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Isocyanates are the most prominent and well-studied cause of occupational asthma. Over the decades, airborne isocyanates have been regulated to extremely low levels in the workplace, some of the lowest for any organic compound. Yet the incidence of isocyanate-induced occupational asthma remains high and the role of dermal exposure in disease etiology is only slowly being recognized. Almost completely overlooked is the potential relationship between isocyanates in consumer products and increasing prevalence of asthma in the general population, especially children. The steady rise in asthma over the past decades points strongly to a potential role of environmental exposures in its development. Imbalances in the immune system favoring respiratory diseases have been linked to biological and chemical stressor exposures early in life. Evidence for the presence of isocyanates in many polyurethane-containing materials, especially polyurethane foams, is presented as a possible contributor to the increase in asthma. Polyurethane foam is ubiquitous in western societies and used in bedding, furniture, automobile seats, footwear, etc., and numerous medical materials. Theoretical, epidemiologic, experimental and clinical evidence of a role for isocyanates and polyurethanes in the genesis of non-occupational allergy and respiratory disease are reviewed. These data all point to the urgent need for additional research on the links between isocyanates, polyurethanes and the role of the skin in non-occupational asthma.

Wearing chemical-resistant gloves and clothing is the primary method used to prevent skin exposure to toxic chemicals in the workplace. The process for selecting gloves is usually based on manufacturers' laboratory-generated chemical permeation data. However, such data may not reflect conditions in the workplace where many variables are encountered (e.g., elevated temperature, flexing, pressure, and product variation between suppliers). Thus, the reliance on this selection process is questionable. Variables that may influence the performance of chemical-resistant gloves are identified and discussed. Passive dermal monitoring is recommended to evaluate glove performance under actual-use conditions and can bridge the gap between laboratory data and real-world performance.

Issuing gloves to workers is the most common approach to protecting against skin contact with hazardous chemicals. Typically, glove materials are selected and duration of wear is estimated based on comparisons of laboratory test data. Those who select the glove materials often fail to verify their selections by testing the glove during actual use. This failure poses a common but potentially serious hazard to workers. Although methods are available for assessing permeation rates during actual use, such testing is unlikely without acceptable exposure guidance criteria for decision making. This document reviews methods for testing glove performance during actual use and suggests an approach for estimating acceptable exposure guidance criteria for evaluation of chemicals that are systemically absorbed. It is the authors' opinion that as of now an approach to estimating exposure criteria for chemical irritants and sensitizers may not be feasible. With available data resources, acceptable glove exposure criteria could be generated for use in assessing the risk of using specific gloves for handling many compounds in occupational settings.

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