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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 Klimisch 1 acute 72 hr algal study in 2000 conducted according to O.E.C.D. Testing Guideline 201 with GLP compliance and test substance concetration analytical determination is the most appropriate and reliable study on which to base an algal PNEC.  The EC50 value for this study was 3.4 mg.L and the NOEC for this study was 0.42 mg/L.  

Key value for chemical safety assessment

EC50 for freshwater algae:
3.4 mg/L

Additional information

ECHA guidance (RIP 3.2, Chapter R. 10) suggests applying a 1000-fold Assessment Factor to an acute freshwater EC50 value to derive the PNEC. Therefore that freshwater algal PNEC is 3.4 (mg/L)/1000 = 3.4 ug/L. To derive a marine algal PNEC from freshwater algae study data, ECHA guidance recommends an Assessment Factor of 10,000-fold. Therefore, the marine algal PNEC based on the freshwater algal EC50 value of 3.4 mg/L 0.34 ug/L.