Section 135.501 - Applicability and definitions(a) This subpart prescribes the requirements applicable to each certificate holder for training each crewmember and person performing or directly supervising any of the following job functions involving any item for transport on board an aircraft: (4) Storage incidental to transport;(5) Packaging of company material; or(b)Definitions. For purposes of this subpart, the following definitions apply: (1)Company material (COMAT) -Material owned or used by a certificate holder.(2)Initial hazardous materials training -The basic training required for each newly hired person, or each person changing job functions, who performs or directly supervises any of the job functions specified in paragraph (a) of this section.(3)Recurrent hazardous materials training -The training required every 24 months for each person who has satisfactorily completed the certificate holder's approved initial hazardous materials training program and performs or directly supervises any of the job functions specified in paragraph (a) of this section.