Occupational asthma due to tetrachlorophthalic anhydride

The plastics industry utilizes a number of organic chemicals which have the potential of producing pulmonary reactions, particularly in susceptible individuals. Five workers are reported who were involved in the production of epoxy resins and developed recurrent respiratory symptoms and physiologic abnormalities following exposure to tetrachlorophthalic anhydride (TCPA). Inhalation challenge with TCPA reproduced their symptoms and demonstrated both an immediate and late (4-6 hours) physiologic response. Although the clinical picture strongly suggested a hypersensitivity reaction, immunologic studies failed to demonstrate precipitating or specific IgE antibody. Avoidance of exposure resulted in resolution of symptoms; however, three of the five individuals had residual functional impairment.