How is the STQ for theft/diversion-WME chemicals of interest (COI) calculated in a mixture?
If a theft/diversion-WME COI present in a mixture in an amount at or above the applicable minimum concentration amount listed in the Minimum Concentration column of Appendix A, the facility shall count the entire amount of the mixture toward the STQ unless a specific minimum concentration is assigned in the Minimum Concentration column of appendix A to part 27, in which case the facility should count the total quantity of all commercial grades of the chemicals at or above the specified minimum concentration. See ยง27.203(b)(2). Additional guidance on how theft/diversion-WME COI are treated under CFATS can be found in the preamble to appendix A to CFATS at 72 FR 65405.
