Dimethyl sulphate

Endpoint summary

Additional information

EU RISK ASSESSMENT – DIMETHYL SULPHATE

Short term toxicity to fish

In all studies with aquatic organisms the observed toxicity concerns the toxicity of DMS and its hydrolysis products (methyl sulphate and methanol).

For a static study (temperature 23°C, pH 7.6-7.9, hardness 55 mg/l as CaCO3) with Lepomis macrochirus (33-75 mm) a “best fit” 96-hour LC50 of 7.5 mg/l is reported (Dawson et al., 1977). This value is derived from a concentration-effect range that is considered not reliable. At 7.5 mg/l the survival percentage is 90%. For Leuciscus idus melanotus(1.6-2.6 g, static test, pH 7.5-8.4, hardness 110 mg/l as CaCO3) the LC50is 14 mg/l (Hoechst, 1981).

There are no long-term tests available either for freshwater or marine fish.

In a static test in artificial seawater (salinity not reported, temperature 20°C) with Menidia beryllina the “best fit” 96-hour LC50 is 15 mg/l (Dawson et al., 1977). The behaviour pattern of the marine fish Kuhlia sandvicensis was tested after exposure to DMS at a concentration up to 20 mg/l (Hiatt et al., 1953). Only at the highest dose of 20 mg/l a slight reaction (e.g. mouth movements, vertical swimming) was reported.

Genetic effects were observed in fish embryos following treatment of sperm with DMS and disturbances in the nucleoli of oocytes from fish have been reported following exposure to DMS contaminated water (EHC, 1985).

 

Acute toxicity to aquatic invertebrates (e.g. Daphnia)

In a study with Daphnia magna, performed according to OECD guidelines, the 48-hour EC50 is 17 mg/l (Hoechst, 1990). No details on test water and test conditions are available.

 

Toxicity to aquatic plants (e.g. algae)

In a study with Scenedesmus subspicatus, performed according to OECD guidelines (pH 6.1-8.4, temperature 24°C), the 72-hour EC50 for growth rate is 46.9 mg/l (Hoechst, 1988).

 

Toxicity to microorganisms (e.g. bacteria)

In an activated sludge test, performed according to OECD guidelines (pH 7, temperature 23°C), the 3 hour-EC50 for bacterial respiration inhibition is 377 mg/l (Hoechst, 1990).

In a test for the determination of damage to anaerobic effluent bacteria (fermentation tube method) a toxicity threshold limit of 2000 mg/l is given (Hoechst, 1980). Too little information is available to check the reliability of this test.