Two employees at a company that was packaging sweet potatoes were using an oxygen-acetylene torch to loosen a fitting on an old fuel tank, which the company hoped to refurbish for field storage of diesel fuel. The workers, however, were unaware that the tank contained residual hydrocarbon liquid and vapor from an unknown prior use. The tank was not cleaned or purged before work began. Shortly after applying heat to the tank, an explosion occurred, blowing the end of the vessel off. Both employees were airlifted to a regional burn center, where they were treated for burns covering 30 to 50% of their bodies.
The facility had no formal hot work program, and no permit was issued for the hot work being performed. No combustible gas testing was performed prior to commencement of the hot work; the company did not have a policy that required it. In addition, many workers were mono-lingual Spanish speakers and had not been trained on safe hot work procedures or on the proper use of gas detectors in their native language (Source: Chemical Safety Board – USA)