Accident: 201030673 - Nine Exposed To Benzene

On February 14, 1997, during the shutdown/turnaround period for an unsaturated gas plant, Delta Tech, the contractor, completed a water/chemical wash of debutanizer tower 8C-6 and heat exchanger 8E-39. At approximately 8:05 a.m. on February 15, 1997, Employee #1 was requested by the control room of the unsaturated gas plant to drain any water/chemical residues from heat exchanger 8E-39. Employee #1 drained the material through the heat exchanger's bottom drain valve into the refinery's sewer. As the residue was released, it changed into gasoline. Once the supervisor took notice of the gasoline, he attempted to close the bottom drain valve. The valve bushing broke and Employee #1 notified maintenance that assistance was needed to close the valve. Maintenance responded by putting in a sipe valve and tapping it into packing. Mobil's fire brigade and its safety and emergency response team brigade were notified and barricade the immediate area around the debutanizer and heat exchanger. Industrial hygienists monitored the perimeter and sewer system for benzene, with results indicating levels between 1.9 and 11.6 benzene. Employees #1 through #9 were taken to a medical clinic for benzene testing. Urinary phenol evaluations indicated levels that did not require additional testing.

benzene, chemical, overexposure, chemical reaction, inhalation, work rules, toxic atmosphere, chemical vapor, air contamination, toxic fumes

Accident: 170620512 - No Employees Injured In Accidental Hydrocarbon Release

At the gasoline blending unit of an oil refinery, a new product lineup was performed and the equipment was started. Overpressure developed in the product line and was relieved through a pressure relief system, but it was unable to contain the hydrocarbon volume with associated loss of containment. Seventy-three employees were tested for benzene exposure, with 72 negatives and one false positive. The predominant factor leading to the incident resulted from a temperature increase with pressure increase in the downstream body of a twin seal valve, causing the guide pin to shear upon opening. The valve appeared to be open but was closed.

gas leak, valve, gas, benzene, high pressure, equipment failure, pin, sheared

Accident: 14372064 - Splashed With Chemical During Spill

At 12:45 a.m. on April 16, 1992, Employee #1 was performing fluoride tests on a lab top when a still containing a maximum of 250 mils of Ethyl Benzene/Benzene, 100:1 developed a leak. The chemical mixture was emitted, then ignited and exploded when it contacted a hot surface. The liquid mixture, used to determine total fluoride in samples, splashed onto the employee's wrist causing redness.

spill, wrist, explosion, benzene, chemical

Accident: 170175525 - Exposed To Spilled Benzene

At approximately 1:20 p.m. on October 8, 1991, Employee #1, of Stanford University, was attempting to return a 4 liter bottle of benzene to a storage area when the bottom of the bottle struck another bottle and broke. Employee #1 asked several coworkers to notify the health and safety department, then proceeded to clean up the spill unprotected by a respirator or gloves. Employee #1 remained in the area for three to five minutes after other employees had evacuated. He was sent to Palo Alto Medical Clinic for testing, but was not hospitalized. The Stanford Environmental Health and Safety Emergency Response Team arrived at about 1:30 p.m. and cleaned up the spill. At 12:00 noon on October 9, 1991, an industrial hygienist at Stanford University reported the incident to the San Mateo District office.

benzene, work rules, inhalation, evacuation, respirator, glove, spill, elderly, ppe, emergency response

Accident: 170172845 - Exposed To Benzene

At approximately 3:00 p.m. on April 3, 1991, Employee #1, of Stanford University, was removing a 1-gallon bottle of benzene from the back of a shelf for a chemist who was waiting outside the storage area. Employee #1 was having difficulty because other items were in front of the bottle. When the bottle struck the shelf's retaining lip, it broke. Employee #1 was exposed to benzene vapors and remained in the storage room for approximately 5 minutes, at which time the chemist told him to leave the area.

work rules, benzene, housekeeping, overexposure, toxic fumes, storage area, chemical vapor, vapor, inhalation, chemical