[The isocyanates: respiratory pathology]

Isocyanates are often used in making polyurethanes (foam, varnish, paint, glue). They interest allergists and work physicians. Effects are different according to concentration. In strong concentration they are irritant. In weak concentration they bring on asthma. A long exposure may provoke chronic airway obstruction. Diagnosis is not easy, based on clinical, physiologic and laboratory characteristics. Mechanism is unknown (immunological, irritant, beta-blocking effect).