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The Four Hazard Communication Methods of the Hazardous Material Regulations

The Four Hazard Communication Methods of the Hazardous Material Regulations

The Hazardous Material Regulations (HMR) of the PHMSA/USDOT require the use of the four (4) hazard communication methods whenever a hazardous material is transported in commerce.   Its purpose:  to communicate the potential hazards of a material to anyone who may come into contact with it while it’s in transportation.  It does this by utilizing a variety of symbols, numbers, colors, and text.  This article will take a closer look at each of the Four Hazard Communication Methods:

  • Shipping papers
  • Placards
  • HazMat labels
  • Markings

One common mistake is to confuse the hazard communication methods as required by the PHMSA/USDOT with Hazard Communication or HazCom which is required by the regulations of OSHA at 29 CFR 1910.1200.  Though they share a similar purpose in that they are meant to communicate the hazards of a material, the regulations of OSHA apply to the worker in the workplace whereas those of the PHMSA/USDOT take precedence when a hazardous material is in transportation or offered for transportation.

Though in general the four hazard communication methods are to be used whenever a HazMat is transported, there are exceptions to the HMR that allow for transportation without the use of some or even all four of the hazard communication methods.  It is the responsibility of the shipper to determine the applicability of any exceptions to their shipment and to apply each of the hazard communication methods accordingly.

A helpful way to remember each of the four hazard communication methods is to understand their purpose, which is to communicate the potential hazards of the material to anyone (other HazMat Employees; police, fire, emergency response; and the general public) who may come in contact with it while in transportation.  Each of the four hazard communication methods has a unique way to meet this purpose; the four hazard communication methods are:

Shipping Papers:

For the purpose of the HMR, a shipping paper is simply a document used to describe the hazardous material in transportation.  The shipping paper may take many forms as long as it contains a description of the HazMat as required by the PHMSA.  As a matter of fact, I was told by a PHMSA official that as far as they’re concerned the shipping paper could be hand-written on a piece of scratch paper, as long as it serves its purpose as required by regulation.  A helpful way to think about the shipping paper is that it should be the story of the HazMat shipment; everything a person needs to know about that shipment should be contained in the shipping paper.  Remember that other regulatory agencies will have additional requirements if the transportation of HazMat is under their jurisdiction as well, two examples:

  • The transportation of hazardous waste on a Uniform Hazardous Waste Manifest will be subject to the regulations of the USEPA and your state as well if it has an authorized hazardous waste program as most do.
  • Transportation involving a paid carrier where a Bill of Lading is the shipping paper.  Both the Federal Motor Carrier Safety Administration (FMCSA) and state regulations will impact the completion of the shipping paper for shipments of this type.

The shipping paper is to be completed, reviewed, and signed by a representative of the shipper, though it is not uncommon for the carrier to provide a completed HazMat shipping paper to the shipper for review and signature.  While the carrier’s signature is not required in all situations (the Uniform Hazardous Waste Manifest is an exception to this), the carrier is required to reject the load if the shipping paper contains errors or is lacking the shipper’s certification and signature, so some review of the shipping paper by the carrier prior to acceptance is necessary.  The shipping paper must remain with the hazardous material at all times while it is in transportation.  This includes time at a 10-Day Transfer Site where a hazardous material may be removed from a vehicle and stored in a warehouse for up to ten days.  Copies of the shipping paper must be kept as a record by both the shipper and the carrier, but not the receiver (again, the Uniform Hazardous Waste Manifest is an exception to this).  In the event of an emergency, the driver, if possible, is to provide the shipping papers to emergency responders.


Placards are diamond-shaped warning signs affixed to the outside of vehicles and some bulk packagings such as a portable tank.  Their primary purpose is to alert first responders (and to a lesser extent the general public) to the presence and type of hazardous materials in a vehicle or bulk packaging.  I’m sure everyone has seen the colorful placards on highway vehicles and perhaps even adjusted their driving habits accordingly.  Two limitations to relying solely on placards to communicate the potential hazards of a material is that placards are not required for all shipments of HazMat and even when present placards don’t communicate the amount of hazardous materials present.  The shipper and/or carrier must ensure that placards are displayed in such a manner that they are visible while in transportation; generally this means on all four sides of a vehicle, and on at least two sides of a bulk packaging (with exceptions).

HazMat Labels:

HazMat labels are similar to placards in appearance, though much smaller (labels are ~4″ per side while placards are ~10″ per side), and with two key differences:

  1. HazMat labels are applied solely to packagings (both bulk and non-bulk), never to a vehicle, and;
  2. There is no threshold determination or criteria for use of a HazMat label.  The hazard class of a material must be communicated by a HazMat label on the packaging, unless excepted.

The size and location of HazMat labels on the packaging precludes their view and use during normal transportation by anyone other than the HazMat Employees responsible for handling the packaging.


Markings are additional information applied to the outside of a hazardous material packaging.  This additional information will vary depending on the HazMat being shipped and on the type of packaging (bulk and non-bulk); with non-bulk packagings requiring more information while bulk packagings rely on the placards to communicate the potential hazards of the material.  Like HazMat labels, due to their size and placement on the package, it will be the HazMat Employees who physically handle the packagings that get the most use from Markings.

Look for the four hazard communication methods during the next shipment of hazardous material you are involved with.  Ask yourself:

  1. Who prepares, reviews, and signs the shipping paper?
  2. What placards are required for the shipment, if any?
  3. What HazMat labels and markings appear on the packaging?
  4. And finally, what are the potential hazards of this material?

If you are not able to answer these questions satisfactorily, then perhaps you should consider one of my Public Training Seminars.