This month we saw CAL-OSHA issue citations to a roofing company after two of its employees were literally blown off an asphalt tanker and ten (10) feet to the ground. Both workers sustained serious burns to large portions of their bodies. But after hearing all the comments about "safety is just common sense" I wonder how many professionals, including safety professionals, actually know that an asphalt tanker and kettles can and most often do contain a flammable atmopshere? One fact we do know, at least two workers and their supervisor were NOT aware of this hazard, as the two employees standing on top of a tanker truck were attempting to turn the truck’s discharge pipe to face another direction and their supervisor instructed them to heat the pipe with a propane torch in order to loosen it. The tanker was half-filled with hot liquid asphalt meaning there was plenty of vapor space in the tanker, coupled with the fact that heated liquid asphalt releases flammable vapors made for the perfect storm.
Back on March 4, 2016 a contractor/truck driver was transferring "diesel fuel" of some type from a storage tank to his truck when there was a flash fire. He received 2nd and 3rd degree burns over 50% of his body and has since passed away from his injuries. When I saw this incident in my Incident Alerts I was very curious as to how diesel fuel could be involved in a flash fire due to its HIGH flash point (~140F depending on grade of fuel). But as stated by the Asst. Chief of the responding FD, the material he was transferring was not all diesel and the solution had some flammable liquid mixed in...
Process or storage vessels and pipe systems that contain ignitable ranges of oxygen and flammable vapors are susceptible to catastrophic explosions. If the oxygen and vapor mixture is ignited by sparks, arcs, friction, compression or other heat sources, the expanding flame front may cause significant injuries and damage. One method of lessening the likelihood of a flash fire is by the installation of a flame arrestor in the equipment or on the end of a vent or process line. Flame arrestors are used in many industries, including refining, oil exploration and production, pharmaceutical, chemical, petrochemical, pulp and paper, sewage treatment, landfills, mining, power generation, and bulk liquids transportation.
Yes, OSHA has rules for the use of flammable liquids in areas that are not designed as a Hazardous Location. OSHA covers Hazardous Locations in 1910.307, but those areas that do not rise to the level of being a Hazardous Location fall under 1910.334(d) which states: