Case studies

This page contains case studies covering some of the main causes of injury and work-related ill health in the surface engineering industries. These are real incidents and often with serious consequences for those involved.

Exposure to or contact with harmful or hot substance or object

• A self-employed electroplater died from hydrogen cyanide released from a waste products bath. It is believed that the solutions were being treated for disposal but the pH was not controlled adequately allowing generation of the poisonous gas.
• A partner in a small finishing company was fatally injured when he fell into an open-topped 1m3 tank containing sodium hydroxide at 90C. He had been helping to lift a heavy item suspended by a wire from a wooden beam into the tank when he fell and was completely immersed in the solution. The vertical distance between the raised walkway and the top of the tank was only 730mm but the main cause of the fatality was the unsafe system of work.
• An employee received severe burns to the legs after falling into a caustic cleaning tank solution at 80C. He was cleaning an electrode on the far side of the tank and walked along the edges of the vessel before losing balance and falling in up to the waist. Although a transporter and walkway were available it was rarely used and supervisors also walked along the tanks.
• A paint sprayer suffered blistering of his face and hands after using 2-pack epoxy paint. The operator had no gloves and was using a 'nuisance' dust mask. Following the incident an air-fed helmet and appropriate gloves were used and the product applied by brush.
• The director of a small powder coating company was found dead in a trichloroethylene vapour-degreasing tank. His employee described how the director had previously entered the tank to clean out the waste until he felt 'unwell'. He would then climb out, get fresh air and then go back in to continue the operation. In the past 7 years, nearly a third of all fatalities in the surface engineering industry have been from exposure to chlorinated hydrocarbons.
• Spillage of titanium tetrachloride occurred when a heat treatment furnace was been serviced by the European manufacturer. The engineer spoke little English, was not wearing appropriate PPE and was unaware of correct emergency procedures. By applying water to the spillage, he increased the amount of hydrogen chloride generated. The extractor fan was turned on, exhausting the fume into in the yard of a neighbouring firm during a break time resulting in sixty-six people being taken to hospital.

Fires and explosions

• A paint sprayer was cleaning his electrostatic spray system with waste gun wash. The wash can was not earthed and a spark ignited the flammable vapour. 25l of waste thinners exploded, engulfing the employee who received 40-50% burns to the lower body.
• An employee was asked to burn off paint residue on conveyor hooks from a powder coating line. Using the established method, he placed the hooks in a can and he filled it with waste thinners from a container. He lit waste paper and put it in the can and walked away carrying the container of thinners. Noticing flame coming from the thinners container he went to throw it away but it erupted in flame, knocking him to the floor. When he came to his arms and hands were alight and he suffered extensive burns.
• A polypropylene tank had been emptied of liquid for cleaning. It ignited after an automatic timer switched on heaters at night. It is believed that the timer was advanced by one cycle in error rather than being switched off.
• A fire occurred at a trichloroethylene vapour-degreasing tank when the solvent level fell to such an extent that the accumulated grease/oil overheated. The low solvent level indicator was defective so the operator, who had left the tank unattended, was unaware that manual topping up was required. In a similar incident a fire occurred when the solvent was rapidly sucked through the extraction system after a makeshift lid was placed over the top of the tank, above the extraction slots (the lid should fit on a lip just below the extraction vents).
  

More information on fire and explosion

Falls from height

• A walkway above a galvanizing rinse tank collapsed causing an employee to fall about 2.6 metres. He was fortunate to sustain only severe bruising. The walkway consisted of crosswise timbers supported by L-section metalwork welded to the tank sides. The supports were only 3 years old but failed due to corrosion. The rinse tanks only contained a dilute acidic solution but it is important to remember that dilute acid can be more corrosive than when concentrated.
• An electroplating lab technician used an unsecured ladder to gain access to a mezzanine floor. When near the top, the ladder slipped out causing her to fall some 2 metres to the floor fracturing her heel. The ladder was found to have a defective floor grip. The case demonstrates the importance of maintenance but, more particularly, that access between floors should not normally be by way of ladders or steep stairs.
• During maintenance work on the top of an overhead travelling crane a contractor fell through part of the fume extraction canopy suspended from the crane into a tank of molten zinc. He died from his injuries. There were no written instructions and a permit to Work system was in place but not used. Two Safe Working Procedures requiring the use of harnesses were in place but the contractor was not wearing a harness when he fell to his death.

More information on falls from height

Workplace transport

• A forklift truck (FLT) operator was loading a lorry. He stopped on an incline in front of the lorry with the FLT engine running and the parking brake applied. He stood with his back to the FLT, which crept down the hill and crushed him against the lorry. He died from his injuries.
• An office worker walked round a corner and failed to see a reversing FLT carrying a load. The driver shouted a warning but was unable to stop in time. The office worker was knocked to the floor striking her head and suffering a fractured back. Noise from process and nearby road would have made the electric truck inaudible. After the accident the company fitted a reversing light and alarm to the FLT but segregation of pedestrian and vehicle movements is the primary safeguard when considering transport safety

More information on workplace transport

Slips and trips

• Walking past the decoiler-end of the plating lines, an employee slipped on a discarded plastic corner piece. The bin provided had not been used. He fell, lacerating his leg on steel coil lying on the floor.
• An employee slipped while descending 2 steps on the side of a rinse tank. Although known to get wet, the steps were made from standard floor plate. The employee dislocated his shoulder and was off work for a significant period.

Further information on slips and trips

Struck by

• An employee was moving a large, newly painted object into a drying oven. It was not secured to the trolley and fell off hitting the employee. He sustained fractured ribs and injuries to his leg and head. An overhead hoist was installed in the factory but could not reach the drying area.
• An employee lost the sight of an eye when he was hit by a piece of swarf. He was using a compressed airline to clean metal cabinets prior to powder coating but without eye protection. Inadequate consideration had been given to safer alternatives eg vacuuming.
• Whilst refurbishing a large crankshaft prior to recoating, a grinding wheel failed catastrophically. Part of the wheel struck the operators head, fatally injuring him. The crankshaft was set up in conventional lathe, and the bearings were to be reground using an attachment mounted on the lathe saddle. The maximum safe operating speed was marked on wheel but there was no indication of speed of grinding attachment and no means of adjusting the attachments to a safe speed. The wheel burst because it was used at over twice its safe operating speed. No guard was fitted to grinding attachment (to contain a wheel burst or to protect operator from contact with the wheel) and the lathe controls required the operator to be close to wheel.