Abstract: At approximately 4:58 a.m. on July 23, 2008, Employees #1 - #12 were working at a Harris Teeter grocery store in Charlotte, NC. Employee #1 was using a propane fueled General Jet pressure washer which contained a 16 HP Vanguard Briggs and Stratton engine. He was cleaning a 4-in. drain with the pressure washer inside the produce preparation cooler, which did not have a ventilation system. He was overexposed to carbon monoxide and was found unresponsive. Emergency medical services were called. The Charlotte Fire Department responded and obtained Carbon monoxide readings ranging from 2 parts per million- in excess of 999 parts per million. The store was later evacuated, and the employees were transported to Carolinas Medical Center and Presbyterian Hospitals for medical evaluation and treatment for Carbon monoxide exposures. Employees #1 - #12 were not hospitalized. Employee #1 was exposed to concentration levels ranging from 224.57 ppm with a 8-Hour TWA of 166.56 ppm to 316.68 ppm with a 8-Hour TWA of 234.87 ppm. NOTE- the narrative says none of the employees were hospitalized but the injury lines state that one employee was hospitalized.