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Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

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Description of key information

Determination of the acute toxicity of FAT 20341/A TE on algal growth inhibition.

Key value for chemical safety assessment

EC50 for freshwater algae:
100 mg/L
EC10 or NOEC for freshwater algae:
50 mg/L

Additional information

The study was performed to assess the effect of FAT 20341/A TE on the growth of the green alga Pseudokirchneriella subcapitata

Following preliminary range-finding tests,Pseudokirchneriella subcapitatawas exposed to an aqueous solution of FAT 20341/A TE at concentrations of 6.25, 12.5, 25, 50 and 100 mg/L (three replicate flasks per concentration) for 72 hours, under constant illumination and shaking at a temperature of 24 ± 1 °C.


Samples of the algal populations were removed daily and cell concentrations determined for each control and treatment group, using a Coulter®Multisizer Particle Counter.


Analysis of the test preparations at 0 and 72 hours showed measured test concentrations to range from 97% to 108% of nominal and so the results are based on nominal test concentrations only.


Exposure ofPseudokirchneriella subcapitatato the test item gave the following results:


Response Variable


No Observed Effect Concentration (NOEC) (mg/L)

Lowest Observed Effect Concentration (LOEC) (mg/L)

Growth Rate








* It was not possible to calculate an ErC50value as no concentration tested resulted in greater than 50% inhibition of growth rate.