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A Comprehensive Guide To Firefighter Placards

June 12, 2024

For the benefit of firefighters and other first responders, hazmat transporters are required to label and or “mark” their loads with DOT-approved placards that identify the particular type of hazardous material they’re moving. This blog entry explores the hows & whys. Q&As include:

  1. Why are hazmat placards required for hazmat loads?
  2. What are the physical requirements for a hazardous material placard?
  3. What do different colors on hazmat placards mean?
  4. What are some examples of hazmat placards?
  5. What are DOT requirements for hazmat labeling and marking?
  6. What is the difference between hazmat “labeling” vs. “marking?”
  7. How many classes of hazardous waste are there?
  8. Where can you get comprehensive guidance about hazmat labeling and marking?


Why are hazmat placards required for hazmat loads?


While the answer to this might seem obvious (i.e., this stuff is dangerous), more nuanced explanations are thus:

  • Such placards inform drivers about what precautions to take relative to the kind of hazmat they’re handling. E.g., is it explosive, corrosive, or merely flammable?
  • They prompt firefighters and other responders about what preordained actions to initiate in the event of an uncontrolled discharge. E.g., counterintuitively, some fires grow worse when water is applied, such as Class B and Class D fires (see source).


What are the physical requirements for a hazardous material placard?


You could write a master’s thesis on this question. Per Title 49, Subtitle B, Chapter 1, Subchapter C, Part 172, Subpart F, Subsection 172.519, the requirements for hazmat placards include but definitely are not limited to:

  • Strength and durability. E.g., they must be capable of withstanding a 30-day exposure to open weather conditions.
  • Design. E.g., “the printing, inner border, and symbol must be as shown in §§ 172.521 through 172.560 of this subpart, as appropriate.”
  • Size. E.g., each square-on-point placard must measure at least 250 mm on each side and must have a solid line inner border approximately 12.5 mm inside and parallel to the edge. (If you’re not into measuring metrically, that’s about 10.0 x .50 inches.)
  • Color. See Q.3 for the requisite hues, each of which must be able to endure a 72-hour test in a “fadeometer,” and because we knew you’d ask: a fadeometer is a chamber that exposes materials to a carbon arc lamp under controlled conditions to determine how well they resist fading (see source).


What do different colors on hazmat placards mean?


Table 1 presents DOT-required placard colors and what each indicates.

BlueDangerous when wet
Red and whiteSpontaneously combustible
WhiteInhalation hazard
White and yellowRadioactive
White with black stripesMiscellaneous


What are some examples of hazmat placards?


Table 2 presents some typical “square-on-point” hazmat labels.



What are DOT requirements for hazmat labeling and marking?


There are specific DOT requirements for shipping your chemical hazardous waste offsite for disposal, storage, or treatment.

Not only must the container be clearly labeled as hazmat, it must also prominently display this notice: HAZARDOUS WASTE—Federal Law Prohibits Improper Disposal. If found, contact the nearest police or public safety authority or the U.S. Environmental Protection Agency.

Additionally, the container must clearly show your company’s name, EPA identification number, and manifest tracking number; and there might be additional requirements for bulk-packaging containers.

Labeling must be durable, clearly visible, and written in English. It must be displayed on a contrasting color background and not be obscured by other labels, attachments, or advertising.

Also bear in mind that labeling requirements differ depending on the amount of chemical hazardous waste you generate. In this regard, the EPA specifies two categories: Bulk‑packaging and Non-bulk packaging.

Loosely speaking, non-bulk packaging dictates a maximum capacity of 119 gal for a liquid waste (450 L); a maximum of 882 lbs for a solid waste (400 kg); or a water capacity of 1000 lbs for a gaseous waste (454 kg). Thereby, bulk-packaging is anything that exceeds these quantities.


What is the difference between hazmat “labeling” vs. “marking?”


For DOT purposes, the word “labeling” is a very specific thing and is applicable only to bulk‑packaging (See Q.5). Everything else (applicable to non-bulk packaging) is merely “marking.” That said:

“Labels” (aka placards) are always diamond-shape; and in addition to U.S. requirements (see Q.2) their size must adhere to international standards, measuring at least 4″ x 4″ (100 mm) on each side, square-on-point.


How many classes of hazardous waste are there?


There are nine classes of hazardous waste. In nominative numeric order they are:

  1. Explosives. Any substances, articles, or devices that explode—either intentionally or by accident.
  2. Gasses. Dangerous for being flammable or poisonous. Includes nonflammables like helium and asthma inhalers.
  3. Flammable liquids. These liquids have a flashpoint of 140°F or less, which is the temperature at which a nearby ignition source can ignite its vapors.
  4. Flammable solids. E.g., flammables such as matchsticks, spontaneous combustibles such as oily rags, or substances that are dangerous when wet, like magnesium.
  5. Oxidizing substances & organic peroxides. Oxidizers add to the combustibility of other materials; peroxides are combinations of oxidizers and organic fuel that are thermally unstable and thereby prone to releasing dangerous amounts of heat and energy.
  6. Toxic or Infectious Substances. Solids or liquids toxic to humans by way of oral, dermal, and/or inhalation exposure; and infectious materials that are pathogenic.
  7. Radioactive material. E.g., uranium and plutonium. Also, e.g., materials found in exit signs, smoke detectors, and x-ray equipment.
  8. Corrosives. Liquids or solids that cause full-thickness destruction of human skin at the site of contact within a specified period of time.
  9. Miscellaneous. A hazardous waste that cannot be properly categorized in any one of Classes 1-thru-8.
  10. Where can you get comprehensive guidance about hazmat placards, labeling, and marking?


As they tend to come from both the EPA and DOT at haphazard intervals, regulations about placards, labeling, and marking are plentiful, evolving, and challenging to track. Managing their many aspects can divert your company’s human and budgetary resources from its core mission; and whether by unawareness or misunderstanding, noncompliance can subject you to pecuniary and even criminal consequences.

Don’t take chances. Get expert advice from a renowned provider of hazardous waste management services.

We’ve earned our reputation by anticipating the needs of our clients so that waste management doesn’t become a major distraction from their corporate mission.

For more information, contact us today. Or call 888-681-8923.

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