Hazardous Materials Written Test Requirements for Commercial Driver License Transfer or Renewal

PURPOSE: This rule establishes the conditions under which an applicant for a commercial driver license is required to complete the written knowledge test successfully for a hazardous materials endorsement. (1) Before adding or continuing a hazardous materials endorsement, any applicant for a new, new resident transfer, or renewal of a Class A, Class B, or Class C commercial driver license shall be required to successfully complete the hazardous materials written knowledge test. (2) Any applicant for a Class A, Class B, or Class C commercial driver license where a hazardous materials endorsement is being carried over on a new license application shall be required to successfully complete the hazardous materials written knowledge test if more than one (1) year has passed since the applicant completed their previous hazardous materials written knowledge test. (3) To continue a hazardous materials endorsement, any applicant for a duplicate Class A, Class B, or Class C commercial driver license shall not be required to successfully complete the hazardous materials written knowledge test. AUTHORITY: section 302.720, RSMo Supp. 2025.* Emergency rule filed April 8, 1991, effective April 18, 1991, expired Aug. 15, 1991. Original rule filed April 8, 1991, effective Aug. 30, 1991. Emergency amendment filed July 15, 1991, effective July 25, 1991, expired Nov. 21, 1991. Amended: Filed July 15, 1991, effective Oct. 31, 1991. Amended: Filed April 16, 1993, effective Oct. 10, 1993. Amended: Filed Aug. 18, 2025, effective Feb. 28, 2026. *Original authority: 302.720, RSMo 1989, amended 1995, 2002, 2004, 2006, 2007, 2008, 2013, 2019, 2020.