49 CFR § 393.95 - Emergency equipment on all power units.
(a) Fire extinguishers -
(1) Minimum ratings.
(i) A power unit that is used to transport hazardous materials in a quantity that requires placarding (See § 177.823 of this title) must be equipped with a fire extinguisher having an Underwriters' Laboratories rating of 10 B:C or more.
(ii) A power unit that is not used to transport hazardous materials must be equipped with either:
(A) A fire extinguisher having an Underwriters' Laboratories rating of 5 B:C or more; or
(B) Two fire extinguishers, each of which has an Underwriters' Laboratories rating of 4 B:C or more.
(2) Labeling and marking. Each fire extinguisher required by this section must be labeled or marked by the manufacturer with its Underwriters' Laboratories rating.
(3) Visual Indicators. The fire extinguisher must be designed, constructed, and maintained to permit visual determination of whether it is fully charged.
(4) Condition, location, and mounting. The fire extinguisher(s) must be filled and located so that it is readily accessible for use. The extinguisher(s) must be securely mounted to prevent sliding, rolling, or vertical movement relative to the motor vehicle.
(5) Extinguishing agents. The fire extinguisher must use an extinguishing agent that does not need protection from freezing. Extinguishing agents must comply with the toxicity provisions of the Environmental Protection Agency's Significant New Alternatives Policy (SNAP) regulations under 40 CFR Part 82, Subpart G.
(6) Exception. This paragraph (a) does not apply to the driven unit in a driveaway-towaway operation.
(b) Spare fuses. Power units for which fuses are needed to operate any required parts and accessories must have at least one spare fuse for each type/size of fuse needed for those parts and accessories.
(f) Warning devices for stopped vehicles. Except as provided in paragraph (g) of this section, one of the following options must be used:
(3) Other warning devices may be used in addition to, but not in lieu of, the required warning devices, provided those warning devices do not decrease the effectiveness of the required warning devices.
(g) Restrictions on the use of flame-producing devices. Liquid-burning flares, fusees, oil lanterns, or any signal produced by a flame shall not be carried on any commercial motor vehicle transporting Division 1.1, 1.2, 1.3 (explosives) hazardous materials; any cargo tank motor vehicle used for the transportation of Division 2.1 (flammable gas) or Class 3 (flammable liquid) hazardous materials whether loaded or empty; or any commercial motor vehicle using compressed gas as a motor fuel.
(j) Requirements for fusees and liquid-burning flares. Each fusee shall be capable of burning for 30 minutes, and each liquid-burning flare shall contain enough fuel to burn continuously for at least 60 minutes. Fusees and liquid-burning flares shall conform to the requirements of Underwriters Laboratories, Inc., UL No. 912, Highway Emergency Signals, Fourth Edition, July 30, 1979, (with an amendment dated November 9, 1981). (See § 393.7 for information on the incorporation by reference and availability of this document.) Each fusee and liquid-burning flare shall be marked with the UL symbol in accordance with the requirements of UL 912.
(k) Requirements for red flags. Red flags shall be not less than 12 inches square, with standards adequate to maintain the flags in an upright position.