The Chemical Properties of Benzoyl Peroxide Concerning Transportation
Benzoyl Peroxide is commonly found as a white granular tasteless and odorless flammable solid that is used as a bleaching agent for flour, fats, waxes, and oils, as a polymerization catalyst, and in pharmaceuticals; such as the treatment for acne. Benzoyl peroxide can also be found as a paste that is non-shock sensitive, more difficult to ignite and is generally non-separating. Benzoyl Peroxide goes by many different names. Benzoyl Peroxide is also known as dibenzoyl peroxide, benzoyl superoxide, debroxide, panoxyl, lucidol, and many other names. It can be stored at room temperature for long periods of time; however, benzoyl peroxide that is not confined will decompose and its decomposition is explosive.
Benzoyl Peroxide is classified by the DOT as an organic peroxide. This DOT class is division 5.2. The DOT class 5.2 would require an “Organic Peroxide” label. Information on the shipping label would include:
* Proper shipping name: Benzoyl peroxide
* Hazard class or division: 5.2
* Identification number: NA2085 (with no other specification); UN2085
According to the DOT Emergency Response Guide, the primary hazard for benzoyl peroxide is that it may explode from heat, shock friction or contamination. This is also further supported by the Dangerous Properties of Industrial Material which describes Benzoyl Peroxide has a dangerous explosion hazard and may explode spontaneously when heated above it’s melting point which is 106-108.6 degrees Celsius. When it is above 103 degrees Celsius the product decomposes and forms flammable products. In a fire situation that is not in an isolated confined space, I believe that the primary hazard is the corrosive and toxic gases that are emitted.
The formula for benzoyl peroxide is (C6H5CO)2O2. The physical properties of benzoyl peroxide are as follows:
MP: 106-108.6oF
BP: Ignites or decomposes explosively at or above 176oF (80oC)
Specific Gravity (solid): 1.334 at 59oF (15oC)
Molecular Weight: 242.2
Vapor Pressure: 0.1 mm Hg at 68oF (20oC)
Solubility: less than 1g/100g water at 68oF; soluble in benzene, acetone, ether, chloroform, and nearly all other organic solvents
Auto-ignition Temperature: 176oF (80oC)
Benzoyl peroxide is incompatible with combustible materials such as wood and paper. Benzoyl peroxide has an explosive or violent reaction on contact with N, N-dimethylaniline, aniline, dimethyl sulfide, lithum tetrahydroaluminate, and N-bromosuccinimide + 4 toluic acid. Benzoyl peroxide when mixed with carbon tetrachloride + ethylene explodes at elevated temperatures and pressures. Benzoyl peroxide also reacts violently with various organic or inorganic acids, alcohols, amines, metallic naphthenates, dimethylaniline, and (CCl4 + C2H4). Benzoyl peroxide reacts violently when it comes in contact with charcoal that is heated above 50 degrees Celcius.
In emergency response situations a positive pressure self-contained breathing apparatus (SCBA) and chemical protective clothing that is specifically recommended by the manufacturer should be worn according to the Emergency Response Guide. Fire Fighter protective clothing will only have limited protection. All precautions to prevent fire and explosion must be taken.
To fight a fire with involved benzoyl peroxide, use water spray or foam. Other extinguishing agents that may also be used are carbon dioxide, dry chemical, but it is preferable to use copious amounts of water. It should be noted that Benzoyl peroxide is insoluble with water and more dense than water so it sinks in water. If a spill occurs the emergency personnel should proceed with caution. The area should be isolated for at least 250 meters (800 feet). The substance should be prevented from entering sewers and confined spaces. Water treatment authorities should be notified. Spark-proof and explosion-proof tools should be used. Benzoyl peroxide should be handled in as little quantities as possible. All handling equipment should be grounded.
One conflicting information I received was between the Emergency Action Guide and the Dangerous Properties of Industrial Material. The Emergency Action Guide says that benzoyl peroxide is slightly soluble in water by less than 1 g/100 g water at 68oF (20oC). The Dangerous Properties of Industrial Materials differs because it states that the substance is insoluble in water. Another conflicting piece of information is that some sources say that 176oF (80oC) is the boiling point and some sources say that 217 oF (103 oC) is the boiling point.
Works Cited:
Chemical Hazardous Response Information System (CHRIS)
U.S. Coast Guard. Washington: Dept. of Transportation, U.S. Coast Guard. U.S. Gov’t. Print. Off. 4 Volumes, 2nd Edition, 1991.
Emergency Action Guides. Association of American Railroads, Bureau of Explosives of
The Safety and Hazardous Materials Division. Washington DC, Association of American Railroads. 1984.
Emergency Handling of Hazardous Materials in Surface Transportation. Pueblo, CO.
Association of American Railroads, Bureau of Explosives. 1998 Edition.
Lewis, Richard J. Sr.Dangerous Properties of Industrial Materials. Irving Sax. New York:
Van Nostrand Reinhold11th Edition, 2004.
Sittig, Marshall. Handbook of Toxic and Hazardous Chemicals and Carcinogens.
Norwich, NY. Noyes Publications. 2nd Edition. 1991
