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Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

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Description of key information

No dose-related effects on the growth rate of Desmodesmus subspicata were observed after 72 h exposure to test concentrations up to 100 mg C.I. Pigment Yellow 34/l. Therefore the LC50 is above the loading rate of 100 mg test substance/liter and the NOEC is at or above 50 mg/l.  

Key value for chemical safety assessment

EC50 for freshwater algae:
100 mg/L
EC10 or NOEC for freshwater algae:
50 mg/L

Additional information

Two guideline studies on the acute toxicity of C.I. Pigment Yellow 34 to the aquatic alga Desmodesmus subspicatus are available (OECD 201, 1984, reliability 2, acceptable restrictions). The test substance was not prepared according to the OECD 29 dissolution protocol (07/2001). It was prepared by stirring 125 mg C.I. pigment Yellow 34 per liter for 24 hours and filtration over 0.2 micrometer. The concentrations of dissolved metals in the eluate were determined. The eluate contents for dissolved chromium, lead and barium were 0.008 - 0.0011 mg chromium/l, 0.005 mg lead/l, and 1.7 - 2.0 mg Ba per liter. No dose-related effects on the growth rate were observed (see attached graphs). The 72h-EC50 for Desmodesmus subspicatus was above the loading rate of 100 mg C.I. Pigment Yellow 34 per liter. The 72h-NOEC for Desmodesmus subspicatus was at or above the loading rate of 50 and 100 mg C.I. Pigment Yellow 34 per liter (BASF AG, 2000).