Inhalational lung injury should be considered in patients presenting with acute respiratory symptoms and a history of occupational or recreational exposure to toxic substances. We present the case of a 29-year-old patient who developed pneumonitis following usage of waterproofing sealant spray in an enclosed space, despite the use of a dust mask. The patient was managed with oxygen therapy, corticosteroids and bronchodilators. He made a complete clinical recovery with resolution of almost all changes seen on computerised tomography (CT) imaging within 7 days.