Hazard classes and packing groups

As part of the classification process, dangerous goods (DGs) are classified by type of hazard and the hazard they represent using physical/chemical properties as well as mammalian and environmental information.

  • Class 1: Explosives
  • Class 2: Gases
  • Class 3: Flammable liquids
  • Class 4: Flammable solids, substances that could spontaneously combust, and substances which, on contact with water, emit flammable gases
  • Class 5: Oxidizing substances and organic peroxides
  • Class 6: Toxic and infectious substances
  • Class 7: Radioactive material
  • Class 8: Corrosive substances
  • Class 9: Miscellaneous dangerous substances and articles, including environmental hazardous substances

Once a product has been assigned a hazard class, it will then be assigned to a packing group (PG) in accordance with the degree of danger it presents. Exceptions are made for those materials covered under Class 1, 2 and 7, divisions 5.2 and 6.2 and other than self-reactive substances of Division 4.1 (criteria largely conform to those set out in GHS).

  • Packing group I: Substances presenting high danger
  • Packing group II: Substances presenting medium danger
  • Packing group III: Substances presenting low danger

ExxonMobil Chemical fluids, plasticizers and chemical intermediates, when classified as a dangerous good, are predominantly classified as hazard class 2, 3 or 9:

  • Class 2 corresponds to gases which at 50ºC (122ºF) has a vapor pressure (VP)>300 kPa or it is completely gaseous at 20ºC (68ºF) at a standard pressure of 101.3 kPa.
  • Class 3 groups together all flammable liquids. In general, products which create a flammable vapor at temperatures of not more than 60ºC (140ºF) in closed-cup tests, or not more than 65ºC (149ºF) in open-cup test, normally referred to as the flash point (FP), are considered flammable liquids (in most regulatory schemes).
  • Class 9 corresponds to miscellaneous dangerous substances and articles, including elevated temperature substances and environmentally hazardous substances (Aquatic environment).

Environmental hazardous substances

Environmental hazardous substances (EHS) include solid or liquid substances, solutions or mixtures that are harmful to the aquatic environment. The basic elements for classification of such substances are:

  • Acute aquatic toxicity;
  • Chronic aquatic toxicity;
  • Potential for or actual bioaccumulation; and
  • Degradation (biotic or abiotic) for organic chemicals.

Additionally, when substances and articles are shipped by road (ADR Code) and by inland waterways (ADN), they are assigned a specific Classification Code according to their hazardous properties. For example:

Class 3:

  • F - Flammable liquids, without subsidiary risk and articles containing such substances:
  • F1 - Flammable liquids having a FP ≤ 60ºC;
  • F2 - Flammable liquids having a FP > 60ºC which are carried or handled over for carriage at or above their FP (elevated temperature substances)
  • F3 - Articles containing flammable liquids.

Class 9:

  • M1 - Substances which, on inhalation as fine dust, may endanger health;
  • M6-M8 - Environmentally Hazardous Substances (EHS):
  • M6 - Pollutant to the aquatic environment, liquid;
  • M7 - Pollutant to the aquatic environment, solid;
  • M8 - Genetically modified microorganisms and organisms;

For more information on classes and packing groups, please click here.

Page glossary

  • Acute
  • ADN
  • ADR
  • Bioaccumulation
  • Chronic
  • Classification
  • Corrosive
  • Flash Point
  • GHS
  • Hazard
  • Inhalation
  • Medium
  • Plasticizers
  • Risk
  • Subsidiary Risk
  • Toxicity
  • VP