Five patients became short of breath following the use of a waterproofing spray in an unventilated room: one 40-year-old woman and 4 men aged 40, 18, 21 and 39 years, respectively. After treatment the complaints diminished within the course of a few weeks. Waterproofing sprays are commonly used to make clothing and shoes water-repellent. Several hours after inhalation of such sprays symptoms of dyspnoea can occur. Without therapy this can lead to pulmonary fibrosis. Corticosteroid therapy seems to shorten the duration of complaints in the acute phase and preclude fibrosis. It is therefore advisable to present patients with respiratory complaints following inhalation of waterproofing sprays at an emergency department. A chest X-ray and blood gas analysis should be performed. In case of abnormalities, patients should be hospitalised.