Health and environmental effects profile for pentachloronitrobenzene

Pure pentachloronitrobenzene (PCNB) is a colorless crystalline solid (Worthing, 1983). The commercial product may have a light-yellow to cream color with a musty odor (Hartley and Kidd, 1983). It is practically insoluble in a number of organic solvents. The compound is reasonably stable but may undergo hydrolysis in a strong alkaline medium (Hartley and Kidd, 1983). In 1983, Olin Corp., Leland, MS, was the only manufacturer of PCNB in the United States (SRI, 1984; Hartley and Kidd, 1983). No data for U.S. production volume for this chemical are available, but recent production source data (USITC, 1985; SRI, 1985) suggest that this chemical is no longer commercially produced in the United States. The primary usage of PCNB is as a soil fungicide for a wide variety of crops and in seed treatment (Worthing, 1983; Hartley and Kidd, 1983). The fate of PCNB in water has not been comprehensively studied. Only qualitative data regarding fate and transport in water are available. The half-life of PCNB in the water phase was estimated to be 1.8 days. The two processes reported to be most responsible for the rapid decrease in PCNB concentration in water were volatilization and sorption to seston and biota, followed by sedimentation as detritus (Schauerte et al., 1982). Neither biodegradation nor photolysis appears to be a significant process for the loss of PCNB from water (Crosby and Hamadmad, 1971; Schauerte et al., 1982). The BCFs for PCNB in the golden orfe, Leucisens idus melanotus, and in rainbow trout, Salmo gairdneri, were reported to be 950-1130 and 260-590, respectively (Korte et al., 1978; Oliver and Niimi, 1985). It therefore appears that PCNB will moderately bioaccumulate in aquatic organisms. Pertinent data regarding the fate and transport of PCNB in air could not be located in the available literature as cited in the Appendix. Based on its physical properties and its behavior in other media, it would appear that PCNB will persist in the atmosphere because no known chemical/photochemical processes significantly degrade this chemical. Precipitation of particulate PCNB, especially of larger particle size and higher particle density, may remove some PCNB from the atmosphere. PCNB is persistent in soils. The two processes that are important in the loss of PCNB from soils are volatilization and biodegradation; biodegradation is more rapid in soils under anaerobic conditions than under aerobic conditions (Ko and Farley, 1969; Casley, 1968; Gile and Gillett, 1979; Cole and Metcalf, 1977).(ABSTRACT TRUNCATED AT 400 WORDS)