OSHA formerly regulated ammonium sulfamate under its generic limit of 15 mg/m3 as total particulate. The ACGIH has established a limit of 10 mg/m3 for this substance as an 8-hour TWA. The final rule establishes a limit of 10 mg/m3 (and 5 mg/m3 for the respirable fraction) for ammonium sulfamate, which is the limit the Agency proposed. NIOSH (Ex. 8-47, Table N4) concurs with this limit. Ammonium sulfamate is a noncombustible, white, crystalline substance.
Lehman (1951/Ex. 1-790) found oral LD(50)s of 3900, 5700, and 3000 mg/kg in rats, mice, and quail, respectively. He also reported that no effects were noted in rats administered 10,000 ppm ammonium sulfamate in the diet for 105 days. The hazards associated with exposure to ammonium sulfamate include eye and nose irritation, interference with vision, and the danger of accidents caused by the distraction and avoidance reactions typical of workers overexposed to dusts in the workplace. Only NIOSH commented on ammonium sulfamate.
OSHA is establishing a PEL of 10 mg/m3 TWA, total particulate, and retaining the 5-mg/m3 TWA PEL for respirable particulate for ammonium sulfamate. The Agency concludes that these limits will protect workers against the significant risk of material health impairment in the form of physical and other irritation that is associated with exposure to this substance.