(a)Appeal. This part applies to applicants who are appealing an Initial Determination of Threat Assessment or an Initial Determination of Threat Assessment and Immediate Revocation in a security threat assessment (STA) as described in each of the following:(1) 49 CFR part 1572 for a hazardous materials endorsement (HME) or a Transportation Worker Identification Credential (TWIC).(2) 49 CFR part 1540, subpart C, which includes individuals engaged in air cargo operations who work for certain aircraft operators, foreign air carriers, indirect air carriers (IACs), or certified cargo screening facilities.(b)Waivers. This part applies to applicants for an HME or TWIC who undergo a security threat assessment described in 49 CFR part 1572 and are eligible to request a waiver of certain standards. 72 FR 3588 , Jan. 25, 2007, as amended at 74 FR 47695 , Sept. 16, 2009; 76 FR 51867 , Aug. 18, 2011