Organic Peroxides

As planned, we would like to continue with information concerning the Hazard Classes and divisions. In May we discussed Div. 5.1, Oxidizers and in June we did a recap of classes 1 and 2 and reminded you about certain approvals and exemptions issued by the U.S. D.O.T., Research and Special Programs Administration (RSPA). We also reminded you that the U.S. has added severe restrictions on oxygen cylinders, Div. 2.2, sub risk 5.1.

This month we would like to direct your attention to Organic Peroxides, Division 5.2. Are you ready?

The official definition is: Organic substances which contain the bivalent structure -O-O- and may be considered derivatives of hydrogen peroxide in which one or both of the hydrogen atoms have been replaced by organic radicals.

Note: Hydrogen peroxide is made up of two hydrogen atoms and two oxygen atoms connected by in a chain thusly: H-O-O-H.

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.

You might want to ask your average truck driver, cargo handler, cargo agent, warehouse distribution worker or enforcement officer exactly what all that means.

It gets better! The "Experts" then go on to say that an organic peroxide must be classified as an organic peroxide unless the organic peroxide formulation contains:

• Not more than 1.0% available oxygen from the organic peroxides when containing nor more than 1.0% hydrogen peroxide, or
• Not more than 0.5% available oxygen from the organic peroxides when containing more than 1.0% but not more than 7.0% hydrogen peroxide.

Additionally there are formulae to help determine percentages.
All extremely enlightening.

In the above noted definition of Organic Peroxides, Div. 5.2 the phrase "hydrogen peroxide" appears four times. The phrase "organic peroxide" appears six times. Both phrases are matched together four times.

The hazmat tables list "Hydrogen Peroxide" (in varying percentages) 6 times - a 7th time as another compound. Five out of the seven times the "Hydrogen Peroxide" is classified as Div. 5.1 (Oxidizer) with a sub risk of 8 (Corrosive). Of the other two entries, one classifies "Hydrogen Peroxide" as an Oxidizer (5.1) and the other entry is "not restricted" (not regulated).

Are you confused? Wait, there is more....

There are 20 entries in the hazmat tables for "Organic Peroxides" - some solid; some liquids; some temperature controlled; eight are allowed to be shipped by air; 16 are forbidden by air; some require explosive labels as subsidiary risk labels; some require corrosive labels as the subsidiary risk labels. All of the entries in the tables have proper shipping names starting off with "Organic peroxides type ___".

Appendix C in the IATA Regulations, in the Table C-2, lists approximately 200 combinations of mixtures of organic peroxides, with percentages of the organic peroxide and other factors that determine which Proper Shipping Name and UN I.D. Number to use in the Dangerous Goods List (Hazmat Table). Caution: the print is small so use a ruler to make sure you are reading the entry correctly. D.O.T., IMO, I.C.A.O., and the UN Orange Book have similar tables.

That is a lot of technical information. And it makes it difficult for the average person to understand exactly what an organic peroxide is or just how dangerous it can be.
First of all, by air, very small quantities of the few 5.2 materials that are even allowed to go by air are allowed per package. That ought to be an indication that you are dealing with something that is pretty dangerous.

Lets take another look at the properties of an organic peroxide:

• Be liable to explosive decomposition:
  We would guess that most of our readers can conjure up a vision of a violent explosion. Sort of like hell, fire, and brimstone! Only, a lot faster!
• Burn rapidly
  Gasoline burns rapidly. Can you possibly imagine a chemical that is not a flammable liquid that could burn as rapidly as gasoline?
• Be sensitive to impact or friction
  Imagine, if you will, a warm bottle of soda (sometimes called "pop"). Drop it or shake it and we all know that when the bottle cap (closure) is removed the contents will rapidly shoot out of the bottle. The soda is not an organic peroxide but that carbonated beverage surely reacts in a similar fashion, splashing out of the bottle with considerable force. Of course, if the organic peroxide that rapidly splashes out of the bottle happens to be the type that is liable to explosive decomposition, or burns rapidly or can burn the eyes - watch out!
• React dangerously with other substances
  Most adults understand that when you mix a hippochlorite solution (chlorine solution or laundry bleach) and ammonia solution (household cleaning agent) together they form a toxic gas that can immobilize a person and possibly cause death. That gives you some idea of what the experts mean when they refer to chemicals that react dangerously. However, different combinations of chemicals result in different dangerous reactions. Organic peroxides mixed with a very large number of other chemicals causes either an explosion or a heat buildup and subsequent fire or forms a corrosive and flammable reaction or creates a corrosive and toxic gas.
• Cause damage to the eyes
  With all those properties listed above its no wonder that organic peroxides can cause damage to the eyes. Think about "Hydrogen Peroxide Solution" that may be in your medicine cabinet at home. When you pour it on a cut or an infection it bubbles up or foams and stings the wound pretty badly. Although that product is more likely to be and oxidizer or a non-regulated item (usually a 3% solution) it sure does "burn" or "sting" the affected area. And the consumer information on that bottle always cautions you to keep it out of sunlight, away from heat, do not drop, and do not open the bottle near your face. If that little bottle is so dangerous
  imagine what a commercial-grade organic peroxide can do.

So, in normal language, an organic peroxide is a very sensitive, unstable, radical type of chemical that can cause an explosion or a very rapid type of fire and can quickly build up pressure in containers causing a sometimes violent reaction and can react very dangerously with other chemicals and burn the skin and the eyes. Because of the possibility of rapidly building pressure in the container due to heat or vibration, the containers frequently are vented to allow the excess pressure to vent into the atmosphere. These types of containers are forbidden in air transportation.

And, they are not easy to identify because the normal methods of looking up hazardous materials in the transportation regulations are not used to identify them.

Now, wasn't that easy?

Organic peroxides are used in cosmetics (blemish removers), rocket fuel, explosives, plastics and fibreglass, fibreglass repair kits (for boats and aircraft), chemical testing kits, first aid kits, anti-bacterial and anti-viral cleaning agents, and many other uses.

To an untrained shipper or distributor they are sometimes shipped as undeclared dangerous goods because they are not identified by normal procedures. Of course, if you read the MSDS carefully, you might get a hint.