Global Unified Classification of Organic Peroxides in Hazardous Chemicals
(1) Definition
Organic peroxides are liquid or solid organic compounds containing an -O-O- structure where one or both of the hydrogen atoms of the peroxide have been replaced by organic groups. This term also includes formulations (mixtures) of organic peroxides. Organic peroxides are thermally unstable substances or mixtures that can undergo exothermic self-accelerating decomposition. Additionally, they may exhibit one or more of the following properties:
- Explosive decomposition
- Rapid combustion
- Sensitive to impact or friction
- React dangerously with other substances
In laboratory experiments, organic peroxides are considered to possess explosive properties when they exhibit deflagration, rapid decomposition, or violent effects under limited conditions during formulation. Organic peroxides containing organic materials with not more than 1.0% hydrogen peroxide and having an available oxygen content not exceeding 1.0%, or with more than 1.0% but not more than 7.0% hydrogen peroxide and an available oxygen content not exceeding 0.5%, need not be classified as organic peroxides.
(2) Classification
-A Type: Explosive upon heating
Any mixture of organic peroxides, when packaged and capable of deflagration or detonation, shall be classified as Organic Peroxide Type A.
-B Type: Combustible or explosive upon heating
Any mixture of organic peroxides that is combustible, packaged and not capable of deflagration or detonation, but is liable to undergo thermal explosion within the package shall be classified as Organic Peroxide Type B.
-C and D Type: Combustible upon heating
Any organic peroxide that is explosive, but when the substance or mixture cannot deflagrate or detonate or undergo thermal explosion within the package shall be classified as Organic Peroxide Type C. Any organic peroxide exhibiting the following characteristics during laboratory testing shall be classified as Organic Peroxide Type D:
Deflagrates partially when heated in a closed vessel, does not deflagrate rapidly and does not exhibit violent effects; or
Does not deflagrate or detonate when heated in a closed vessel and exhibits slow deflagration without exhibiting violent effects; or
Does not deflagrate or detonate when heated in a closed vessel and exhibits moderate effects.
-E and F Type: Combustible upon heating
Any organic peroxide that does not deflagrate or detonate when heated in a closed vessel during laboratory testing, exhibits little or no effect, or is of low or no explosive power shall be classified as Organic Peroxide Type E. Any organic peroxide that does not deflagrate or detonate when heated in a closed vessel under a flowing gas condition during laboratory testing, exhibits little or no effect, and is of low or no explosive power shall be classified as Organic Peroxide Type F.
-G Type: No applicable labeling criteria
Any organic peroxide that does not deflagrate or detonate when heated in a closed vessel under a flowing gas condition during laboratory testing, exhibits no effect and has no explosive power, provided it is thermally stable (with a self-accelerating decomposition temperature of 60°C or higher for a 50 kg package) and for liquid mixtures, the diluent used for desensitization has a boiling point not lower than 150°C, shall be classified as Organic Peroxide Type G.[/vc_column_text][/vc_column][/vc_row]
