49 CFR § 172.521
DANGEROUS placard
November 18, 2020
(a) Except for size and color, the DANGEROUS placard must be as follows:
(b) In addition to meeting the requirements of §172.519, and appendix B to this part, the DANGEROUS placard must have a red upper and lower triangle. The placard center area and 1⁄2 -inch (12.7 mm.) border must be white. The inscription must be black with the 1⁄8 -inch (3.2 mm.) border marker in the white area at each end of the inscription red.
[Amdt. 172-29, 41 FR 15996, Apr. 15, 1976, as amended by Amdt. 172-29A, 41 FR 40680, Sept. 20, 1976]