VANADIUM PENTOXIDE FUME
OSHA comments from the January 19, 1989 Final Rule on Air Contaminants Project extracted from 54FR2332 et. seq. This rule was remanded by the U.S. Circuit Court of Appeals and the limits are not currently in force.
CAS: 1314-62-1; Chemical Formula: V2O5
OSHA’s former PEL for vanadium pentoxide fume was 0.1 mg/m3 as a ceiling limit. The Agency proposed to revise this limit to 0.05 mg/m3 as an 8-hour TWA, based on the ACGIH recommendation. OSHA is establishing this limit in the final rule.
Vanadium pentoxide fume’s chief toxic effects are manifested in the respiratory passages: bronchitis, emphysema, tracheitis, pulmonary edema, and bronchial pneumonia can result from exposure. According to Hudson (1964/Ex. 1-880), vanadium is poisonous to all animals by all routes of administration. The LD(50) in rabbits injected intravenously is 1.5 mg/kg, and rats fed 25 ppm demonstrated toxic responses within a short time (Hudson 1964/Ex. 1-880).
Seven cases of upper respiratory tract irritation were reported in boiler cleaners exposed to concentrations of from 2 to 85 mg/m3 vanadium pentoxide fume (Sjoberg 1951/Ex. 1-437). Williams (1952/Ex. 1-456) reported eight cases of vanadium poisoning in workers cleaning boilers in an atmosphere ranging from 30 to 104 mg/m3. Gul’ko (1956, as cited by Hudson 1964/Ex. 1-880) observed eye and bronchial irritation in workers exposed to 0.5 to 2.2 mg/m3. A study by Lewis (1959/Ex. 1-345) indicated that workers exposed to levels of 0.2 to 0.5 mg/m3 experienced a higher incidence of respiratory symptoms than did controls. Tebrock and Machle (1968/Ex. 1-446) reported that workers exposed to average concentrations of 1.5 mg/m3 vanadium pentoxide in a mixed dust developed conjunctivitis, tracheobronchitis, and dermatitis. A single average eight-hour exposure to 0.2 mg/m3 respirable vanadium dust caused severe upper respiratory tract irritation in five human volunteers, and two other subjects exposed to a 0.1-mg/m3 concentration also developed delayed cough and an increase in mucous production (Zenz and Berg 1967/Ex. 1-405).
NIOSH (Ex. 8-47, Table N7) recommended a 15-minute ceiling limit of 0.05 mg/m3 for vanadium fume as vanadium pentoxide. However, OSHA is concerned about cumulative exposures below the former 0.1 mg/m3 ceiling, and the Agency concludes that the TWA limit originally proposed will protect workers from the significant risks of eye, skin, and upper respiratory tract irritation; conjunctivitis; pulmonary damage; and systemic poisoning associated with exposure to vanadium pentoxide fume at even brief excursions to higher levels. The Agency considers these irritant and systemic effects to be material impairments of health. Accordingly, OSHA is establishing a PEL of 0.05 mg/m3 as an 8-hour TWA for this substance in today’s rule.