An Acute, Time-Weighted Exposure of Hexamethylene Diisocyanate (HDI) and the HDI-Ethanol Urethane Monomer, Hexamethylene BIS (Ethyl Carbamate) (HDC).

Download or read book An Acute, Time-Weighted Exposure of Hexamethylene Diisocyanate (HDI) and the HDI-Ethanol Urethane Monomer, Hexamethylene BIS (Ethyl Carbamate) (HDC). written by Ray Smith and published by . This book was released on 1998 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hexamethylene diisocyanate (HDI) is a compound that is condensed with a diol or triol to form polyurethanes, which form the structural matrix of some industrial paints. HDI is readily used in high-performance paints such as those used to protect aircraft, and is easily released (mechanically) during industrial painting operations. Like other isocyanates, HDI is believed to cause occupational asthma via a type-I hypersensitive reaction in the lung epithelium. Since no satisfactory correlation has been established between the maximum allowable time-weighted average based on an eight-hour standard and the actual concentration of HDI present in most aircraft paint formulations, the immunologic effects of polyurethanes formed from isocyanates, if any, are less severe than those caused by HDI. This study consisted of a time-weighted, in vivo, subchronic, whole-body inhalation study on adult male Sprague-Dawley rats. Since the effects of a HDC were less than HDI, this study provided a better understanding of some of the toxicological impacts of HDI versus its proposed regulatory limits.