Organic peroxides are organic compounds containing the peroxide functional group (ROOR'). If the R' is hydrogen, the compound is called an organic hydroperoxide. Peresters have general structure RC(O)OOR. The O-O bond easily breaks and forms free radicals of the form RO·. Thus, organic peroxides are useful as initiators for some types of polymerisation, such as the epoxy resins used in glass-reinforced plastics. MEKP and benzoyl peroxide are commonly used for this purpose. However, the same property also means that organic peroxides can either intentionally or unintentionally initiate explosive polymerisation in materials with unsaturated chemical bonds, and this process has been used in explosives. Organic peroxides, like their inorganic counterparts, are powerful bleaching agents.
| Height |
4" |
| Width |
4" |
| >Size |
4"h x 4"w |
| Wording |
ORGANIC PEROXIDE 5.2
|
| Language |
English |
| Reflectivity |
Non-Reflective |
| Glow |
Non-Glow |
| Color |
BLACK / YELLOW
|
| Hazard Class |
5 Oxidizing Agents and Organic Peroxides |
Link for the Electronic Code of Fedural Regulations for Non-Flammable D.O.T. Label
very often referred to as an Accuform brand with the part number of MSL201EV5
Division 5.2: Organic Peroxides
An organic peroxide is any organic compound containing oxygen (O) in the bivalent -O-O- structure and which may be considered a derivative of hydrogen peroxide, where one or more of the hydrogen atoms have been replaced by organic radicals, unless any of the following paragraphs applies:
- The material meets the definition of an explosive as prescribed in subpart C of this part, in which case it must be classed as an explosive;
- The material is forbidden from being offered for transportation according to 49CFR 172.101 of this subchapter or 49CFR 173.21;
- The Associate Administrator for Hazardous Materials Safety has determined that the material does not present a hazard which is associated with a Division 5.2 material; or
- The material meets one of the following conditions:
-
- For materials containing no more than 1.0 percent hydrogen peroxide, the available oxygen, as calculated using the equation in paragraph (a)(4)(ii) of this section, is not more than 1.0 percent, or
- For materials containing more than 1.0 percent but not more than 7.0 percent hydrogen peroxide, the available oxygen content (Oa) is not more than 0.5 percen
This transportatioin label indicates that solid substances will emit a flammable gas when wet or react violently with water. Some of the items that you need to take into consideration when you are transporting them are sodium, calcium, potassium and calcium carbide. This is not an all inclusive list but a good standard to check yourself against. 4.3 Dangerous when Wet: Solid substances that emit a flammable gas when wet or react violently with water (sodium, calcium, potassium, calcium carbide (Calcite))
| Class 5 Packing Groups |
| Group | Division | Phase | Details |
| Group I |
5.1 |
Solid |
Any material which, in either concentration tested, exhibits a mean burning time less than the mean burning time of a 3:2 potassium bromate/cellulose mixture. |
| Group II |
5.1 |
Solid |
Any material which, in either concentration tested, exhibits a mean burning time less than or equal to the mean burning time of a 2:3 potassium bromate/cellulose mixture and the criteria for Packing Group I are not met. |
| Group III |
5.1 |
Solid |
Any material which, in either concentration tested, exhibits a mean burning time less than or equal to the mean burning time of a 3:7 potassium bromate/cellulose mixture and the criteria for Packing Group I and II are not met. |
| Group I |
5.1 |
Liquid |
Any material which spontaneously ignites when mixed with cellulose in a 1:1 ratio; or
Any material which exhibits a mean pressure rise time less than the pressure rise time of a 1:1 perchloric acid (50 percent)/cellulose mixture. |
| Group II |
5.1 |
Liquid |
Any material which exhibits a mean pressure rise time less than or equal to the pressure rise time of a 1:1 aqueous sodium chlorate solution(40 percent)/cellulose mixture and the criteria for Group I are not met. |
| Group III |
5.1 |
Liquid |
Any material which exhibits a mean pressure rise time less than or equal to the pressure rise time of a 1:1 nitric acid (65 percent)/cellulose mixture and the criteria for Packing Group I and II are not met. |
| Group II |
5.2 |
All |
All Division 5.2 materials are assigned to Packing Group II in Column 5 of the 49 CFR 172.101 Table. |
Organic peroxides find numerous applications, often involving similar chemistry. Thus, peroxides serve as accelerators, activators, cross-linking agents, curing and vulcanization agents, hardeners, polymerisation initiators, and promoters. Drying oils, as found in many paints and varnishes function via the formation of hydroperoxides.
Methyl ethyl ketone peroxide, benzoyl peroxide and to a smaller degree acetone peroxide are used as initiators for radical polymerization of some resins, e.g. polyester and silicone, often encountered when making fiberglass.
Bleaching and disinfecting agents
Benzoyl peroxide and hydrogen peroxide are used as bleaching and "maturing" agents for treating flour to make its grain release gluten easier; the alternative is letting the flour slowly oxidize by air, which is too slow for the industrialized era. Benzoyl peroxide is an effective topical medication for treating most forms of acne.
In the synthesis of organic compounds
Many organic compounds are prepared using peroxides, most famously epoxides from alkenes. Tert-butyl hydroperoxide (TBHP) is an organic-soluble oxidant employed in a variety of metal-catalyzed oxidations, such as the Halcon process (to give propylene oxide) and the Sharpless epoxidation.
Explosives
Acetone peroxide is an ingredient in explosive for paramilitaries because of its ease of manufacture, despite its instability. It is notorious for its susceptibility to heat, friction, and shock.[3] HMTD is another widely-known explosive organic peroxide.
