Class 5 Hazards

Class 5 Hazard involves oxidizing substances and organic peroxides. There are 2 sub-divisions: 

  1. Oxidizing Agents
  2. Organic Peroxides

5.1 Oxidizing Agents 

Oxidizing agent is a substance which in itself is not necessarily combustible, but due to high content oxygen it may get reactive with other flammable or combustible materials, and cause combustion. The agents have the ability to provide excessive amounts of oxygen to enrich flammable and combustible substances causing them to ignite at much lower temperature.

Such fires are difficult to extinguish by powder or foam, as the oxygen is already present in the agent. Some oxidizers can be explosive if heated strongly, particularly in the presence of carbon. Ammonium nitrate mixed with hydrocarbon oil, e.g., diesel, becomes a powerful explosive, much used in the extractive industries, and by terrorists.

Note: At least keep 5 meters away from flammable and combustible substances from oxidizing agents.

E.g.: Nitric acid (HNO3), Potassium Chlorate (KClO3)

5.2 Organic Peroxides 

An organic peroxide is any organic compound containing oxygen (O) in the bivalent -O-O- structure and which may be considered a derivative of hydrogen peroxide, where one or more of the hydrogen atoms have been replaced by organic radicals.

They often have to be maintained at maximum storage temperature less than 38°C (100°F) but the supplier may recommend a lower temperature for specific organic peroxides.

Some organic peroxides must be kept at low temperatures in refrigerators or freezers to keep them inactive and temperature must be carefully controlled. 

Otherwise, if they exceed a certain temperature specific to the material, they will start to decompose rapidly, similar to the self-reactive materials in Class 4.1, resulting in uncontrollable progress towards fire or explosion. Because of their reactive nature, they can be damage to the human body, particularly the eyes. Peroxides are also strong oxidizers and easily react with skin, cotton and wood pulp.

Note: Keep them away from incompatible materials such as strong acids and bases, other oxidizing materials, flammable or combustible liquids and materials that can be oxidized (often called reducing materials or agents).

E.g.: Acetozone, Ethyl hydroperoxide