Benzoyl peroxide
IUPAC name	Dibenzoyldioxidane
Molecular formula	(C6H5CO)2O2 or C14H10O4
Molar mass	242.23 g/mol
CAS number	94-36-0
Density	1.334 g/cm3
Solubility	Poor
Melting point	103–5 °C decomp. Image File history File links Download high-resolution version (1100x553, 32 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Benzoyl peroxide ... IUPAC nomenclature is a system of naming chemical compounds and of describing the science of chemistry in general. ... A chemical formula is a concise way of expressing information about the atoms that constitute a particular chemical compound. ... Molar mass is the mass of one mole of a chemical element or chemical compound. ... CAS registry numbers are unique numerical identifiers for chemical compounds, polymers, biological sequences, mixtures and alloys. ... For other uses, see Density (disambiguation). ... Solubility is a chemical property referring to the ability for a given substance, the solute, to dissolve in a solvent. ... The melting point of a crystalline solid is the temperature range at which it changes state from solid to liquid. ...
SMILES	c1ccccc1C(=O)OOC(=O)c2ccccc2
Hazards
EU classification	Explosive (E) Irritant (Xi)
EU Index	617-008-00-0
NFPA 704	The simplified molecular input line entry specification or SMILES is a specification for unambiguously describing the structure of chemical molecules using short ASCII strings. ... Council Directive 67/548/EEC of 27 June 1967 on the approximation of laws, regulations and administrative provisions relating to the classification, packaging and labelling of dangerous substances (as amended) is the main European Union law concerning chemical safety. ... NFPA 704 is a standard maintained by the U.S. National Fire Protection Association. ... Image File history File links NFPA_704. ... 4 1 4 OX
R-phrases	R2, R36, R43
S-phrases	(S2), S3/7, S14, S36/37/39
Autoignition temperature	80°C
RTECS number	DM8575000
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references

Tube of Basiron, a water-based 5% benzoyl peroxide preparation for the treatment of acne.

Benzoyl peroxide (IPA [ˈbɛnzəʊɪl pəˈrɒksaɪd]) is a chemical in the organic peroxide family. It consists of two benzoyl groups (benzaldehyde with the H of CHO removed) joined by a peroxide group. R-phrases are defined in Annex III of European Union Directive 67/548/EEC: Nature of special risks attributed to dangerous substances and preparations. ... S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. ... The autoignition temperature, or the ignition temperature of a substance is the lowest temperature at which a chemical will spontaneously ignite in a normal atmosphere, without an external source of ignition, such as a flame or spark. ... RTECS, also known as Registry of Toxic Effects of Chemical Substances, is a database of toxicity information compiled from the open scientific literature that is available for charge. ... The plimsoll symbol as used in shipping In chemistry, the standard state of a material is its state at 1 bar (100 kilopascals exactly). ... Image File history File linksMetadata Download high resolution version (2048x1536, 761 KB) Licensing I, the creator of this work, hereby grant the permission to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1. ... Image File history File linksMetadata Download high resolution version (2048x1536, 761 KB) Licensing I, the creator of this work, hereby grant the permission to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1. ... Articles with similar titles include the NATO phonetic alphabet, which has also informally been called the “International Phonetic Alphabet”. For information on how to read IPA transcriptions of English words, see IPA chart for English. ... A chemical substance is any material substance used in or obtained by a process in chemistry: A chemical compound is a substance consisting of two or more chemical elements that are chemically combined in fixed proportions. ... The general structure of an organic peroxide. ... Benzaldehyde (C6H5CHO) is a chemical compound consisting of a benzene ring with an aldehyde substituent. ... A peroxide is a compound containing an oxygen-oxygen single bond. ...

Uses

Benzoyl peroxide is a radical initiator. Homolytic cleavage of the weak oxygen-oxygen bond forms free radicals which trigger further reactions. For other uses, see Initiation (disambiguation). ... In chemistry, radicals (often referred to as free radicals) are atomic or molecular species with unpaired electrons on an otherwise open shell configuration. ...

Jack Breitbart of Revlon laboratories first developed Benzoyl peroxide's use for treating acne in the 1920s.^[1] It is typically placed over the affected areas in gel or cream form, in concentrations of 2.5% increasing through the usually effective 5% to up to 10%. Research suggests that 5 and 10% concentrations are not significantly more effective than 2.5% and 2.5% is usually better tolerated.^[2][3] It commonly causes initial dryness and sometimes irritation, although skin tolerance usually occurs after a week or so. A small percentage of people are much more sensitive to it and liable to suffer burning, itching, peeling and possibly swelling^[4]. It is sensible to apply the lowest concentration and build up as appropriate. Once tolerance is achieved, increasing the quantity or concentration a second time and gaining tolerance at a higher level usually gives better subsequent acne clearance. Benzoyl peroxide works as a peeling agent, increasing skin turnover and clearing pores, thus reducing the bacterial count there as well as directly as an antibacterial. Revlon (NYSE: REV) is an American cosmetics company. ...

