49 CFR § 172.336 - Identification numbers; special provisions.
(b) Identification numbers, when required, must be displayed on either orange panels (see § 172.332(b)) or on a plain white square-on-point display configuration having the same outside dimensions as a placard. In addition, for materials in hazard classes for which placards are specified and identification number displays are required, but for which identification numbers may not be displayed on the placards authorized for the material (see § 172.334(a)), identification numbers must be displayed on orange panels or on the plain white square-on-point display configuration in association with the required placards. An identification number displayed on a white square-on-point display configuration is not considered to be a placard.
(1) The 100 mm (3.9 inch) by 215 mm (8.5 inches) area containing the identification number shall be located as prescribed by § 172.332 (c)(1) and (c)(2) and may be outlined with a solid or dotted line border.
(c) Identification Numbers are not required:
|On the ends of portable tanks, cargo tanks, or tank cars||They have more than one compartment and hazardous materials with different identification numbers are being transported therein||The identification numbers on the sides of the tank are displayed in the same sequence as the compartments containing the materials they identify.|
|On cargo tanks||They contain only gasoline||The tank is marked “Gasoline” on each side and rear in letters no less than 50 mm (2 inches) high, or is placarded in accordance with § 172.542(c).|
|On cargo tanks||They contain only fuel oil||The cargo tank is marked “Fuel Oil” on each side and rear in letters no less than 50 mm (2 inches) high, or is placarded in accordance with § 172.544(c).|
|On one end of nurse tanks if that end contains valves, fittings, regulators or gauges when those appurtenances prevent the markings and placard from being properly placed and visible||They meet the provisions of § 173.315(m) of this subchapter||N/A.|
|On cargo tanks, including compartmented cargo tanks, or tank cars||They contain more than one petroleum distillate fuel||The identification number for the liquid petroleum distillate fuel having the lowest flash point is displayed. If the cargo tank also contains gasoline and alcohol fuel blends consisting of more than 10% ethanol the identification number “3475” or “1987,” as appropriate, must also be displayed.|
(d) When a bulk packaging is labeled instead of placarded in accordance with § 172.514(c) of this subchapter, identification number markings may be displayed on the package in accordance with the marking requirements of § 172.301(a)(1) of this subchapter.