Death due to Asthma at Workplace in a Diphenylmethane Diisocyanate-Sensitized Subject

Abstract

Total cases of fatal asthma in the occupational setting reported in the literature are reviewed and the case of a 39-year-old foundry worker who died at work is described. A diagnosis of occupational asthma induced by diphenylmethane diisocyanate (MDI) had been assessed 5 years in advance through a 0.005-ppm exposure inhalation challenge. Postmortem microscopic examination of the lung showed epithelial desquamation, eosinophilic/neutrophilic infiltration of the mucosa, dilatation of bronchial vessels, edema, hypertrophy and disarray of smooth muscle. Fatal asthma attack in a MDI-sensitized individual, to our knowledge, has not been previously described.

Preliminary report of mortality among workers compensated for work-related asthma

“…Fatalities have been associated with a worker sensitized to toluene diisocyanate (TDI) and more recently to methylene bisphenyl diisocyanate (MDI) [Carino et al, 1997], in both cases following re-exposure of previously sensitized subjects. Ehrlich [1994] described a baker with severe flour hypersensitivity who refused advice to give up his job, had severe exacerbations of his asthma, and then was found dead one day after returning home from work wheezing.…”

Diagnosis and prevention of diseases induced by isocyanate

“…Once a worker is sensitized, the only safe course is to remove them from the exposure. In very few cases, death may occur when sensitized patients continue to be exposed to the diisocyanate (3,4). Even wearing masks is not sufficient protection especially for sensitized patients.…”

“…In extremely rare cases, particularly with individuals who have previously become sensitized to isocyanates, the effects may be life-threatening (3,4). Long lasting respiratory effects may develop following repeated exposure to these isocyanates above the standard levels.…”

4,4′‐Methylene diphenyl diisocyanate (MDI) [101‐68‐8] and “polymeric” MDI (PMDI) [9016‐87‐9] [MAK Value Documentation, 2008]

“…Bronchial asthma is known to be a pathological condition induced by diisocyanates such as MDI (see supplement "4,4′-Methylene diphenyl diisocyanate (MDI) and "polymeric" MDI (PMDI)" 2000; Carino et al 1997;EU 2005;Perfetti et al 2003). On adherence to a PMDI concentration of below 5 ppb (0.05 mg/m 3 ), the new development of asthma attacks or asthmatic complaints was not observed (see documentation "4,4′-Methylene diphenyl diisocyanate (MDI) and "polymeric" MDI (PMDI)" 1997).…”