49 CFR § 172.556
RADIOACTIVE placard
November 18, 2020
(a) Except for size and color, the RADIOACTIVE placard must be as follows:
(b) In addition to complying with §172.519, the background color on the RADIOACTIVE placard must be white in the lower portion with a yellow triangle in the upper portion. The base of the yellow triangle must be 29 mm ±5 mm (1.1 inches ±0.2 inches) above the placard horizontal center line. The symbol, text, class number and inner border must be black.
[Amdt. 172-123, 56 FR 66264, Dec. 20, 1991; Amdt. 172-130, 58 FR 51531, Oct. 1, 1993; 65 FR 58627, Sept. 29, 2000]