49 CFR § 172.556 - Radioactive Placard.
---
identifier: "/us/cfr/t49/s172.556"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "49 CFR § 172.556 - RADIOACTIVE placard."
title_number: 49
title_name: "Transportation"
section_number: "172.556"
section_name: "RADIOACTIVE placard."
chapter_name: "PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION"
subchapter_number: "C"
subchapter_name: "HAZARDOUS MATERIALS REGULATIONS"
part_number: "172"
part_name: "HAZARDOUS MATERIALS TABLE, SPECIAL PROVISIONS, HAZARDOUS MATERIALS COMMUNICATIONS, EMERGENCY RESPONSE INFORMATION, TRAINING REQUIREMENTS, AND SECURITY PLANS"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
authority: "49 U.S.C. 5101-5128, 44701; 49 CFR 1.81, 1.96 and 1.97."
regulatory_source: "Amdt. 172-29, 41 FR 15996, Apr. 15, 1976, unless otherwise noted."
cfr_part: "172"
---
# 172.556 RADIOACTIVE placard.
(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]