luene diisocyanate (TDI) isease: Immunologic and inhalation challenge studies

Clinical and serologic effects of TDI exposure were studied in 112 occupationally exposed plant workers. Sera were obtained before and after commencement of TDI production. A11 subjects were skin-tested with common inhalant allergens and a TDI-HSA conju.gate. Total eosinophil counts, immunoglobuliw quantitatioas, fina specific antibody assays by PCA, P-E, and ~adioimmunoassay were performed. Clin,ioally “sensitive” i@vid~als were tested by provocative inhalation challenge with from 0.005 ppm to the threshold limit ?;a& of 0.08 ppm TDI. Bo TDI-induced immunologic changes were noted with the exception of 3 in~diviSuals who demo&rated small positive wheal-and-erythema reactions to TDI-HSA but not to HSA alone. Inhnlrction cha.llenge with, TDI vapor produced airways obstruction, as measured by FEF,,,_,,,. These responses were of the imm.edinte, delayed, and dual type, and were provoked in some cases with levels as low (1s 0.005 ppm TDI.