Section 397.1 - Application of the rules in this part(a) The rules in this part apply to each motor carrier engaged in the transportation of hazardous materials by a motor vehicle which must be marked or placarded in accordance with § 177.823 of this title and to- (1) Each officer or employee of the motor carrier who performs supervisory duties related to the transportation of hazardous materials; and(2) Each person who operates or who is in charge of a motor vehicle containing hazardous materials.(b) Each person designated in paragraph (a) of this section must know and obey the rules in this part.36 FR 4876, Mar. 13, 1971, as amended at 36 FR 16067, Aug. 19, 1971; 53 FR 18058, May 19, 1988; 60 FR 38749, July 28, 1995