Abstract: At approximately 9:00 a.m. on July 28, 1995, operators at the All Pure Chemical Co. observed a cloud of chlorine gas seeping from the top opening of a 4,000 gallon bleach batch tank. Two operators attempted to suppress the chlorine cloud. They checked and closed the valves from a railroad tanker's "gas off" line, applied water in the direction of the tank opening, added 50 percent caustic to bleach batch tank #2, and shut off the failed caustic pump. In the meantime, the remaining employees notified the proper authorities and stayed upwind from bleach batch tank #2. The cloud drifted in a northwest direction, exposing 34 employees at Crockett Container. At approximately 9:12 a.m., the Santa Fe Springs Fire Department arrived and monitored the actions at All Pure Chemical Co. They also set up a triage center at Crockett Container, where Employees #1 through #34 were treated for chlorine exposure. Eighteen of these employees were sent to the local hospital for further evaluation and medical treatment. No employees of All Pure Chemical Co. were injured.