Classification of a Material Having More Than one Hazard – 49 CFR 173.2a

Classification of a Material Having More Than one Hazard – 49 CFR 173.2a

As a Shipper you are required to classify a hazardous material prior to offering it for transportation; to do this you must be familiar with the definition of a hazardous material at 49 CFR 171.8.

Hazardous material means a substance or material that the Secretary of Transportation has determined is capable of posing an unreasonable risk to health, safety, and property when transported in commerce, and has designated as hazardous under section 5103 of Federal hazardous materials transportation law (49 U.S.C. 5103). The term includes hazardous substances, hazardous wastes, marine pollutants, elevated temperature materials, materials designated as hazardous in the Hazardous Materials Table (see 49 CFR 172.101), and materials that meet the defining criteria for hazard classes and divisions in part 173 of this subchapter.

Since the definition of a hazardous material includes “…materials that meet the defining criteria for hazard classes and divisions…” it is critical that you know what those hazard classes and divisions are.  49 CFR 173.2 indicates the hazardous material classes and divisions determined by PHMSA for the classification of a hazardous material; they are:

  • Class 1 Explosives
    • Division 1.1 Explosives with a mass explosion hazard
    • Division 1.2 Explosives with a projection hazard
    • Division 1.3 Explosives with predominately a fire hazard
    • Division 1.4 Explosives with no significant blast hazard
    • Division 1.5 Very insensitive explosives; blasting agents
    • Division 1.6 Extremely insensitive detonating substances
  • Class 2 Compresses gases
    • Division 2.1 Flammable gas
    • Division 2.2 Non-flammable compressed gas
    • Division 2.3 Poisonous gas
  • Class 3 Flammable and combustible liquid
  • Class 4 Flammable and reactive solids
    • Division 4.1 Flammable solid
    • Division 4.2 Spontaneously combustible material
    • Division 4.3 Dangerous when wet material
  • Class 5 Oxidizers and organic peroxides
  • Division 5.1 Oxidizer
  • Division 5.2 Organic peroxide
  • Class 6 Poisonous/Toxic materials
    • Division 6.1 Poisonous materials
    • Division 6.2 Infectious substances (Etiologic agent)
  • Class 7 Radioactive material
  • Class 8 Corrosive material
  • Class 9 Miscellaneous hazardous material
  • Other Regulated Material: ORM-D

But what if your hazardous material is not listed by its technical name in the Hazardous Materials Table of 49 CFR 172.101 and it meets the defining criteria of more than one hazard class or division?  What then?  In that case, the Shipper must determine which of the hazards is the primary and which is the subsidiary – or subsidiaries if there is more than one.  The purpose of this article is to explain the procedure at 49 CFR 173.2a for classifying a hazardous material that has more than one hazard.

Some HazMat with more than one hazard class or division are not required to be classified according to the directives of 49 CFR 173.2a, they include:

  • Those with their technical names or are otherwise specifically listed in the Hazardous Materials Table of 49 CFR 172.101.  If so, the primary and subsidiary hazard classes or divisions will be determined by their sequence in column 6 Label Codes of the Table.
  • 49 CFR 173.2a(c) identifies 5 HazMat with unique properties that preclude classification according to the procedures of 49 CFR 173.2a and must be classified according to other specific regulations; they include:
    • Class 1 explosive materials.
    • Division 5.2 Organic peroxide.
    • Division 6.2 Infectious substance.
    • Division 4.1 Flammable solid that meets the definition of a wetted explosive in 49 CFR 172.124(a)(1).
    • A limited quantity of a Class 7 Radioactive.

