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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 lowest threshold level (comparable to an 8-d NOEC/EC3) was 550 mg/l in the cyanobacterium (blue-green alga) Microcystis aeruginosa . Other studies who far higher effect concentration. therefore the lowest was used in a weight of evidence way.

Key value for chemical safety assessment

EC10 or NOEC for freshwater algae:
550 mg/L

Additional information

Three studies are reported for algae. They are under discussion of being used for the assessment, either because of short duration (Hutchinson et al., 1978), the use of a non standard endpoint (toxicity threshold, Bringmann and Kühn, 1978) or because of lack of information (Bayard et al., 1985), and all were based on nominal concentrations. Although some of the studies used closed vessels, there was a significant headspace which would allow loss by volatility. However, the toxicity threshold values reported for Microcystis aeruginosa and Scenedesmus quadricauda are approximately equivalent to NOEC/EC3 values and are sufficient to indicate that algae are probably less sensitive to dichloromethane than fish or invertebrates. The study with Microcystis aeruginosa has the lowest effect concentration and will be used in the assessment.