General awareness of HAZMAT makes it clear to them that they classify hazardous materials into 9 separate classes.
Often, they may find that some of the most basic concepts in emergency response are those that they should revisit from time to time, to make sure they stay proficient. These classes are no exception. Here they shall go through the nine classes, and their subdivisions, as defined by the Emergency Response Guidebook.
Extremely insensitive articles
Class 1: Explosives - This first class is broken into 6 different divisions within itself. Each division carries a specific hazard, with explosion being the number one or most significant.
- Division 1.1 – Explosives which have a mass explosion hazard
- Division 1.2 – Explosives which have a projection hazard but not a “mass” explosion hazard
- Division 1.3 – Explosives which have a fire hazard and either a minor blast hazard or a minor projection hazard or both, but NOT a mass explosion hazard
- Division 1.4 – Explosives which present no significant hazard
- Division 1.5 – Very insensitive explosives with a mass explosion hazard.
- Division 1.6 – Extremely insensitive articles which do not have a mass explosion hazard.
Most common mistakes
This class is also broken into multiple divisions. However, only 3 are used to divide this class
Class 2: Gases - This class is also broken into multiple divisions. However, only 3 are used to divide this class. One of the most common mistakes people make when considering this class is that it covers all ‘flammable’ gases. This is not true, this class also covers our non-flammable gases and those in which that are deemed toxic, or poisonous.
- Division 2.1 – Flammable gases
- Division 2.2 – Non-Flammable, non-toxic gases
- Division 2.3 – Toxic gases
Emitting flammable gases
Class 3: Flammable and Combustible liquids - Class 3 is not broken into any further subdivisions. The class covers all liquids that pose any sort of a threat to become a fire issue. This covers liquids such as gasoline, Diesel, kerosene, and many others.
Class 4: Flammable solids; Substances liable to spontaneous combustion; Substances which, on contact with water, emit flammable gases. This class seems to cover quite a bit of ground when it breaks down into its divisions. However keep in mind, all of the hazards that are present for these materials generally point back to one thing, and that is its flammability.
- Division 4.1 – Flammable solids, self-reactive substances, and solid desensitized explosives.
- Division 4.2 – Substances liable to spontaneous combustion.
- Division 4.3 – Substances which in contact with water, emit flammable gases.
Substances and infectious substances
Class 5: Oxidizing substances and Organic Peroxides - Divided into 2 subclasses, this class generally is accompanied by a picture of an “O” on fire.
- Division 5.1 – Oxidizing substances
- Division 5.2 – Organic peroxides
Class 6: Toxic substances and infectious substances
- Division 6.1 – Toxic Substances
- Division 6.2 – Infectious Substances
Carrying fissile materials
Class 7: Radioactive Materials - There are no subdivisions for the radioactive class, however, a radioactive placard will come with extra information in the form of a Roman numeral I, II, or III, or the signal word ‘Fissile’.
- I – Extremely low levels of radiation present. A maximum of .5 mrem/hr
- II – Considered to be low levels of radiation. >.5 – 50 mrem/hr but a maximum radiation of 1 mrem/hr at one meters distance
- III – High radiation levels. >50 – 200 mrem/hr with a maximum reading of 10 mrem/hr at one meters distance
- Fissile – Applies to packages carrying fissile materials
Dry bulk sacks
Dry bulk sacks can carry solids while different types of tankers can carry the liquids and gases
Class 8: Corrosive Substances - While there are no subdivisions for this class, it is important to remember that the physical state of these materials can range from solid – to liquid, or gas, which also makes it important to point out that each phase can be transported differently.
Dry bulk sacks can carry solids while different types of tankers can carry the liquids and gases. Do not let a flat-bed trailer fools user, if the placard or hazard is identified, take it seriously.
Different mobile applications
Class 9: Miscellaneous dangerous goods/hazardous materials and articles - All of the above information can be located in the current edition (2016) of the Emergency Response Guidebook. These books have become a staple for all initial responses to hazmat incidents for years, and rightfully so. The guidebook can effectively allow users to set up their initial response tactics while keeping the crew, and the general public around the incident safe.
With the advancement of the personal computer and smartphone technology, it is also possible to use many different mobile applications to find this information and assist users in the field. Personally, I suggest any responder who may be coming in contact with hazardous materials to use the application WISER developed by the National Library of Medicine. This application includes the ERG inside of it and also includes extras like evacuation/protection zone mapping, what to look for in possible victims who may have been exposed to different materials, and possible treatments for those victims.
