Six month inhalation exposures of rats and guinea pigs to aluminum chlorhydrate.

Groups of rats and guinea pigs were exposed, by inhalation, to 0.25, 2.5, and 25 mg/m3 of aluminum chlorhydrate (ACH) for six months to study the effects of a common component of antiperspirants. Similar groups of animals of both species exposed to clean air served as controls. The ACH was generated as a particulate dust using a Wright dust feed mechanism. After six months of exposure, animals were sacrificed. Decreases in body weight were seen in rats exposed to 25 mg/m3 of ACH. Marked increases in lung weights and significant increases in lung to body weight ratios were seen in rats and guinea pigs exposed to 25 mg/m3 of ACH. The lungs of all rats and guinea pigs showed significant dose-related increases in aluminum accumulation when exposed to either 0.25, 2.5, or 25 mg/m3 of ACH. The lungs of all rats and guinea pigs exposed to either 2.5 or 25 mg/m3 of ACH contained exposure-related granulomatous reactions characterized by giant vacuoled macrophages containing basophilic material in association with eosinophilic cellular debris.