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Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

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Description of key information

With high probability acutely not harmful to algae.


Long-term effects are not to be expected.

Key value for chemical safety assessment

Additional information

The toxicity of N-Methylpiperazine to the unicellular freshwater green alga Desmodesmus subspicatus was determined according to OECD TG 201 (Noack, 2013; study number SSO14703). The aim of the study was to assess the effects on growth rate and yield over a period of 72 hours. The study was conducted under static conditions with an initial cell density of 4332 cells/mL. Based on a preliminary test 5 concentration levels were tested in a geometrical series with a dilution factor of √10(nominal): 3.16 - 10.0 - 31.6 - 100 - 316 mg/L. The concentrations of N-Methylpiperazine were analytically verified by UPLC-MS/MS at test start and test end of all test concentrations and the control. The measured concentrations of N-Methylpiperazine at test start were in the range of 105 to 118 % and after 72 hours in the range of 115 to 120 % of the nominal values. All effect values given are based on the geometric mean measured concentrations.


Growth rate: The 72-h ErC10 and the 72-h ErC50 were determined to be greater than 352 mg/L (geomean. meas.).


Yield: The 72-h EyC10 was determined to be 164 mg/L (95% CI: < 35.2-223 mg/L). The 72-h EyC50 was determined greater than 352 mg/L (geomean meas.). 


It can be concluded that the substance is acutely not harmful to aquatic algae. Long-term effects are not to be expected.