Abstract: At approximately 11:50 a.m. on April 19, 2010, Employee #1, a communications technician, was assisting a vendor with questions about an installation. While sitting at the desk, Employee #1 began to feel dizzy and disoriented. A coworker noticed that Employee #1 looked a little flush and helped Employee #1 to exit the door and go outside to get some fresh air. While outside, Employee #1 continued to feel dizzy and disoriented and the coworker called 911 for medical assistance. Employee #1 was transported to John Muir Concord and was hospitalized more than 24 hours for observation only. Air quality measurements taken during the inspection noted no abnormal CO, LEL, H2S or O2 readings. The battery banks were electronically monitored for leak detection and monitoring records were requested for the date of the incident to check any possibility of exposure. No leak detection was noted on these records. At the time of the incident, Employee #1 had an ear infection and physicians determined that vertigo from the ear infection was the cause of the incident. Employee #1 was hospitalized for more than 24 hours for observation only and no environmental or other causal factors were noted during the investigation, therefore no regulatory actions shall be taken. The employer called the Concord Cal/OSHA office at approximately 9:37 a.m. on April 20, 2010 to report the incident. DOSH arrived at the location on April 28, 2010 to conduct an Accident Investigation.