Abstract: At 12:45 p.m. on July 16, 2019, an employee was prepping an upstairs bathtub for refinishing by chipping and sanding, taping the polyethylene film roll and removing old caulk. The bathroom was approximately 263 square feet and leasing occupants were present downstairs so the employee kept the bathroom door closed during his work. The employee wore the required tight-fitting 3M Series 7503 CoolFlow half-face elastomeric air-purifying respirator with 3M 6001 organic vapor (OV) cartridges and voluntarily wore latex gloves, but did not wear eye protection. The employee stated that he used the bathroom exhaust fan instead of the employer provided portable ventilation system. After prepping, the employee began to spray the bathtub tiles with Midwest Chemical Aerospace Primer, Part A, and Midwest Chemical Aerospace Primer, Part B, category 2 flammable liquids, with the use of an electric Titan Capspray 75 High-Volume Low-Pressure (HVLP) finishing sprayer in conjunction with a Titan Maxum II Pressure Fed Gun fine finishing sprayer situated within the bathroom. After primer application, the employee began spraying Midwest Chemical PE 1000 Urethane Catalyst, and Midwest Chemical PE 1000, Part A, onto the bathtub with the use of an electric Titan Capspray 75 HVLP in conjunction with a Titan Maxum II Pressure Fed Gun, still located within the bathroom space, with the bathroom door still shut closed. The employee noticed a fire likely generated from the Titan Capspray 75 and the employee attempted to exit through the bathroom door. The employee was only capable of making it roughly two-thirds of the way before he was caught in an explosion. After the explosion occurred, the employee ran downstairs to inform all occupants that they needed to evacuate and everyone escaped through the back door of the residence. The employee sustained chemical burns over thirty percent of his body including his lower arms, face, back, chest and lower legs and was hospitalized.