Registration Dossier

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Additional information

Experimental data are available for the toxicity of tert-dodecanethiol to freshwater aquatic species .

For algae, with WAFs, no EL50 -72h could be calculated but a NOELR of 3.2 mg/L was calculated but cannot be used as the study is technically flawed. Further studies on algae are waived on a technical basis.

For invertebrates (daphnia), from a single valid study (CERI, 2000) an EC50 48h of >0.56 mg/L was obtained but this was far higher than the limit of solubility.

For fish no valid data are available but a weight of evidence approach allows us to conclude that there was no effect at the limit of solubility of the substance.

No effects were found at any concentration close to the water solubility of the substance and therefore all effects are considered to be >solubility limit for both acute and available chronic toxicity data (algae and daphnids). There is no reason to expect the substance will be significantly more toxic to fish than to algae or daphnids in a chronic study.

Additionally, a NOECwater can be calculated by EPM, according to equation 11-1 in Guidance R.11, using data available in the dataset: NOECsed = 300 mg/kg dw = 65.2 mg/kg wwt and Koc = 3981 L/kg. From this calculation, it comes: NOECwater = 0.747 mg/L largely above water solubility (WS = 0.00393 mg/L), showing unlikelihood of toxicity to pelagic organisms.

Taking into account that the substance is not readily/rapidly biodegradable and has a BCF confirmed experimentally at >500, tert-dodecanethiol can be classified only as Category Chronic 4 under CLP (regulation 1272/2008 and 286/2011), with the hazard statement H413: May cause long lasting harmful effects to aquatic life.

Under DSD the equivalent classification is R53 " May cause long-term adverse effects in the aquatic environment".