Acute Toxicity of Chlorpyrifos to the Cladocerans Ceriodaphania dubia and Daphnia magna

Acute 48-h renewal toxicity tests with chlorpyrifos were conducted using the cladocerans Ceriodaphnia dubia and Daphnia magna as the test organisms. The toxicity tests were conducted to generate median effect concentration values at 24 and 48 h of exposure. The tests were conducted at the University of Wisconsin-Superior testing facilities according to procedures recommended by the American Society for Testing and Materials (ASTM 1993)