An in depth industrial hygiene survey was conducted to evaluate occupational health hazards in the phosphate fertilizer industry (SIC-2874). Four fertilizer factories and one phosphate ore mining and beneficiation facility were studied. Samples were collected for phosphoric-acid (7664382), sulfuric-acid (7664939), fluoride, cadmium (7440439), chromium (7440473), uranium (7440611), vanadium (7440622), arsenic (7440382), respirable free silica (14808607), and respirable quartz (14808607). Radon (10043922) gas samples were also measured. One of the factories exceeded the OSHA standards for fluoride concentrations, with an average concentration of 3.39 milligrams per cubic meter (mg/m3). Another factory exceeded the OSHA standards for arsenic, vanadium, and respirable silica. The concentrations of these substances at this factory were 0.08, 0.08, and 0.195mg/m3, respectively. Total chromium concentrations ranged from 0.001 to 0.008mg/m3. This was below OSHA standards but at or above NIOSH recommended standards of 0.001mg/m3 for carcinogenic chromium-VI. All other measurements at the four factories were below applicable OSHA standards. At the phosphate-ore mining facility, concentrations of uranium, arsenic, respirable silica, and respirable dust exceeded either OSHA or NIOSH standards. The concentrations for these substances were 0.228, 0.003, 0.07, and 1.62mg/m3, respectively. Of 19 samples collected, 2 showed detectable concentrations of radon daughters but were below exposure standards. The author concludes that the survey identified potentially hazardous substances in this industry. They recommend additional investigations be conducted on employee exposure to arsenic, chromium, and silica, and suggest an aggressive program of respiratory protection.
Division of Surveillance, Hazard Evaluations and Field Studies, NIOSH, Cincinnati, Ohio, Industrial Hygiene Survey Report No. 57-05, 44 pages, 11 references