Registration Dossier

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Additional information

There is no data on D-menthol concerning the aquatic toxicity endpoint. The evaluation is based on the L-menthol and we used the read-across for this endpoint due to the comparable profiles.

Justification for Read-across:

Based on the comparable profiles on OECD-Toolbox of the different menthols we can use them for read across studies. These isomers are L-menthol (CAS 2216-51-5), D-menthol (CAS 15356-60-2) and DL-menthol (CAS 89-78-1)

Moreover, a comparative physico-chemical profile of these isomers reinforces this similarity. As structural isomers, the members of the menthol category share the same molecular weight. Of particular importance to environmental  effects and human effects are the values for partition coefficient (log Kow around 3), vapour pressure (from 17 Pa at 25°C for the DL-menthol to 21 Pa 25°C for the natural L-menthol ) and water solubility ( moderately soluble from 410 mg/l at 25°C for the natural L-menthol to 470 mg/l at 25°C for the DL-menthol). The read across is consistent based on these physico-chemical parameters.

Results from L-menthol:

The experimental short-term ecotoxicological data are available for the following aquatic species on L-menthol:

Fish : LC50 at 96h = 15,6 mg/l

Daphnia : EC50 at 48h = 26,6 mg/l

Algae : EC 50 at 72h = 21,4 mg/l with a NOEC at 9,65 mg/l

The effective concentration 50% (EC50) for inhibition of activated sludge respiration was determined as 237 mg/L. In view of this low bacteriotoxic activity, it was concluded that release of the test compound into the environment would most likely not adversely affect the natural self purification capacity of surface water bodies.

There are no long term toxicity data on aquatic species or on terrestrial species.Therefore the PNEC is based on the available acute toxicity data with the related assesment factor