Abstract: The owner and Employee #1 were cleaning and buffing a tile floor with a propane-powered buffing machine. The main section of the facility was 30-ft by 12-ft. There was also an office, which was 8-ft by 11-ft. The ceiling height was 8 ft and 8-in. The owner and Employee #1 were found laying on the floor, unconscious, by a coworker. The coworker and his son summoned emergency medical services and pulled the owner and Employee #1 out of the facility. Fire department personnel responded and entered the building after it was ventilated for a short time and obtained carbon monoxide levels of 1,000 ppm. The owner and Employee #1 were transported to the hospital by EMS. Hospital records indicated that they suffered from carbon monoxide poisoning. Employee #1's blood was drawn approximately 30 minutes after leaving the scene and after having 100 oxygen administered. His carboxyhemoglobin level was found to be 41. The owner and Employee #1 were transported to another hospital for hyperbaric oxygen therapy. After being released, the employer had the emissions from the buffer tested and testing indicated carbon monoxide levels greater than 2,000 ppm.