US Department of Transportation (DOT) Pipeline Hazardous Materials Safety

Recall from the Hazardous Materials Table topic that the hazard class for a hazardous material is identified in Column 3 of the HMT.

The graphic shown here will act as your portal for specific information regarding each class. When you are finished reviewing each hazard class, click EXIT
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ORM-D: Other Regulated Materials are any substances presenting a limited hazard during transportation due to their form, quantity, and packaging. Consumer commodities fall within this class.

Class 9: Miscellaneous materials present a hazard during transportation but do not meet the definition of any other hazard class.

Class 8: Corrosive materials are liquids or solids that cause full thickness destruction of human skin at the site of contact within a specified period of time or liquids having a severe corrosion rate on steel and aluminum.

Class 7: Radioactive materials emit ionizing radiation that may be harmful to humans and animals. They may also affect photographic and x-ray films. This radiation cannot be detected by human senses (sight, smell, hearing, touch, or taste) but can be detected and measured with suitable instruments.

Class 6: Poisonous/Toxic Materials and Infectious Substance are defined as follows:

• Poison/Toxic Materials are materials, other than a gas, which is known to be so toxic to humans as to afford a hazard to health during transportation.
• Infectious Substance is a material known or reasonably expected to contain a pathogen.

Class 5: Oxidizer and Organic Peroxide materials are defined as follows:

• Oxidizers are types of material that may, generally by yielding oxygen, cause of enhance the combustion of other materials.
• Organic Peroxide materials are those that are any organic compound containing Oxygen (O) in the bivalent -O-O- structure and which may be considered a derivative of hydrogen peroxide, where one of more of the hydrogen atoms have been replaced by organic radicals.

Class 4: Flammable Solids, Spontaneously Combustible Materials and Dangerous When Wet material are defined as follows:

• Flammable Solids are types of solid material that
   become flammable in different environments. It is
   defined by three separate categories:
   (1) desensitized explosives which are wetted with
   sufficient water, alcohol, or plasticizer to suppress
   explosive properties;
   (2) self-reactive materials that can undergo a
   strongly exothermic decomposition even without
   participation of oxygen (air); and
   (3) readily combustible solids.
• Spontaneously Combustible Materials are those
   materials exhibiting pyrophoric or of self-heating
   properties that can ignite without any external fuel
   source when exposed to the air.
• Dangerous When Wet Materials are materials that,
   by contact with water, are liable to become
   spontaneously flammable or to give off flammable or
   toxic gas at a rate greater than 1 L per kilogram of
   the material, per hour.

Class 3: Flammable and Combustible liquids are defined as follows:

• Flammable liquids are liquids having a flash point of
   not more than 60.5 °C (141° F), or any material in a
   liquid phase with a flash point at or above 37.8° C
   (100° F) that is intentionally heated and offered for
   transportation or transported at or above its flash
   point in a bulk packaging, with exceptions.
• Combustible liquids:
   (1) are liquids that do not meet the definition of any
   other hazard class and have a flash point above
   60.5° C (141° F) and below 93° C (200° F);
   (2) are flammable liquids with a flash point at or
   above 38° C (100° F) that do not meet the definition
   of any other hazard class may be reclassed as a
   combustible liquid. This provision does not apply to
   transportation by vessel or aircraft, except where
   other means of transportation is impracticable;
   (3) that do not sustain combustion are not subject to
   the requirements of this subchapter as a
   combustible liquid.

Class 2: Flammable Gas, Non-flammable Compressed Gas, and Poisonous Gas are defined as follows:

• Flammable gases are any materials that are gases
   at 20o C (68° F) or less and 101.3 kPa (14.7 psia)    of pressure and are ignitable when in a mixture of
   13 percent or less by volume with air or have a    flammable range with air of at least 12 percent    regardless of the lower limit.
• Non-flammable Compressed gases are any
   gaseous materials that do not meet the definition of
   Division 2.1 or 2.3
• Poisonous Gases are materials that are gases at
   20o C (68° F) or less and 101.3 kPa (14.7 psia) of
   pressure and are known to be so toxic to humans as
   to pose a hazard to health during transportation.

Class 1: Explosives are defined as follows:

• any substance or article, including a device, which is
   designed to function by explosion (i.e., an extremely
   rapid release of gas and heat) or which, by chemical
   reaction within itself, is able to function in a similar
   manner even if not designed to function by
   explosion, unless the substance or article is
   otherwise classed under the provisions of this
   subchapter. The term includes a pyrotechnic
   substance or article, unless the substance or article
   is otherwise classed under the provisions of this
   subchapter.

Other Regulated Materials (ORM-D): a material such as a consumer commodity, which, although otherwise subject to the regulations of this subchapter (C), presents a limited hazard during transportation due to its form, quantity and packaging. It must be a material for which exceptions are provided in the § 172.101 table. Each ORM-D material and category of ORM-D material is listed in the § 172.101 table.

Introduction, cont.

The nine hazard classes and ORM-D defined in the HMR and considered capable of posing an unreasonable risk to health, safety, and property when transported in commerce are identified here. Click on an image to learn more. When you are finished reviewing the information, please select NEXT to continue the training.