Hazmat Label Basics: Part II

Posted on 1/2/2020 by Roger Marks

In Part 1 of our Hazmat Label Basics series, we discussed two major rules that everyone who labels hazmat packages must know.

To recap, all hazmat labels must:
  • Be printed on or affixed to a surface OTHER THAN THE BOTTOM of the package or containment devices containing the hazardous material (49 CFR 172.406(a)(1)(i)).
  • Be located on the same surface of the package and near the proper shipping name marking, if the package dimensions are adequate (49 CFR 172.406(a)(1)(ii)).

Now, let’s go a bit deeper and review some other general requirements for hazmat labels found in the 49 CFR Hazardous Materials Regulations (HMR). We’re covering the basics here. For full specifications and requirements for hazmat label size, color, and wording, see 49 CFR Part 172, Subpart E. Regulatory reference are provided below to point you in the right direction.  

Hazmat Label Size Specifications

Hazmat labels are designed to be affixed square-on-point, in a diamond orientation. Each side of the diamond must measure at least 100 mm. (i.e., 3.9 inches). Labels must fit on one side of your package.

DOT also specifies a size requirement for label borders. Each label must have an inner border that is at least 2 mm. wide and appears 5 mm. from the label’s edge.

Individual elements found on hazmat labels must meet strict size specifications as well: The hazard class/division shown on the label must be at least 6.3 mm (0.25 inches) tall. When the label features lettering that describes the hazard, i.e. “FLAMMABLE,” those letters must be at least 7.6 mm (0.3 inches) tall.  

Hazmat Label Color Specifications

You may have noticed that every flammable liquid (Class 3) label is red. In fact, they are all the same specific “shade” of red. That’s because the 49 CFR hazmat regulations use the Pantone numbering system to specify the required color of hazmat labels.


More Hazmat Label Color Specs

To make sure everyone can see the information on your hazmat label, the text, hazard class/division number, and borders on a hazmat label must be printed in black.

There are a few exceptions to this rule:

  • On the corrosive label (Class 8), text and the hazard class number must appear in white.
  • Text and symbols may be white on labels with red, blue, or green backgrounds.
  • On the organic peroxide hazmat label (Division 5.2), the hazard symbol may be white.
(see 49 CFR 172.407(d))

Contrast with Background Color

A hazmat label must contrast with the “background color,” meaning the color your package or container.

When the label does not contrast with the background color – for example, if you’re shipping flammable liquids (Class 3) in a red box or corrosives (Class 8) in a white bulk tank—the label must have a dotted or solid line outer border to make sure it is clearly visible to supply chain personnel and emergency responders. 

Durability and Weather Resistance

US DOT requires that all hazmat labels be “durable and weather resistant”. Specifically, 49 CFR 172.407(a) states that labels on a package must be able to withstand, without deterioration or a substantial change in color a 30-day exposure to normal transportation conditions.

Labeling Materials with More Than One Hazard

Some hazardous materials are regulated for more than one reason. A flammable liquid may also be corrosive, like formaldehyde solutions.

When your material has both a primary and a subsidiary hazard, in most cases it will require a hazmat label for each. When placing multiple hazmat labels on a single package, the labels must be placed within six inches of each other (150 mm.). 

Use of Tags Instead of Labels

Some packages or containers are not label-ready –either because they are too small, awkwardly shaped, or otherwise not label-able.  

For domestic transportation only, the hazmat label may be printed on or placed on a tag securely fixed to the following packages/containers:
  • A package that contains no radioactive material and is too small for a required label
  • Cylinder; and
  • A package with such an irregular surface that a label cannot be satisfactorily affixed. 
(see 49 CFR 172.406(b))

Don’t Hide Your Hazmat Labels!

Lastly, hazmat labels are only useful when they can be seen clearly. For this reason, hazmat labels must always be placed so that they are not obscured by other markings, attachments, package branding, etc.

Hazmat Label Basics: Part II

Tags: dangerous goods, hazardous materials, hazmat labels, hazmat shipping, labels

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