Occupational asthma caused by a plastics blowing agent, azodicarbonamide

A prevalence study of occupational asthma was carried out by questionnaire in 1980 among a group of 151 workers who had been exposed to azodicarbonamide dust in the process of its manufacture. Twenty-eight (18.5%) people without previous asthma gave a history of episodes of late onset asthma after exposure to azodicarbonamide. Re-exposure caused repetition and worsening of symptoms. Immediate removal from further exposure resulted in rapid cessation of symptoms without further recurrence. Seven of 13 sensitised individuals who were still exposed three months after the onset of disease developed prolonged airways hyperreactivity to common environmental irritants. Azodicarbonamide should be excluded as a causative agent in plastics and rubber industry workers complaining of occupational asthma.