NIOSH has recommended that employee exposure to acrylonitrile (107131) be limited to not more than 4 parts per million or 8.7mg/m3, in air as determined by a 4 hour sample collected at 0.2 liters/minute. Studies have indicated that acute effects of acrylonitrile exposure are similar to those of exposure to cyanide. Damage to animals has included the central nervous system, lungs, liver, and kidneys. Mice have demonstrated embryotoxic effects. A 2 year feeding study in rats indicated acrylonitrile caused the development of central nervous system tumors and Zymbal gland carcinomas. An epidemiological study of 470 acrylonitrile polymerization workers in the textiles industry indicated increased risk for lung and colon cancer. The major use for acrylonitrile in the United States has been in the production of acrylic fibers which are used in making apparel, carpeting, blankets, draperies, and upholstery. Some fibers were also used in synthetic furs and for wigs. Recommendations were included for the medical surveillance of workers, labeling and posting of hazards, use of personal protective clothing and equipment, education of employees concerning hazards, general work practices, proper sanitation, monitoring, and expected record keeping.