Objectives Exposure to metalworking fluids is known to cause mucous membrane inflammation of the airways. In this case report, the authors attempted to identify responsible components in the metalworking fluids for the rhinitis of an exposed patient.

Methods The patient underwent two provocation tests. The first provocation was performed with the different metalworking fluids used in the factory, and the second was done double blind for some of the components in the metalworking fluids. The patient was asked to quantify her symptoms before, immediately after, 24 hours after, and finally 96 hours after the exposure.

Results The patient reacted to tolyltriazole with rhinitis and headache. These symptoms started about 8 hours after the exposure and persisted for 24 hours.

Conclusion The double-blind provocation exposure to the components of the metalworking fluids showed that the patient reacted to the corrosion inhibitor tolyltriazole. To the authors’ knowledge, no such reaction to tolyltriazole in the airways has previously been reported.

Key terms benzotriazole; case report; metalworking fluid; occupational rhinitis; rhinitis; tolyltriazole