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Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

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Description of key information

Key value for chemical safety assessment

EC50 for freshwater algae:
4.5 mg/L
EC10 or NOEC for freshwater algae:
1.48 mg/L

Additional information

The determination of the growth inhibition of the freshwater algaePseudokirchneriella subcapitata (previously known as Raphidocelis subcapitata and Selenastrum capricornutum) exposed to the test item AZDN for a duration of 72 hours was assessed according to the OECD Guideline 201, in a recent study carried out in 2010.

Algae were exposed to 1 to 75 mg/L of AZDN dissolved in dilution water. The toxic effect measured during the assay was the inhibition of cellular multiplication over a time period of 72 hours.

The concentrations of test item causing a 50 % reduction in biomass (EbC50) and in growth rate (ErC50) were estimated to be 3.9 and 4.5 mg/L respectively. It was possible to determine the No Observable Effect Concentrations (NOEC) which is 1.48 mg/L for both biomass and growth rate.

In another study carried out in Japan, growth inhibition concentration based on the growth rates were: ErC50 (24 -48h) >9.4mg/L; NOEC (growth rate method: 24-48h): 9.4 mg/L: ErC50 (24 -72h): >9.4mg/L; and the NOEC at 24 - 72h was 2.1mg/L.