Freshwater Alga and Cyanobacteria, Growth Inhibition Test (OECD TG 201)
The Freshwater Alga and Cyanobacteria Growth Inhibition Test according to OECD TG 201 is designed to assess the toxic effects of substances on primary producers in aquatic ecosystems. Algae and cyanobacteria play a crucial role at the base of the food web, making this test highly relevant for environmental risk assessment.
In this study, exponentially growing cultures of selected freshwater algal or cyanobacterial species are exposed to a range of test substance concentrations over a typical period of 72 hours. Growth is monitored by measuring parameters such as cell density, biomass, or optical density.
The objective is to establish concentration–response relationships and to determine key endpoints, including the median effective concentration (ErC₅₀) and the No Observed Effect Concentration (NOEC).
This test provides essential data for evaluating the potential impact of chemicals on aquatic ecosystems, particularly with regard to effects on primary production.
