49 CFR § 172.304
Marking requirements
November 18, 2020
(a) The marking required in this subpart—
(1) Must be durable, in English and printed on or affixed to the surface of a package or on a label, tag, or sign.
(2) Must be displayed on a background of sharply contrasting color;
(3) Must be unobscured by labels or attachments; and
(4) Must be located away from any other marking (such as advertising) that could substantially reduce its effectiveness.
(b) [Reserved]
[Amdt. 172-29, 41 FR 15996, Apr. 15, 1976, as amended by Amdt. 172-29B, 41 FR 57067, Dec. 30, 1976]