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Applicability determination for one chemical in different physical states

A facility is required to keep two MSDSs on file for the same hazardous chemical (oxygen); one for the gas phase and one for liquid phase because they present different risks.  Would the same chemical present at a facility in different physical states be aggregated for threshold determinations?

The applicability of EPCRA Sections 311 and 312 is based on an owner or operator having a threshold quantity of a hazardous chemical present at the facility.  Thresholds are based on the amount of hazardous chemical on site, rather than the type of hazard presented by the chemical in various phases.  The fact that a facility has two or more MSDSs for different phases of a hazardous chemical does not mean that these phases are considered different hazardous chemicals.  In this case, oxygen is a single hazardous chemical.  Even if a facility receives multiple MSDSs for oxygen because it is provided by different suppliers, or is received in different phases presenting different risks, the facility must aggregate all quantities of the oxygen present at the facility for threshold determinations.