Reactive airway dysfunction syndrome, a type of occupational asthma without a latency period, is induced by irritating vapour, fumes or smoke. The present report is the first to describe a case of reactive airway dysfunction syndrome caused by acute exposure to dishwater detergent containing sodium metasilicate and sodium dichloroisocyanurate. The diagnosis was based on exposure data, clinical symptoms and signs, as well as respiratory function tests. A 43-year-old nonatopic male apprentice cook developed respiratory symptoms immediately after exposure to a cloud of detergent powder that was made airborne by vigorous shaking of the package. In spirometry, combined obstructive and restrictive ventilatory impairment developed, and the histamine challenge test revealed bronchial hyper-responsiveness. Even routine handling of a strongly caustic detergent, such as filling a dishwasher container, is not entirely risk free and should be performed with caution.