24 June 2006

Vacum Truck Thermal Burns

Safety Incident Topic : Thermal Burns To Operator
Location Of Incident : Toledo Refinery, United States
Date Of Incident : 25 May, 2006

Brief Account Of Incident
A Vacuum Truck Operator at Toledo Refinery received significant second degree burns while preparing to offload hot water to a sump. The employee was transported by Life Flight to a hospital for treatment.The investigation team was not able to interview the injured employee. OSHA opened a formal investigation related to the incident that remains on-going at the time of this report.

Onyx Industrial Services provides routine vacuum truck and pressure washing services to the refinery. The vacuum tank is fitted with an intake (vacuum valve) and discharge valve. Valves are four-inch, 1/4 turn ball valves with four inch camlock tailpieces. The operator was using a three inch hose for vacuuming (filling the tank) and another three-inch hose at the discharge sump. The intake valve on this truck fitted with a four-to-three inch reducer on the tail-piece to allow connection of a three-inch hose with camlock coupling.

After the incident, BP and Onyx inspected the vacuum truck. The vacuum truck was approximately ¾ full and the discharge valve was not leaking. The first person to arrive on-scene after the incident observed the discharge valve wide open, and a four-inch dust cap on the ground. The vacuum valve was closed, with the reducer, and dust cap installed. Manufacturer literature advises dust caps are not intended to contain hazardous materials or pressure.The injured had completed a Job Safety Analysis the day of the incident. He was wearing fire retardant clothing, safety glasses, hard hat, work boots and gloves.

What Went Wrong (Critical factors)
The injured either failed to notice the discharge valve was open during inspection, or opened the discharge valve before removing the four inch dust cap. The employee was positioned immediately behind the truck. As he removed the four-inch dust cap, he was exposed to the released contents of the vacuum truck.

Critical factors:
CF1: the technician removed cap from the discharge tailpiece of the vacuum truck while the discharge valve was in an open position
CF2: an inadequately protected technician burned from contact with hot water (estimated at 150 degrees or greater)

Possible Immediate Causes
- Unintentional error, improperly prepared equipment·
- Inadequate protective equipmentPossible System Causes·
- Inappropriate course of action (steps to offload truck)· Identification of worksite hazard (hot fluid, dust cap use, PPE)·
- Identifation of critical safe behaviours·
- Method of verifying absence of hot water behind cap

Key Learnings (addressed by actions)
1· Do you positively verify absence of thermal hazards before removing caps, plugs or valves from fixed andmobile equipment?
2· What safeguards are in place to manage fluids at temperatures >120degree F? (second degree burns occurwith exposure to hot fluids in five seconds at 140 degress F and one second at temperatures of 158 degrees F)
3· Is your equipment and that of your contactors designed to minimize the consequences of human error?
4· What PPE is required when transferring hot fluids?
5· How do you verify that contractors are conforming to their written HSE Plans (e.g equipment inspection, training, procedures, assesment)?

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