An organic peroxide is an organic compound with two oxygen atoms joined together. Benzonyl peroxide and hydrogen peroxide, commonly used as bleaching and maturing agents for treating flour, are two examples. The Australian Dangerous Goods Code provides the official definition for "organic peroxides". The definition is as follows:
Division 5.2 Organic peroxides
Organic substances which contain the bivalent -0-0- structure and may be considered derivatives of hydrogen peroxide, where one or both of the hydrogen atoms have been replaced by organic radicals. 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.
How do oxidising agents and organic peroxides differ
Oxidising agents are substances which can oxidize other substances. The oxidising process can create heat, fires and gas. Organic peroxides are good oxidising agents, but the risks they present are not identical. Oxidising agents are non-combustible and simply provide the oxygen needed to sustain combustion. Organic peroxides, on the other hand, may combust independently. While this is a notable difference, both oxidising agents and organic peroxides should be handled and stored carefully just the same.
The risks of Organic Peroxides
Organic peroxides are by nature relatively unstable. They are sensitive to heat and therefore prone to decomposition by burning. Under certain circumstances such as high temperatures and inadequate segregation from incompatible substances, organic peroxides can ignite and cause uncontrollable fires. The risk of fires from organic peroxides is extremely unsafe, but it isn't the only way that these substances can cause damage to people and property.
Risk to people
When organic peroxides ignite they can burn and suffocate people in the area of ignition. However, even without the presence of flames, organic peroxides are often highly toxic and particularly irritating to your skin, eyes, and mucous membranes. If you attempt to handle organic peroxides without the aid of appropriate personal protective equipment, bodily injuries will be obtained, especially if emergency eyewash stations and safety showers are not immediately available.
Risk to property
Organic peroxides can also be very hazardous to property. Some organic peroxides are corrosive, which means that they can attack and destroy metals. Methyl ethyl ketone peroxide (MEKP) is an organic peroxide used to incite polymerization in the production of polyester and acrylic resins. If handled incorrectly, MEKP presents an extreme risk of explosion. If MEKP comes into contact with water or moist air it will release irritating gases. This seemingly minor event can cause a blast that can damage equipment, machinery or an entire plant. Such an event would cause setbacks in work and huge monetary losses for the company.
Organic peroxide Storage Standards
The Australian Standards set out the minimum requirements for compliant storage and handling of dangerous goods. These standards have been developed to promote a high level of safety for people, property and the environment where dangerous goods are stored and handled. The standard that specifies the requirements for compliant storage and handling of organic peroxides is AS2714-2008 - The storage and handling of organic peroxides.
How to Store Organic Peroxides
Heat, friction, mechanical shock or contact with incompatible substances can cause rapid and explosive decomposition in organic peroxides. However, these severe chemical reactions can be avoided by utilising safe and compliant organic peroxide storage cabinets that adhere to the Australian Standard AS2714-2008.
A compliant organic peroxide indoor storage cabinet would have double-walled steel construction on all sides, each wall being a minimum of 0.75mm thick. There must also be at least a 40mm space in between walls, which may be an open air space or filled with non-combustible insulation. The door of the cabinet must be self-closing and close fitting, with either a friction or magnet type lock that can automatically release should there be a buildup of pressure inside the cabinet. Door catches and hinges should be made of metal and not plastic. Shelves, meanwhile, need to be perforated for free air movement and able to carry the maximum possible load. In order to contain any potential leakage, the inner base of the storage cabinet must form a liquid-tight compound at least 150mm deep.
Overall, a storage cabinet for organic peroxides should be sturdy and protect its contents from combustion or decomposition, whether it be gradual or sudden. It is also vital to ensure that the cabinet is located at least 3 meters from any ignition source and near an external wall of the building. It is also important to ensure that the cabinet is not located in an area that will obstruct emergency escape routes.
Organic peroxides have the potential to be extremely useful, but they can also be very harmful to people, property and the environment. To find out more about how to segregate organic peroxides from other incompatible dangerous goods, click on the image below 👇.