Summary of recent environmental assessments of exposure to grain fumigants at export, inland, and country elevators.
Principles of health and safety in agriculture. Dosman JA, Cockcroft DW, eds., Boca Raton, FL: CRC Press, Inc., 1989 Oct; :240-243
The results of NIOSH environmental assessments of exposure to grain fumigants at export, inland, and country elevators were discussed. The studies consisted of health hazard evaluations (HHEs) of 80/20- liquid-fumigant (80/20LF), an 80:20 mixture of carbon-disulfide (75150) and carbon-tetrachloride (56235); ethylene-dibromide (106934); methyl-bromide (74839); phosphine (7803512); malathion (121755); chloroform (67663); ethylene-dichloride (107062); and 1,2- dichloroethane (107062) exposures at grain terminals in Portland, Oregon, New Orleans, Texas, and in the Great Lakes region. An industrywide survey was conducted of exposures to a liquid malathion/methoxychlor (72435) mixture and phosphine generated by aluminum-phosphide (20859738) tablets in grain elevators. Full shift samples were generally obtained to evaluate exposures relative to time weighted average (TWA) OSHA permissible exposure levels (PELs), NIOSH recommended standards, and American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit values (TLVs). Some short time samples were also obtained to evaluate peak exposures during certain cycles of work activity. The HHEs indicated that fumigant exposures were generally low. For example, carbon- tetrachloride exposures varied from nondetectable to 1,200 micrograms per cubic meter (microg/m3), well below the NIOSH standard and OSHA PEL of 12,000 and 62,000microg/m3, respectively. Carbon-tetrachloride and carbon-disulfide exposures originating from use of 80/20LF were generally below the OSHA PEL, but frequently exceeded the NIOSH standard, the standards for carbon-disulfide being 62,000 and 3,000microg/m3, respectively. Representative short term carbon-tetrachloride and carbon-disulfide exposures measured during a 10 minute fumigation operation varied from 265 to 378 and 60 to 132mg/m3, respectively. Phosphine exposures measured during fumigation with aluminum-phosphide tablets ranged from below 0.02 to 2.2mg/m3. The TWA ACGIH TLV and OSHA PEL were both 0.4mg/m3. No excessive malathion or methoxychlor exposures were detected. The authors conclude that exposure to grain fumigants in the studied operations are generally low. Some excessive 80/20LF and phosphine exposures do occur. Appropriate engineering controls and use of protective equipment to reduce these are recommended.