Inspection Detail

Inspection: 310811666 - Prudential Overall Supply

Inspection Information - Office: San Diego District Office

Investigation Summary

On May 11, 2007, an employee was changing out a pallet of drums in the hazardous materials storage area which contained chemicals that feed the lines to the industrial washing machines. The chemical normally used in the industrial washing machines was sodium hypochlorite (12 in. solution, which was stored in labeled blue drums in the hazardous materials storage area). Also located in the hazardous materials storage area were drums containing Sulfuric Acid, 93 in. solution, stored in labeled black drums and utilized in a separate area of the facility to lower the pH of wastewater prior to discharge to the sanitary sewer system. When the drums of sodium hypochlorite were empty, they were typically changed out with another pallet of drums. According to witnesses, the sulfuric acid drums were moved into place to feed the industrial wash lines instead of sodium hypochlorite, and the solution was then used to launder garments on May 10. The garments laundered had a distinct odor, and the mistake was noticed at about 6:00 p.m. on May 10. The employer stopped laundering garments until the following morning. On the morning of May 11, the chemical supplier was contacted regarding the proper way to flush the industrial wash lines and reintroduce the sodium hypochlorite to continue laundry operations. The employee was in charge of changing out the pallet of sulfuric acid drums, replacing them with sodium hypochlorite drums, and restarting the laundry process using the methods described by the chemical supplier. The chemical supplier advised the employee and managers to flush the sulfuric acid out of the feed lines using water, and then reintroduce the sodium hypochlorite solution. When the sodium hypochlorite was reintroduced to the feed lines, it reacted with approximately one quart of residual sulfuric acid which was still in the floor drain area near the industrial washing machines and produced chlorine gas which was vented to the main wash room. The chlorine gas was noticeable by the effect it had on nearby employees, who had respiratory distress, problems with their eyes, and caused workers to feel dizzy and nauseous. No alarms were sounded and the facility evacuation relied on word of mouth communication between workers. The facility was evacuated; however, some workers remained inside longer because they were uninformed of the evacuation and of the nature of the chlorine gas inside the building. At approximately 8:45 a.m., emergency services were notified and responded to the site. Twenty one employees were transported to local hospitals for evaluation and treatment; however, all employees were released the same day. Three employees were asked to return to the clinic the following week due to continuing symptoms that may have been associated with the chemical exposure.

Keywords: LUNG, SODIUM HYPOCHLORITE, INHALATION, SPILL, SULFURIC ACID, CHEMICAL