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Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

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Link to relevant study record(s)

Description of key information

The toxicity of propane-1-thiol to algae has been read across from ethanethiol. Effect concentrations for the toxicity of ethanethiol to Pseudokirchneriella subcapitata were: EbC50 72 hr biomass 0.75mg/L; NOECb 0.83 mg/L; EbC10 0.13 mg/L; ErC50 72 hr growth rate 3.0 mg/L; NOECr 0.83 mg/L; ErC10 0.55 mg/L.

Key value for chemical safety assessment

EC50 for freshwater algae:
3 mg/L

Additional information

The toxicity of propane-1-thiol to algae has been read across from ethanethiol. The Thiebaud (2000) study is GLP compliant and has been done to guideline but is not considered to be fully relevant for risk assessment purposes. The test substance was not maintained within 80% of nominal concentrations, so a geometric mean value was calculated using the initial and final concentrations. The NOEC for both biomass and growth rate were determined using a statistical analytical method (Dunnett test), and the EC10 and EC50 were determined by Probit analysis. The EC10 and EC50 for biomass and the EC10 for growth rate were extrapolated below the measured concentrations, and therefore caution should be taken when using these values. Nevertheless, the study has been considered reliable, with a Klimisch score of 2 by the IUCLID dataset 30.09.2009 and is a critical study for the OECD SIDS Initial Assessment Report C2 -C4 Aliphatic Thiols for SIAM 30 (April 2010).