Oxidising Substances and Organic Peroxides

CLASS 5 - OXIDISING SUBSTANCES & ORGANIC PEROXIDES

Note: The following description is not intended to be a definitive technical description of what is termed a dangerous goods under the New Zealand Standard 5433:1999 - Transport of Dangerous Goods on Land or The United Nations Recommendations on the Transport of Dangerous Goods.

Flammability is the principle hazard in the transportation of dangerous goods. In consequence, chemicals which will accelerate combustion are also considered to be hazardous.
Examples of Oxygen Sources are:

Sodium Chlorate
Hydrogen Peroxide
Methyl Ethyl Ketone
Sodium Sulphite

Oxidizers are chemicals which contain one or more oxygen atoms which are readily available for reaction with other chemicals. The simplest oxidizer is of course oxygen itself. Others can be identified with the chemical family suffix of "ite" or "ate".

Oxidizers may not be particularly hazardous on their own. They require some other event or condition such as a chemical reaction or fire (which is of course only a particular kind of chemical reaction) for their hazard to be realised.

However, they may quite "corrosive" particularly where moisture is available. This is probably not enough to make them a class 8 hazardous material, but will be extremely irritating to any person attempting to handle the material without proper protective clothing.

Organic peroxides are unique in dangerous goods because this particular hazard class is a specific chemical family. Substances which contain the bivalent structure -O-O- are known as organic peroxides. They may be considered derivatives of hydrogen peroxide in which one or both of the hydrogen atoms have been replaced by organic radicals. Hydrogen peroxide is made up of two hydrogen atoms and two oxygen atoms connected in a chain: H-O-O-H.

Organic peroxides are thermally unstable substances which may undergo exothermic, self-accelerating decomposition. In addition, they may have one or more of the following properties:

be liable to explosive decomposition;
burn rapidly;
be sensitive to impact or friction;
react dangerously with other substances;
cause damage to the eyes.