2-chloropropane

Toxicity to aquatic algae and cyanobacteria

Description of key information

Isopropyl chloride was reported to have low toxicity to aquatic algae, with a 72-hour EC50 based on growth rate of 500 mg/L (measured, arithmetic mean) in a GLP compliant OECD guideline study (Test No. 201).

Key value for chemical safety assessment

EC50 for freshwater algae:

500 mg/L

EC10 or NOEC for freshwater algae:

74 mg/L

Additional information

The ability of isopropyl chloride to inhibit the growth of Desmodesmus subspicatus was determined (Muckle, 2010). The GLP compliant study followed the OECD Guidelines for Testing of Chemicals No. 201. Potassium dichromate was used as the reference substance at concentrations of 0.08, 0.125, 0.2, 0.32, 0.5, 0.8, 1.25, 2.0, and 3.2 mg/L and reported a 72-hour EC50 based on growth rate of 0.90 mg/L. Due to the volatility of the test item, the test was performed in a closed system. As well, the results were based on the arithmetic mean of the measured concentrations and 0-hours and 72-hours. The validity criteria as outlined in OECD 201 were meet, the biomass in the control cultures increased exponentially by a factor of at least 16 within the 72-hour test period (actual factor 158); the mean coefficient of variation for section-by-section specific growth rates in the control cultures did not exceed 35% (actual value 32%); and the coefficient of variation of average specific growth rates during the whole test period in replicate control cultures did not exceed 7% (actual value 1%). Based on the growth rate of Desmodesmus subspicatus, the 72-hour ErC50 is 500 mg/L, the LOEC is greater than 74 mg/L and less than or equal to 180 mg/L, and the NOEC is 74 mg/L.