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Description of key information

Key value for chemical safety assessment

Additional information

The approx. LD50 for acute oral toxicity in the rat is between 1890 (test with 2 - 50% aqueous emulsion with traganth) and 2650 mg/kg (test with solution in olive oil). Clinical signs were prone and lateral position and narcosis. Pathology showed no abnormal findings. This test was carried out according to BASF-internal standards (testing date: 1966; no data about sex of the animals are available).

Smyth et al. (1969) found an acute oral LD50 value of 1620 mg/kg for male rats (gastric intubation). No data are given for mortalities in single dose groups, clinical signs or gross pathology. All other data/studies available for this route of exposure showed LD50 values near or below 2000 mg/kg.

An LC50 value of > 6.2 mg/l/4 hours for both sexes (rat) was found in an acute inhalation study (BASF-internal standards). No mortalities were seen. Clinical signs were watery eye and nose secretion, mouth smearing, intermittent and accelerated breathing, apathetic, narcosis, scrubby fur. Theses symptoms were seen until day of sacrifice. These data would not indicate a classification for this exposure route.

No available data have been obtained for the dermal exposure route according to present testing guidelines (semiocclusive; 4 hrs exposure time). From the chemical structure and the physical-chemical properties, however, a ready dermal absorption and, hence, a toxicity of similar order of magnitude as from oral administration can be assumed. There is also evidence, that humans metabolize Cyclohexanone in partially different pathways as rats. It appears therefore to be prudent to classify Cyclohexanon also for the dermal exposure route.

Justification for classification or non-classification

The test substance is classifed according to Annex I to the Directive 67/548/EEC with R 20 (harmful if inhaled).

Proposal for further classification: R 22 (harmful if swallowed) and R 21 (harmful in contact with skin).