Federal and Oregon law requires facilities to report whether they possess an extremely hazardous substance (EHS) at the threshold planning quantity (TPQ). If a facility has an EHS at or above the TPQ, it is subject to the emergency planning requirements of the federal Environmental Protection and Community Right to Know Act (EPCRA) section 302.
To determine whether you have an EHS at a TPQ, refer to EPA's List of Lists.
The consolidated list presents the TPQ (in pounds) for section 302 chemicals in the column following the CAS number.
For chemicals that are solids, there are two TPQs given (e.g., 500/10,000). In these cases, the lower quantity applies for solids in powder form with particle size less than 100 microns, or if the substance is in solution or in molten form. Otherwise, the 10,000 pound TPQ applies. If a solid EHS is in molten form, the facility must multiply the amount of EHS on-site by 0.3 before comparing to the lower listed TPQ. If a solid EHS is in solution form, the facility must multiply amount EHS on-site by 0.2 before comparing to the lower listed TPQ. The reducing factors of 0.3 for molten solids and 0.2 for solids in solution are not to be used for the 12 solid reactive chemicals are noted by footnote “a” in Appendix A and B in 40 CFR part 355. These twelve chemicals are not listed with two TPQs and higher threshold quantity of 10,000 pounds; they only have one TPQ.