Specific aims included: 1) Qualitatively and quantitatively assessing surface and skin contamination of HDI; 2) Identifying modifiers that affected surface and skin contamination, and specifically evaluating the effectiveness of personal protective equipment in protecting the skin from isocyanate contamination; 3) Exploring the relationships of dermal exposure with airborne exposure, biomarkers of systemic absorption and skin sensitization, and asthma-developing risk.