2-methylbutan-1-ol

Short-term toxicity to aquatic invertebrates

Description of key information

The acute toxicity of the test substance 2-methylbutan-1-ol on aquatic invertebrates was investigated under GLP conditions according to OECD 202. The 48h-EC50 value was determined to be greater than 173 mg/L (value based on measured concentration). 

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

173 mg/L

Additional information

The acute toxicity of the test substance 2-methylbutan-1-ol on aquatic invertebrates was investigated under GLP conditions according to OECD 202. The nominal test concentration was 120 mg/L and the mean measured concentration was determined to be 173 mg/L. The study encompassed 4 replicates per concentration and 4 replicates per control. The number of the organisms per vessel was 5. The pH and oxygen content were measured at the start of the exposure and at the end of the exposure in replicate 1 of all test concentrations and the control. Temperature was measured continuously during the whole period in a separate vessel. The mobility of the Daphnia was determined after 0, 24 and 48 hours. The 48h-EC50 value was determined to be greater than 173 mg/L (value based on measured concentration).

In addition the short-term toxicity to aquatic invertebrates of the other category members was assessed.

In the acute immobilization test with Daphnia magna (STRAUS), the effects of the surrogate test substance pentan-1-ol were determined according to Regulation (EC) No 79/831/C2 under non GLP conditions. The mobility of the Daphnia was determined in a static 48-hour test by visual observation after 3, 6, 24 and 48 hours. The 48h-EC50 value was determined to be nominal 341 mg test item/L.

Supplementary the acute toxicity of the surrogate test substance 3-methylbutan-1-ol to Daphnia magna was assessed according to DIN 38412 L11. The 48 h-EC50 value was determined to be nominal 255 mg test item/L.

Study results are also available for the fourth category member pentanol, branchend and linear. The EC50 value of this substance was determined to be greater than 120 mg/L in a GLP guideline study with Daphnia magna according to OECD 202.

In conclusion the 48h-EC50 value of the test substance and of the read across category members was determined to be greater than 100 mg/L. As the EC50 value determined with the read-across substance 3-methylbutan-1-ol was lower than the EC50 value determined in the study with the target substance itself, the smaller value was chosen as “key value” and also used for PNEC derivation, reflecting a worst case scenario.