What Do the Numbered Placards on Trucks Mean?

Save

International and federal regulations require that trucks and rail cars carrying hazardous materials bear placards indicating hazmat transport and specifying the particular materials on board. When a transportation accident takes place involving any hazardous substance, emergency responders need to know what material is being transported so they can take appropriate steps to handle the accident, protect themselves and the public. Placard numbers denote the type of material aboard the truck or rail carrier.

Meaning of UN/NA Numbers

  • Rail cars and transportation trucks are required to carry numbered placards that warn of hazardous materials on board. These four-digit numbers, called the UN/NA numbers refer to specific chemicals, or groups of chemicals. These numbers are assigned by the United Nations (U.N.) or the United States Department of Transportation (US DOT).

Explosives and Compressed Gases

  • As you drive through your community or on the interstate, large trucks share the roads with you. Because of this, government agencies require the trucking companies to affix large placards that designate what chemicals their trucks are transporting. These chemicals include explosives or any device (detonators, primers, fuzes, powder cake or propelling charges) that is designed to function by exploding. If the device is not designed to explode, but instead functions through a chemical reaction such as an explosive chemical, the truck is required to carry this placard.

    Compressed gases fall under the Class 2 hazardous materials US DOT law. They include flammable gases, non-flammable, non-poisonous gases, oxygen and any gas so toxic to humans it is regarded as a hazard to health during transportation, states 247Ritgs.com.

Flammables

  • Flammables fall into the Class 3 category of hazardous materials and include flammable liquids, combustibles, gasoline and fuel oil.

    A liquid that has a flash point of at least 35 F is required to be denoted by a hazardous materials placard. A combustible liquid with a flash point of at least 38 F is also required to be indicated with a placard.

    Dry explosives, when wet with plasticizer, water or alcohol to suppress the explosive tendency, are required to be denoted by a Class 4 placard, says the Environmental Chemistry website.

Corrosives and Oxidizers

  • The Class 8 listing covers corrosive materials such as solids or liquids that produce full thickness skin destruction on contact. In addition, when transporting corrosives, the carrier must take every precaution to segregate incompatible corrosives from each other; many react violently when they come into contact with each other, states 247Rigs.com.

Radioactive and Poisons

  • Poisonous substances are Class 6 hazardous materials required to be placarded by the UN and US DOT. Any poison that does not fall under the Hazard Zone A or B is included in this category and is marked by a Class 6 "Poison" placard on a train or large truck, writes the Environmental Chemistry website.

    A "Toxic" placard may be substituted for the "Poison" placard. A "Packing Group III" placard may also replace the "Poison" placard when the carrier is transporting Poison PG III materials.

    Radioactive materials must be denoted by a bright yellow "Radioactive Class 7" placard. Some materials, in what is called "exclusive use," are not required to carry this label. The "Radioactive" placard is required, says the Environmental Chemistry website. "Exclusive use" refers to "sole use" or "full load," in which, "all initial, intermediate, and final loading and unloading are carried out in accordance with the direction of the consignor or consignee," according to the USDOT Hazardous Materials Transportation placards website.

Miscellaneous and Other Markings

  • Any material with a noxious or anesthetic property is required to be placarded with the Class 9 "Miscellaneous" designation.

    Marine pollutants fall under the "Other Related Markings" placard requirement, according to the 247Rigs website.

References

  • Photo Credit Joe Raedle/Getty Images News/Getty Images
Promoted By Zergnet

Comments

Resources

You May Also Like

  • DOT Placard Requirements

    The U.S. Department of Transportation ... allows the carrier to use the lowest Class 1 division number placard when transporting multiple divisions...

  • Placard Requirements

    Placards must be placed on the vehicle so they are visible from both sides and both ends. Many chemicals have four digit...

  • How Do I Identify Hazmat Placards?

    These color-coded, diamond-shaped hazmat placards ... panel or a white square next to the hazmat placard. This four-digit number indicates the specific...

  • What Placards Go on a Chlorine Tanker?

    The placard also contains the number 2 at the bottom, ... According to the National Model Railroad Association, these are called residue...

  • List of Army MOS Codes

    List of Army MOS Codes. ... women and officers in the Chemical Corps fall under CMF 74 and are tasked with protecting...

  • Chemical Hazard Symbols and Their Meanings

    The number 0 represents that there is no hazard other than that which ordinary ... List of Hazard Symbols. Hazard signs can...

  • How to Determine if a Handicap Placard is Fake

    If you see a fake placard, take note of all the details, ... color, shape and any numbers on it. Be sure...

  • List of Hazard Symbols

    The key to reading hazard signs is to know what the symbols mean. ... from the trailer of a semi-truck rolling down...

Related Searches

Read Article

Packing for a Trip to the Beach

M
Is DIY in your DNA? Become part of our maker community.
Submit Your Work!