Dioxin Registry report for Thompson Chemical Company, St. Louis, Missouri

An industrial hygiene survey was conducted at the Thompson Chemical Company, St. Louis, Missouri. The company manufactured sodium-2,4,5-trichlorophenate (NaTCP), 2,4,5-trichlorophenoxyacetic-acid (2,4,5-T), and esters and amines of 2,4,5-T from 1949 through 1970. The company manufactured Agent-Orange for the Air Force from 1967 until 1969. The facility, its processes, its workforce, and 2,3,7,8-tetrachlorodibenzo-p-dioxin (1746016) (TCDD) analytical results for these products were examined. As this firm filed for bankruptcy in 1970, there was only limited data available. The facility employed about 12 persons year round and about double this number during the busy season and during the Agent-Orange contract. Almost no information was available about the production processes. Nine persons developed chloracne after an accident and fire in the NaTCP process. Few personnel records were available. The authors conclude that workers employed from 1949 through 1970 are suitable for inclusion into the Dioxin Registry. There is not enough information available to construct a TCDD exposure matrix for this site.