So, if your HazMat meets the defining criteria of more than one hazard class or division, and it is not one of those identified above, then its primary hazard class must be determined from the following in descending order of hazard:

(1) Class 7 Radioactive materials (other than Limited Quantities).
(2) Division 2.3 Poisonous gases.
(3) Division 2.1 Flammable gases.
(4) Division 2.2 Nonflammable gases
(5) Division 6.1 Poisonous liquids (Packing Group I, Poisonous-by-inhalation only).
(6) Division 4.2 Spontaneously combustible that meets the definition of a Pyrophoric material.
(7) Division 4.1 Flammable solid that meets the definition of a self-reactive material.
(8) The following must be classified according to the Precedence of Hazard Table at 49 CFR 173.2a(b):

  • Class 3 Flammable liquids.
  • Class 8 Corrosive materials.
  • Division 4.1 Flammable solids.
  • Division 4.2 Spontaneously combustible materials.
  • Division 4.3 Dangerous when wet materials.
  • Division 5.1 Oxidizers.
  • Division 6.1 Poisonous liquids or solids other than Packing Group I poisonous-by-inhalation.

If you must utilize the Precedence of Hazard Table, you will need to know the Packing Group of the HazMat.  Also, be sure to read and consider the Notes that follow it.

And then, back to our precedence of hazards in descending order…

(9) Combustible liquids.

(10) Class 9 Miscellaneous hazardous materials.

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Determine the primary and subsidiary hazard classes from the following examples:

Example 1:  A hazardous material meets the defining criteria of Division 2.1 Flammable gas and Class 8 Corrosive material.

Answer 1:  Division 2.1 Flammable Gas is higher on the list (3) than Class 8 Corrosive material (8).  Therefore Division 2.1 Flammable gas is the primary hazard class and Class 8 Corrosive material is the subsidiary hazard class.

Example 2:  The classification of a hazardous material resulted in the selection of Butyronitrile as a proper shipping name in column 2 of the Hazardous Materials Table.  It also meets the defining criteria of a Class 3 Flammable liquid and a 6.1 Poisonous material.

Answer 2:  Since Butyronitrile is specifically identified in the Hazardous Materials Table, it must be classified according to the precedence of hazards listed in column 6 of the Table.  Therefore, Class 3 Flammable liquid is the primary hazard and Class 6.1 Poisonous material is the subsidiary hazard.

Example 3:  A hazardous material meets the defining criteria of a Class 3 Flammable liquid (Packing Group I) and a Class 8 Corrosive material (liquid, Packing Group I).

Answer 3:  Both Class 3 Flammable liquid and Class 8 Corrosive material must be classified according to the Precedence of Hazard Table:  A Class 3 Flammable liquid (Packing Group I) is the primary hazard and the Class 8 Corrosive material (liquid, Packing Group I) is the subsidiary hazard.

P of H Table

 

Example 4:  A hazardous material meets the defining criteria of a Class 3 Flammable liquid (Packing Group II) and a Class 8 Corrosive material (liquid, Packing Group I).

Answer 4:  Both Class 3 Flammable liquid and Class 8 Corrosive material must be classified according to the Precedence of Hazard Table:  The Class 8 Corrosive material (liquid, Packing Group I) is the primary hazard and the Class 3 Flammable liquid (Packing Group II) is the subsidiary hazard.

P of H Table 2

 

Example 5:  A hazardous material meets the defining criteria of a Division 6.1 (liquid, Packing Group I, poisonous-by-inhalation only), Class 8 Corrosive (liquid, Packing Group I), and a Class 3 Flammable liquid (Packing Group III).

Answer 5:  The Division 6.1 Poisonous liquid, Packing Group I, poisonous-by-inhalation only is higher on the list than are either Class 3 Flammable liquid or Class 8 Corrosive material, therefore it will be the primary hazard class.  Class 3 Flammable liquid and Class 8 Corrosive material must be classified according to the Precedence of Hazard Table.  There we see that a Class 8 Corrosive liquid of Packing Group I is primary over a Class 3 Flammable liquid of Packing Group III.  Therefore the primary hazard class/division is 6.1 Poisonous material, the first subsidiary hazard is Class 8 Corrosive material and the second subsidiary hazard is Class 3 Flammable liquid.

P of H Table 3

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Determining the hazard class or division for your HazMat and then determining the correct precedence of hazards is not easy, but it can be done with the proper information, access to the regulations, and time.  If your time is in short supply, contact me to provide the training you need to address challenges like these and many other found in the Hazardous Materials Regulations.