Abstract: At approximately 4:00 p.m. on September 13, 2004, Employee #1, the site supervisor at a child care center, was removing paint stains from the floor with a spray bottle of liquid comet that contained bleach and a scrubbing pad. A coworker was mopping the floor using an unknown strength of ammonia solution. Natural ventilation was provided by leaving all doors and windows open. After removing the stains, Employee #1 dropped the scrubbing pad into the bucket of mopping solution. She was then hit by a strong smell which was most likely chlorine gas. Approximately 10 hours after her exposure, Employee #1 started coughing. She went to the hospital the next morning and was diagnosed with an acute lung injury. She was hospitalized for 4 days.