ISO 19820:2016 specifies a method for the determination of the lethal effects of toxicants to Brachionus plicatilis after 24 h or 48 h exposure. The method is applicable to the following: a) chemical substances which are soluble or which can be maintained as a stable suspension of dispersions under the conditions of the test; b) industrial or sewage effluents, treated or untreated, if appropriate after decantation, filtration, or centrifugation; c) marine or estuarine waters; d) sediment elutriates/eluates.