Isocyanates account for the highest number of reported cases of occupational asthma in the United States and developed countries. Prevention, however is limited by inadequate knowledge of isocyanate routes of exposure, exposure patterns, mechanisms of sensitization and other causal factors. The Survey of Painters and Repairers of Auto Bodies by Yale (SPRAY), a five-year cross-sectional epidemiologic survey of painters and repairers of autobodies at Yale was therefore initiated to address these questions. At the outset of Spray, it was not known how frequent skin contact among the painters might be. Moreover, there is new and exciting data from animal studies demonstrating that dermal rather than respiratory contact may be crucial to immune sensitization leading to asthma. Little is known, so far, about dermal exposure in autobody shops and its modifiers, especially the effectiveness of personal protective equipment (PPE) in preventing workers from skin contamination by isocyanates.