Use of this information is subject to copyright laws and may require the permission of the owner of the information, as described in the ECHA Legal Notice.
EC number: 200-835-2 | CAS number: 75-05-8
Survival of male mice exposed to 200ppm was significantly greater than that of the control mice. The incidence of squamous cell hyperplasia of the forestomach was increased in both sexes at 200ppm (12/50 males and 19/50 females, compared to 2-3/49 for controls). However, the incidence of squamous cell papilloma was only slightly increased at this exposure level, and was within the range of historical controls.
In a cancer bioassay conducted by the US National Toxicology Program, inhalation exposure to the maximum tolerated dose of acetonitrile vapor for 2 years produced no evidence of carcinogenic activity in male or female B6C3F1 mice. Groups of 60 male and 60 female mice were exposed to 0, 50, 100 or 200 ppm acetonitrile vapor 6 hours per day, 5 days per week for 2 years. Two-year survival of exposed male and female mice was similar to that of the controls, except that the survival of male mice in the 200 ppm group was significantly greater than that of the controls. Mean body weights and organ weights of exposed groups were similar to those of the controls, and no clinical observations in any group were clearly related to acetonitrile exposure. The incidence of squamous hyperplasia of the epithelium of the forestomach was significantly increased at 15 months in 200 ppm females. At 2 years, the increased incidence of this lesion was dose related in the 100 and 200 ppm male groups and in all exposed female groups. Hyperplasia seen in the forestomach is considered an adverse finding, but is likely not a result of inhalation. Grooming of contaminated fur or mucocillary clearance followed by ingestion likely played a central role in this finding, although a role for inhalation cannot be ruled out and represents an area of uncertainty. Because of this uncertainty, a NOAEC for this endpoint cannot be identified. The NOAEC for other endpoints in this study is 200 ppm.
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.
Welcome to the ECHA website. This site is not fully supported in Internet Explorer 7 (and earlier versions). Please upgrade your Internet Explorer to a newer version.
Close Do not show this message again