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Description of key information

Repeat dose toxicity information is only available via the inhalation route. The key study for the inhalation route (Nitschke et al, 1980) reported a NOEC value of 3ppm. Based upon a molecular weight of 187.8612 a value of 3ppm is equal to 23.05mg/m^3.

Key value for chemical safety assessment

Repeated dose toxicity: inhalation - systemic effects

Endpoint conclusion
Dose descriptor:
23.05 mg/m³
Study duration:

Additional information

Nitschke et al, 1980, was selected as the key study for the repeat dose toxicity endpoint. The study was conducted in a similar manner to the OECD 413 guideline (Subchronic inhalation toxicity: 90-day), however the exposure period was extended to 13 weeks (95-96 days). This deviation was considered not to affect the reliability of the result and the study was therefore awarded a reliability score of 1.

The Nitschke et al, 1980, study was conducted on rats using test concentrations of 3, 10 and 40ppm. 40 male and 20 female rats were tested per dose level, a concurrent control group was also used for comparison of results.

The registered substance produced a reduction in body weight, adverse effects on the respiratory system, nasal turbinates and liver at 40 ppm. At 10ppm the registered substance produced adverse effects on the respiratory system, however at 3ppm no effects were observed. The NOEC was therefore set at 3ppm.

Nitschke et al (1981), Rowe et al (1952) and Wong et al (1980) are provided as supporting information only.

Nitschke et al, 1981, was a publication of the Nitschke et al, 1980, study. The publication provided less information than the study report and was therefore considered less reliable than the study report. All results and conclusions reported in the Nitschke et al, 1981, were equal to those reported in the study report Nitschke et al, 1980.

Rowe et al, 1952, was conducted on rats, rabbits, guinea pigs and monkeys exposued to concentrations of 25, 50 or 100ppm for 7 hours, 5 days per week for 6 months. A NOAEC of 25ppm was set for rabbits and monkeys. Four of the guinea pigs died of a pulmonary infection during the course of the study. 50% of the male rats and 3 of the female rats died during the study due to pneumonia and infections of the upper respiratory tract.

Wong et al, 1980, was conducted on rats with disulfiram added to the diet of the test animals. Animals were exposed to 20ppm concentrations 5 days per week for 18 months. It was concluded that the 20ppm exposure had an adverse effect on the test animals, toxic effects were enhanced by addition of disulfiram to the diet.

Justification for classification or non-classification