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Ecotoxicological information

Long-term toxicity to fish

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Link to relevant study record(s)

Description of key information

There are 2 key studies available and following is a brief from both -

A test was conducted to estimate the potential chronic toxicity of 2 -methyl-4 -isothiazolin-3 -one (supplied as a 50% solution in water known as Kordek 573F Industrial Microbiocide) to the early lifestages of the rainbow trout, Oncorhynchus mykiss. The no-observed-effect concentration (NOEC) for egg hatchability and survival was 4.93 mg a.i./l. The lowest-observed-effect concentration (LOEC) for egg hatchability and survival was 9.88 mg a.i./l. At 62 days post-hatch, a statistically significant reduction in standard length and blotted wet weight (growth) was detected at a concentration of 4.93 mg a.i./l when compared to the control. The NOEC and LOEC values for growth (length and weight) were 2.38 and 4.93 mg a.i./l, respectively. The maxim

um acceptable toxicant concentration (MATC) for 2 -methyl-4 -isothiazolin-3 -one, based on growth, was estimated to be 3.43 mg a.i./l.

A test was conducted to estimate the potential chronic toxicity of 2 -methyl-4 -isothiazolin-3 -one to the early lifestages of fathead minnow, Pimephales promelas. The dose-response relationship revealed a high toxicity level to fathead minnow and the endpoints based on mean measured concentrations were NOECsurvival = 2.1 mg as/L and LOECsurvival = 4.2 mg as/L

Key value for chemical safety assessment

EC10, LC10 or NOEC for freshwater fish:
4.93 mg/L

Additional information