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Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Cyclohexanol exhibited effects to aquatic invertebrates (Daphnia magna) in standard aquatic toxicity studies conducted to GLP and OECD Testing Guidelines. The substance is classified for long-term aquatic hazard, Chronic Category 3, in accordance with the criteria for classification as defined in Annex I, Regulation (EC) No 1272/2008, as amended by Commission Regulation (EU) No 286/2011.

Additional information

Results on acute aquatic toxicity are available for the three trophic levels of fish, daphnia and algae. A chronic study on Daphnia magna is also available. The following endpoints have been selected for determining the hazard potential of cyclohexanol towards aquatic organisms on the basis of their reliability:


LC50 (96 hours) 704 mg/L, measured, Pimephales promelas, Brooke et al. 1984


EC50 (48 hours) 17 mg/L, measured, Daphnia magna, SafePharm, 2003

NOEC (21 days) 0.953 mg/L, measured, Daphnia magna, Smithers Viscient, 2016


EC50 (72 hours) >500 mg/L, nominal, Scenedesmus subspicatus, BASF AG 1988

Cyclohexanol exhibited harmful effects to Daphnia magna, resulting in an EC50 (48 h) value of 17 mg/L (measured concentration) and a NOEC (21 d) value of 0.953 mg/L. This chronic NOEC represents the most sensitive endpoint for aquatic effects and is therefore used for the derivation of PNECs.

Results of toxicity tests towards aquatic microorganisms show that cyclohexanol is not harmful to bacteria. This was established in tests performed according to standard guidelines (BASF AG 1981, 1987).

EC20 (30 min) >1995 mg/L, nominal, industrial activated sludge, BASF AG 1981

EC10 (17 h) 470 mg/L, nominal, Pseudomonas putida, BASF AG 1987

Therefore, the inhibition of degradation activity of activated sludge is not anticipated when cyclohexanol is introduced in appropriately low concentrations.