UK Regulations

Guidance Note CS 21
The Guidance Note covers formulations which have a peroxide concentration greater than or equal to 10%.

For the purpose of the Guidance Note, packaged peroxides are divided into four flammability types. Advice on the flammability types can be obtained from the Health and Safety Executive (HSE).

Organic Peroxides Classification
Type 1 : Explosive labeled packaged peroxides and packaged peroxides which burn
very intensely
Type 2 : Packaged peroxides which burn in a way which is intermediate between types 1 and 3
Type 3 : Packaged peroxides which burn in the range "gently" up to something akin to hydrocarbon solvents
Type 4 : Packaged peroxides which are noncombustible and from which the available oxygen is not more than 5%

Location of the storage
Safety distances between organic peroxides storage and sensitive facilities (occupied buildings, storage and plants) depend on the "store area" and the type of the peroxide. These recommended safety distances are for storage holding more than 150 kg and may be reduced if suitable protective measures are employed.

Safety conditions depend on the type of the organic peroxide and the amount stored.

1st category : quantities up to 5 kg (types 1 and 2) and up to 10 kg (type 3).
2nd category : quantities up to 150 kg (types 1 to 3). They can be stored outdoors as well as indoors with a dedicated storeroom following special safety measures.
3rd category : quantities over 150 kg . Minimum separation distances from organic peroxides storage to boundaries and sensitive facilities are recommended.