US DOT/PHMSA Issues Interpretation Letter Regarding Class 9 Labels and Placards

In the July 20th, 2011 edition of the US Federal Register, the United States Department of Transportation’s (USDOT) Pipeline & Hazardous Materials Safety Administration (PHMSA) published a final rule under [Docket No. PHMSA–2009–0151 (HM–218F)] under which the agency, among many other things, set forth new specifications and requirements governing the appearance of the Class 9 Hazard label.

In a nutshell, PHMSA removed the horizontal line that enclosed the bottom of the vertical stripes on the label. This is what a pre-7/20/2011 label looked like (other than size):







Under the new provisions in US 49 CFR 172.446, the appearance of the label was recast, thus (other than size):

International Hazard Class 9 Placard

Note the removal of the horizontal line. This was done to conform US transport regulations in this area more closely to those of the United Nations Model Regulations (UNMR). The appearance of the “new” label matches that of the UNMR.

Need DOT Hazard Class Labels? We Have Your Solution!



Along with the mandate for the new style label came direction on how long the old style label could be used, in order to allow drawdown of existing stock. This is commonly called the transition period, and in the rule PHMSA set October 1st, 2014 as the date that the old style label would no longer be authorized for use.

A formal Letter of Interpretation was issued on September 30th of 2014 by Director of Standards and Rulemaking Charles E. Betts to the Council on Safe Transportation of Hazardous Articles (COSTHA), a Dangerous Goods Transportation Industry association. In this letter, PHMSA made a reversal, issuing an interpretation which specifically permits the continued use of the “old” Class 9 label (i.e. the type featuring the horizontal line). The same letter also included language allowing the removal of the horizontal line from domestic class 9 placards.

To view the Letter of Interpretation issued by the agency follow the link below:

Labelmaster is a full service provider of goods and services for the Hazardous Materials and Dangerous Goods professional, shippers, transport operators, and EH&S providers. See our full line of solutions at

COSTHA is the Council on Safe Transportation of Hazardous Articles, an industry group that works to assist the regulated community with many facets of Dangerous Goods Transport. You can find out more about COSTHA and what they do at

Author Comments:

There was some anecdotal evidence within the DG industry that the US Class 9 labels were running into trouble or delay in the EU, so the initial action by the agency may have been intended in part to help smooth the path for US trade in that sector. As the transition date approached, there was some interest in the DG community to have yet another extension of that deadline to allow at least temporary continued use of the “old” style label (i.e. the version with the horizontal line); however, as September passed without further action, that potential appeared to recede.

To some, the issuance of the interpretation letter may be deemed an unanticipated action by the agency. Given the difference between US and international versions of the Class 9 placard, this is certainly an action which may have confusing effects down the road—literally! Note that none of these actions are stated as mandatory—they are all “mays” rather than “musts.” It is also vital to note that today’s action has NO impact on rules for shipping via international rules under the ICAO or IMO regulations—it is “domestic only.”

Further clarification to this now somewhat ambiguous issue will appear in the Labelmaster Blog as it becomes available, so please watch this space for continued updates.


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  1. OHYA Kazumasa said:

    I was worried about “Horizontal line of class9 label” , when I first join into HAZMAT transportation job.
    But my current opinion is “Horizontal line is OPTIONAL” according to 49CFR 172.446(b). Therefore Horizontal line problems are settled for me.
    Sad to say, I couldn’t find the real viewpoint of this blog,

    Now, I beg two favor of you about label problems.
    One is international reguration about labeling.
    Only IMDG code use a horizontal line for class9 label.
    ICAO TI stop using horizontal line few years ago, but they permit labels of IMDG Code.
    Another one is a width of surrounding diamond line of hazmat label in this blog.
    I have no choice other than changing label design from 2015 or 2016. Because I use approximetaly 1mm width line now, but UN require 2mm width from 2015.