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Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

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Description of key information


The toxicity of the surrogate test substance 2-methylbutan-1-ol to the freshwater alga Pseudokirchneriella subcapitata was determined also according to the principles of OECD 201 under GLP conditions. After 72 hours the NOEC was determined to be 29 mg/L, the ErC10 was determined to be 132 mg/L and the ErC50 was determined to be greater than 353 mg/L. All values based on measured concentrations.

Key value for chemical safety assessment

EC50 for freshwater algae:
353 mg/L
EC50 for marine water algae:
132 mg/L

Additional information

The toxicity of the test substance 2-methylbutan-1-ol to the freshwater alga Pseudokirchneriella subcapitata was determined also according to the principles of OECD 201 under GLP conditions. The Nominal test concentrations were 0 (control), 3.2, 10, 32, 100 and 320 mg/L and the mean measured concentrations were determined to be < 2 (control), 2.2, 9.6, 29.0, 120 and 353 mg/L. The temperature was measured continuous during the whole test period, pH was measured after 0 and 72 hours. The initial cells density was 0.3 x 10E+04 cells/mL. The algal growth was measured as in vivo chlorophyll-a fluorescence (pulsed excitation with light flashes having a wavelength of 432 nm). The inoculum culture was observed microscopically at the start of the test to verify normal and healthy cells. At test termination, a pooled sample from each test concentration was examined and any abnormal appearance of the algae was noted. After 72 hours the NOEC was determined to be 29 mg/L, the ErC10 was determined to be 132 mg/L and the ErC50 was determined to be greater than 353 mg/L. All values based on measured concentrations.

In addition a read across category approach was done to the other category members.

 

A publication (Bringmann et al. 1977) is available describing the influence of the surrogate test substance pentan-1-ol on the growth of the freshwater algae Scenedesmus quadricauda. The study was conducted under static conditions. The 8 days EC50 was determined to be 260 mg test item/L. No EC10 value is available from this study.

 

Furthermore the toxicity of the surrogate test substance pentanol, branched and linear (CAS 94624-12-1) to the freshwater alga Pseudokirchneriella subcapitata was determined according to the principles of OECD 201 under GLP conditions. The aim of the study was to assess the effects on growth rate and yield over a period of 72 hours. After 72 hours the NOEC, the EC10 and the EC50 were determined to be greater than 320 mg/L.

 

Supplementary the toxicity of the surrogate test substance 3-methylbutan-1-ol Scenedesmus subspicatus (new name: Desmodesmus subspicatus) was determined also according to DIN 38412 part 9 under Non-GLP conditions. After 72 hours the ErC10 was determined to be 141 mg/L and the EC50 was determined to be greater than 500 mg/L (growth rate) and 493 mg/L (biomass). All values based on nominal concentrations.

 

In conclusion the 72h-EC50 and the 72h-EC10 value of the test substance and of the read across category members was determined to be greater than 100 mg/L.