Marking Requirements
Pipeline and Hazardous Materials Safety Administration · Apr 9, 1996 · Reference No. 96-0201
Interprets: 49 CFR § 172.304
Reggie’s quick take
Someone asked whether a pouch can carry the markings required by § 172.304. PHMSA said yes, if the required marking is clearly visible through a translucent pouch. Shading that limits visibility is not allowed. Printed words like "Packing List" are fine if the required marking is still clearly identifiable and visible. Any method that attaches the marking durably is acceptable, including adhesive. A perforated opening is also fine, as long as the marks stay on the package during transport.
Written by AI (Claude) on Oct 22, 2026. Robots make mistakes and leave things out, so the letter below is what counts. Not legal advice.
This is in response to your letter requesting clarification of the marking requirements in § 172.304 as they apply to several questions you presented.
Would a clear translucent pouch be acceptable for marking, if the words showing through the outer layer were clearly visible? If so, at what point would a somewhat shaded pouch be considered not acceptable? What about a pouch with "packing list" or other verbiage printed on the outside of the pouch? At what point would this be "obscured"?
As specified in § 172.304 marking must be durable, in English, printed on or affixed to the surface of a package, on a label, tag, or sign. The marking must be displayed on a sharply contrasting background and must be unobscured by labels or attachments and must be located away from any other marking that could substantially reduce its effectiveness. These requirements are basically performance standards. Use of a translucent pouch is acceptable provided the required marking is clearly visible. Shading that restricts visibility is not acceptable. Similarly, if the pouch indicated "Packing List" and the required marking was otherwise clearly identifiable and visible, it would be acceptable.
Is there a concern over the fact that the pouch itself used adhesive in order to remain "durable" on the package? Or do you agree that this is similar to someone using an adhesive label with the markings imprinted on the label and therefore acceptable?
Any method that affixes the required markings to the package in a durable manner is acceptable.
In the event that the pouch has a perforated closure that has been provided for the recipient to easily open the pouch, does this make the pouch marking system not acceptable due to durability?
Provided the required marks remain on the package during transportation, the use of perforations is not prohibited.
A letter of interpretation applies the regulations to the facts the requester described. It isn’t a regulation and isn’t legal advice. The agency’s copy.