Once again I go to the well that just keeps on giving guidance… the International Fire Code (IFC). And again I do this as OSHA nor EPA have any standards for Chlorine when the amount is below the 1,500 pounds for OSHA’s PSM standard to apply. Of course, there is EPA’s RMP General Duty Clause, but this provides us with zero help in establishing the minimum design and operational standards. The IFC establishes a nice set of minimum requirements we can apply to our chlorine storage/handling/processing. But to be fair, we must first establish Chlorine as either a “Highly Toxic” or a “Toxic” hazardous material. This is needed because the IFC has different requirements based on the level of toxicity a HAZMAT may present. Very early in my career, I was introduced to Chlorine and Bromine and both organizations managed these materials as “Highly Toxic”; however, both of the organizations were world-class in the engineering of their chemical processes (PSM or not!). So the question is… where does Chlorine fall on the scale of toxicity?
Let’s first look at the IFC’s definitions of Highly Toxic and Toxic, which are simply based on the HAZMAT’s LD50 or LC50 levels: