No matter what industry your business is involved in, if you ever ship, package, or handle hazardous materials, it’s important to understand the labeling requirements associated with potentially dangerous substances. 

In the United States, the Environmental Protection Agency (EPA), Department of Transportation (DOT), and Occupational Safety and Health Administration (OSHA) maintain strict standards regarding how hazardous materials should be packaged, labeled, and handled. These rules are extensively detailed and are broken into numerous categories, covering everything from explosives (e.g. fireworks, ammunition, etc.) to radioactive waste.

Compiled in the Code of Federal Regulations, the labeling requirements for hazardous materials rules slightly vary on a substance-by-substance basis. Accordingly, it’s important to know what requirements specifically apply to the substances that your organization handles. 

Below, we detail the basics of U.S. hazmat labeling legislation if you’re unsure of how to deal with the hazardous materials used in your operation.

Agencies That Maintain Hazardous Material Labeling Requirements in the U.S.

In the United States, all hazardous materials are required to be labeled with specific information laid out in the Code of Federal Regulations. OSHA is the agency in charge of writing these labeling standards and enforcing them via the Hazard Communication Standard (HCS). The basic mission of the HCS is to ensure that workers are well aware of what chemicals they are using and what hazards they may pose. 

To accomplish this, the HCS maintains that:

1. “Chemical manufacturers and importers are required to evaluate the hazards of the chemicals they produce or import, and prepare labels and safety data sheets to convey the hazard information to their downstream customers.”
   
2. “All employers with hazardous chemicals in their workplaces must have labels and safety data sheets for their exposed workers, and train them to handle the chemicals appropriately.”

While OSHA is the agency that compels companies to label their hazardous materials, the EPA also plays a significant role in dictating what information must be included on the labels and what their physical properties must be. These label requirements are recorded in the Code of Federal Regulations. Additionally, the DOT requires those transporting hazardous materials to inspect packages to ensure that they are properly labeled in accordance with federal regulations. 

Below, we take a closer look at what’s included in these label requirements.

A Look Inside the Code of Federal Regulations 

As mentioned above, the Code of Federal Regulations lays out labeling requirements for all hazardous materials and specifies what physical properties these labels must have. Given how many hazardous materials there are and how different they are from one another, federal regulations separate these materials into nine classes, each accompanied by a specific set of unique rules. 

Here is a brief breakdown of each class:

• Class 1 - Explosives: This class includes materials that are designed to explode when exposed to certain conditions. Common examples include ammunition and fireworks. Explosive labeling requirements are covered in 49 CFR § 172.411.1-6.
  
• Class 2 - Gases: This class includes all packages that are filled with any form of compressed gas. Common examples include natural gas containers, fire extinguishers, and methane. Gas labeling requirements are covered in 49 CFR § 172.415-172.417, where they are subdivided into three smaller categories:
  • Non-flammable gases (covered in 49 CFR § 172.415)
  • Poison gases (covered in 49 CFR § 172.416)
  • Flammable gases (covered in 49 CFR § 172.417)
    
• Class 3 - Flammable Liquids: This class includes liquid materials that will ignite in general ignition conditions. Common examples include gasoline, kerosene, and paint. Flammable liquid labeling requirements are covered in 49 CFR § 172.419.
  
• Class 4 - Flammable Solids: This class includes solid materials that are likely to ignite when exposed to certain conditions or inadvertently placed near a flame. Common examples include matches, oily fabrics, and metal powders. Flammable solid labeling requirements are covered in 49 CFR § 172.420-172.423, where they are subdivided into three smaller categories:
  • General flammable solids (covered in 49 CFR § 172.420)
  • Spontaneously combustible solids (covered in 49 CFR § 172.422)
  • Solids that are dangerous when wet (covered in 49 CFR § 172.423)
    
• Class 5 – Oxidizers and Organic Peroxides: This class includes liquid materials that become unstable when exposed to certain environments or other materials. Common examples include nitrate and hydrogen peroxide. Oxidizer labeling requirements are covered in 49 CFR § 172.426, while organic labeling requirements are covered in 49 CFR § 172.427.
  
• Class 6 – Toxic Substances: This class includes materials that can be toxic to human beings when ingested or handled improperly. Common examples include acid and dye. Poisonous substance labeling requirements are covered in 49 CFR § 172.429 -  172.432 where they are subdivided into three smaller categories:
  • Poison inhalations (covered in 49 CFR § 172.429)
  • General poisons (covered in 49 CFR § 172.430)
  • Infectious substances (covered in 49 CFR § 172.432)
    
• Class 7 – Radioactive Substances: This class includes materials that contain radioactive matter. Common examples include nuclear waste and medical isotopes. Radioactive substance labeling requirements are covered in non-consecutive regulation segments where they are subdivided into four smaller categories:
  • Radioactive category I (covered in 49 CFR § § 172.436)
  • Radioactive category II (covered in 49 CFR § 172.438)
  • Radioactive category III (covered in 49 CFR § 172.440)
  • Fissile materials (covered in 49 CFR § 172.441)
    
• Class 8 – Corrosives: This class includes materials that can destroy body tissue with direct exposure. Common examples include hydrochloric acid and ammonium hydroxide. Corrosive labeling requirements are covered in 49 CFR § 172.442.

• Class 9 – Miscellaneous Hazards: This class includes materials that don’t quite fit with the other classes but are nonetheless hazardous. Common examples include dry ice and lithium-ion batteries. Miscellaneous hazard labeling requirements are covered in 49 CFR § 172.446 and lithium-ion battery labeling requirements are covered in 49 CFR § 172.447.

For the most part, these different requirements relate to what label must be placed on the product packaging, where the label must go, and what colors must be used. Regardless of the specific material these labels are placed on, each label must meet these standards established in 49 CFR § 172.407:

1. Durability: Each label must be durable, weather-resistant, and able to withstand a 30-day exposure to transportation conditions without deterioration or changing color.
2. Design: Each label must follow the design instructions established in its responding class.
3. Size: Each label must be diamond-shaped with sides no less than 100 mm long unless the package’s dimensions make this impossible.
4. Color: Each label must follow the coloring instructions established in its responding class. All symbols, text, numbers, and borders must be black unless otherwise specified in the class instructions. The colors must be able to withstand a 72-hour fadeometer test as well.

In addition to these rules, chemical handlers must also follow the placement instructions laid out in 49 CFR § 172.406. These instructions state that all labels must:

1. “Be printed on or affixed to a surface (other than the bottom) of the package or containment device containing the hazardous material; and
2. Be located on the same surface of the package and near the proper shipping name marking, if the package dimensions are adequate.”

Along with these instructions, this regulation section also specifies that:

• If multiple labels are required for a single package, they should be displayed right beside one another.
• Each label must be printed on or affixed to a background color contrasting to the color specification.
• The label must always be visible.

Subscribe for More on Labeling Requirements for Hazardous Materials

In this article, we have examined the different forms of U.S. legislation that dictate how hazardous materials need to be labeled. However, there’s much more to hazardous material packaging than just applying hazard class labels. For example, chemical packaging groups also need to include harmonized signal words, pictograms, and hazard statements on every product. 

To learn about these elements, stay tuned to Coding and Marking Digest for future articles on hazardous materials labeling.

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