This week we saw OSHA issue a $1.5M citation after an explosion killed four workers at a silicon chemical products manufacturer. All of the citations were classified as Willful and all were related to using equipment that was not approved for a hazardous location (HAZLOC). This week I was working with a client doing a PHA that involved heating the batch(s), which contained Class IIIB combustibles, to temperatures well above their flashpoints and we were had to do a HAZLOC assessment for the process building. The first thing we have to recognize is that NFPA 497 still uses “Flammable Classes” and OSHA now uses Flammable Categories.
So let’s first look at the definitions: