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Description of key information

 Jenkins (1990) showed the EC50 for tert-dodecanethiol could not be calculated as it was not inhibitory to activated sludge at the highest concentrations tested, that is 10 g/l.

Key value for chemical safety assessment

EC10 or NOEC for microorganisms:
10 g/L

Additional information

Jenkins (1990), performed a 3 -hour, static, freshwater, GLP-compliant test, testing oxygen consumption, following OECD guideline 209. The validity criteria were fulfilled. The study is considered reliable with restrictions (a shorter study period may have been preferable for this volatile substance) and adequate for assessment. In two series of assays, between 1 and 100 mg/L, and between 0.5 and 10 g/L there was no inhibition of sludge respiration. Therefore NOEC and EC50 are greater than 10 g/L

This is backed up by another study by Gancet (2010), a GLP-compliant activated sludge respiration inhibition test following OECD guidelines 209 although the author only tested to 8.6 mg/L, already far higher than the water solubility limit. The study has been assigned a Klimisch score of 2 - reliable with restrictions (Klimisch et al, 1997) for the same reason and is considered reliable and suitable for use for this endpoint.