Respiratory diseases caused by occupational exposure to 1,5-naphthalene-diisocyanate (NDI): Results of workplace-related challenge tests and antibody analyses.

BACKGROUND

1,5-naphthalene-diisocyanate (NDI) is an aromatic diisocyanate with a very low vapor pressure which is mainly used in the automotive industry.

METHODS

In the present study we described five cases with workplace-related asthma and one case with extrinsic allergic alveolitis associated with pulmonary hemorrhage after NDI exposure.

RESULTS

Corresponding to case histories, extrinsic alveolitis on asthmatic reactions in three subjects and a rhinitis reaction in one patient could be reproduced by inhalative challenge tests to NDI at a concentration of 10 ppb. Preliminary IgE and IgG antibody analyses in patients' sera did not produce significantly positive results.

CONCLUSIONS

According to the outcome of our tests and in comparison with several other studies, we conclude that NDI should be classified as potent airway-sensitizing substance. Improved workplace conditions and decrease in threshold limit values should therefore be recommended.