ErC10 (72 h) of 0.61 mg/L (meas. (geom. mean). Short-term toxicity testing with freshwater fish resulted in a LC50 (96 h) of 6.72 mg/L (meas. (geom. mean) followed by aquatic invertebrates with an EC50 (48 h) 9.1 mg/L (meas. (arith. mean).The respiration of activated sludge is not considered to be inhibited based on the result of the toxicity control from a standard biodegradation study. No inhibition of degradation was recorded up to a concentration of 2.6 mg/L. Thus, the NOEC (28 d) was derived to be ≥ 2.6 mg/L.
The available studies for the second source substance L-menthol (expected hydrolysis product) resulted in slightly higher effect concentrations. Freshwater fish turned out to be the most sensitive species (LC50 (96 h) 15.6 mg/L (meas. (arith. mean)) followed by aquatic algae (ErC50 (72 h) 21.4 mg/L (meas. (arithm. mean)); NOErC (72 h) 9.65 mg/L (meas. (arithm. mean)) and aquatic invertebrates (EC50 (48 h) 26.6 mg/L (nominal)).