The IMDG code includes several classifications, each of which describes the regulations for a different hazardous material. IMDG classes encompass various forms of matter, such as liquids, gases and solids. They also categorize materials by types of risk, such as explosives and radioactive materials. The IMDG classifications include the following.
Classification 1: This classification is for explosive materials. It has multiple subdivisions, depending on the level of risk each substance poses. The highest-risk materials have the strictest transportation guidelines. Examples include fireworks, rockets, ammunition and airbag inflators.
Classification 2: These guidelines are for gaseous substances. It has subsections for gases that are flammable, not flammable and neither flammable nor toxic. Gases include Freon, propane and aerosols.
Classification 3: This category is for liquids. It contains guidelines for transporting any dangerous liquid types, such as alcohol, varnish or gasoline.
Classification 4: This category is for solids. It has three subsections. The first is for combustible solids, the second for self-reactive solids and the third for solids that emit toxic gases when they come in contact with water. Some examples include phosphorus, matches and metal powders.
Classification 5: This classification deals with any materials that could oxidize, such as chemical oxygen generators or hydrogen peroxide. An oxidizing agent accepts electrons and can result in explosions and fires.
Classification 6: Classification 6 deals with toxic substances, which could contain microorganisms that can cause disease in humans or animals. Common harmful substances include medical waste and biological specimens.
Classification 7: This category is for radioactive materials, which have unstable atoms, losing energy and emitting particles as they stabilize. Some radioactive materials are uranium compounds and medical isotopes.
Classification 8: These guidelines are for corrosive and erosive materials. Corrosion is the destruction of materials through chemical reactions, while erosion is the physical wearing away of materials. Corrosive agents include oxygen and sulfates. Some corrosive or erosive materials include batteries, acids, fire extinguisher charges and formaldehyde.
Classification 9: The final classification is a catch-all for any unspecified dangerous materials, which could be anything from dry ice to internal combustion engines.