New aspects of isocyanate asthma.

Air concentration of isocyanates are associated with the frequency of induced diseases. Asthma, bronchitis and rhinitis, chronic obstructive lung disease, and allergic alveolitis, respectively, were observed in exposed workers. Inhalation challenge tests with isocyanates found some 14% of symptomatic persons immunologically sensitized. At and above current threshold limit values (10 ppb) there is a risk of lung function deterioration also in asymptomatic workers.