Dioxin registry report. Prepared by review of doucments received from Thompson-Hayward Chemical Company, Kansas City, Kansas, report no. IWS-117-12.
The National Institute for Occupational Safety and Health (NIOSH) Dioxin Registry is a compilation of demographic and work histories information for all U.S. production workers who have synthesized products known to be contaminated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) and/or hexachlorodibenzo-p-dioxins (HxCDD). Currently, there are fourteen production sites and approximately 7000 workers included in the Registry. The first use of this information will be for a retrospective cohort mortality study for which the comparison group is the U.S. male population. This study will evaluate the causes of death among the workers exposed to products contaminated with 2,3,7,8-TCDD and/or HxCDD. The Thompson-Hayward Chemical Company, in Kansas City, Kansas, is a site included in the Registry. Esters of 2,4,5-trich1orophenoxyacetic acid (2,4,5-T) and 2-(2,4,5-trichlorophenoxy)propionic acid (silvex) and some sodium 2,4,5-trich1orophenate (Na 2,4,5-TCP) were produced at this site from 1948 to 1959 and 1963 to 1977. 2,4,5-T formulation occurred from 1948 to 1978 with only limit formulation occurring from 1959 to 1963. Presented in this report is a description and history of the facilities, workforce, processes, past exposures and personnel record systems taken from company documents, and collected during site visits in 1981, 1982, and 1985.