(1) Definition

Organic peroxides refer to liquid or solid organic compounds containing derivatives with - O-O - structure and one or two hydrogen atoms of hydrogen peroxide can be considered to have been replaced by organic groups. The term also includes Organic peroxides formulations (mixtures). Organic peroxides are thermally unstable substances or mixtures that can undergo exothermic self accelerating decomposition. In addition, they can have one or more of the following properties:

1) Easy to explode and decompose.

2) Fast burning.

3) Sensitive to impact or friction.

4) Hazardous reactions with other substances.

In laboratory tests, Organic peroxides are considered explosive when they are prone to deflagration, rapid burst or severe effects when heated under limited conditions.

When organic matter contains no more than 1 The available oxygen of Organic peroxides at 0% hydrogen peroxide is not more than 1 0%, or the available oxygen of Organic peroxides containing more than 1.0% but not more than 7.0% hydrogen peroxide is not more than 0 5%, which may not be included in the classification of Organic peroxides.

(2) Classification

——Type A can cause explosion when exposed to heat

Any Organic peroxides mixture, packaged and capable of rapid deflagration or sudden combustion, will be classified as Organic peroxides type A.

——Type B can cause combustion or explosion when exposed to heat

Any Organic peroxides mixture with flammability, packaged, neither deflagration nor rapid burst, but easy to occur in the package of thermal explosion will be classified as Organic peroxides type B.

——C-type and D-type burn when exposed to heat

Any Organic peroxides with explosive properties will be classified as Organic peroxides type C when the substance or mixture cannot deflagrate or burst rapidly or thermal explosion occurs according to the packaging. Any Organic peroxides that has one of the following conditions in the laboratory test will be classified as Organic peroxides type D:

1) Partial deflagration, non rapid sudden ignition, and non display of severe effects when heated under closed conditions; or

2) When heated under closed conditions, there is no significant impact of deflagration, slow sudden ignition, and no display; or

3) When heated in a sealed environment, non deflagration or sudden ignition has a moderate impact on the display.

——E-type and F-type burn when exposed to heat

In laboratory tests, any Organic peroxides that neither deflagrates nor bursts when heated under closed conditions and shows little or no influence will be classified as Organic peroxides type E; In the laboratory test, any Organic peroxides that does not deflagrate or burst under the airflow state when heated under closed conditions, only shows small or no effect and low or no explosive force will be determined as Organic peroxides type F.

——G type without applicable label elements

In the laboratory test, any Organic peroxides will not deflagrate or burst, show no influence and have no explosive force in the air flow state when heated under closed condition, provided that it is thermally stable (the self accelerating decomposition temperature of 50 kg package is 60 ℃ or higher), and for liquid mixture, the diluent used for desensitization has a boiling point of not less than 150 ℃, it will be determined as Organic peroxides type G. If the mixture is not thermally stable or the boiling point of diluent used for desensitization is lower than 150 ℃, the mixture shall be determined as Organic peroxides type F.

The available oxygen content (X) of Organic peroxides mixture can be calculated by formula (3-2).

(3-2) where ni is the number of peroxide groups of Organic peroxides i per molecule;

Ci - mass fraction of Organic peroxides i;

Mi - relative molecular weight of Organic peroxides i.

(3) Hazard pictogram of Organic peroxides