ISO 20665:2008规定了一种基于（7±1）d后生殖抑制测定对Dubia Ceriodaphnia dubia（枝角类，甲壳类）慢性毒性的方法。 该方法适用于:a)在试验条件下可溶或可保持稳定悬浮液或分散液的化学物质；b)工业或污水流出物，如果合适的话，在倾析、过滤或离心之后；c)淡水；d)水提取物(浸出物、洗脱物和淘析物)。 ISO 20665:2008不适用于河口或海洋环境水生样品的检测。

ISO 20665:2008 specifies a method for the determination of the chronic toxicity to Ceriodaphnia dubia (Cladocera, Crustacea), based on reproduction inhibition after (7 ± 1) d. The method is applicable to: a) chemical substances which are soluble or which can be maintained as stable suspensions or dispersions under the conditions of the test; b) industrial or sewage effluents, if appropriate after decantation, filtration or centrifugation; c) fresh waters; d) aqueous extracts (leachates, eluates, and elutriates). ISO 20665:2008 is not applicable to the testing of aquatic samples from the estuarine or marine environment.