49 CFR 172.540 - POISON GAS placard.
(a) Except for size and color, the POISON GAS placard must be as follows:
(b) In addition to complying with § 172.519, the background on the POISON GAS placard and the symbol must be white. The background of the upper diamond must be black and the lower point of the upper diamond must be 65 mm (2 5/8 inches) above the horizontal center line. The text, class number, and inner border must be black.