Other common uses for benzoyl peroxide include dyeing hair, and as an active ingredient in teeth whitening systems. It is also used in the preparation of flour, and can be used as an initiator and catalyst for polyester thermoset resins (as an alternative to the much more hazardous methyl ethyl ketone peroxide). Ashlie from Lizzie McGuire, with green hair Hair coloring products generally fall into four categories: temporary, semipermanent, deposit only/demi, and permanent. ... For other uses, see Flour (disambiguation). ... Another meaning of initiator is SCSI initiator. ... It has been suggested that this article or section be merged into Catalysis. ... SEM picture of a bend in a high surface area polyester fiber with a seven-lobed cross section Polyester is a category of polymers, or, more specifically condensation polymers, which contain the ester functional group in their main chain. ... Thermosetting plastics (thermosets) refer to a range of polymer materials that cure, through the addition of energy, to a stronger form. ... Methyl ethyl ketone peroxide (MEKP) is an organic peroxide, a high explosive similar to acetone peroxide, and is quite dangerous to synthesize. ...

Adverse effects

In a 1977 study using a human maximization test, 76% of subjects acquired a contact sensitation to benzoyl peroxide. Formulations of 5% and 10% were used.^[5]

Safety

Pure benzoyl peroxide is highly flammable, explosive, toxic and a possible tumor promoter and may act as a mutagen^[6], and should be handled with care.

Diluted in an ointment, benzoyl peroxide is used as an acne treatment and the following precautions and claims pertain to this use. Attention should be paid to the safety directions provided when purchased.

In the United States, the typical concentration for benzoyl peroxide is 2.5% to 10% for both prescription and over the counter use. Benzoyl peroxide, like most peroxides, is a powerful bleaching agent. Contact with fabric (including clothing and bed linens) or hair can cause permanent color dampening almost immediately. A prescription drug is a licensed medicine that is regulated by legislation to require a prescription before it can be obtained. ... Over-the-counter (OTC) drugs are medicines that may be sold without a prescription, in contrast to prescription drugs. ... This article is about the chemical whitener. ...

Benzoyl peroxide breaks down in contact with skin, producing benzoic acid and oxygen, neither of which are significantly toxic.^[7] Benzoic acid, C7H6O2 (or C6H5COOH), is a colorless crystalline solid and the simplest aromatic carboxylic acid. ...

When applied to skin benzoyl peroxide has been shown to induce cancer, but only when used at 100% concentrations; it has not been shown to do this at the far lower concentrations used for treating acne, and at lower concentrations benzoyl peroxide has not been found to be mutagenic or carcinogenic.^{[citation needed]}

Benzoyl peroxide removes the top layer of skin, which also decreases the sun protective effect (roughly SPF 3). This can cause sunburn and premature aging if sun protection is not worn. If sun protection is used, benzoyl peroxide has effects similar to glycolic acid peels which are so-called anti-aging treatments. Sunscreen (also known as sunblock, suntan lotion) is a lotion, spray or other topical product that is supposed to protect the skin from the suns ultraviolet (UV) radiation, and which reduces sunburn and other skin damage, with the goal of lowering the risk of skin cancer. ... Glycolic acid (or hydroxyacetic acid) is the smallest α-hydroxy acid (AHA). ...

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Decomposition

The half-life of benzoyl peroxide is one hour at 92°C. At 131°C, the half-life is one minute. ^[8] Half-Life For a quantity subject to exponential decay, the half-life is the time required for the quantity to fall to half of its initial value. ...

References

1. ^ http://www.acnemedicineman.com/news/acne-treatmentswhich-one-is-right
2. ^ Mills, OH Jr; Kligman AM, Pochi P, Comite H (1986). "Comparing 2.5%, 5%, and 10% benzoyl peroxide on inflammatory acne vulgaris.". International Journal of Dermatology 25 (10): 664–667. PMID 2948929. 
3. ^ Yong, CC (1979). "Benzoyl peroxide gel therapy in acne in Singapore.". International Journal of Dermatology 18 (6): 485–488. PMID 158569. 
4. ^ Typical product information leaflets and monographs
5. ^ James J. Leyden, Albert M. Kligman (1977), "Contact sensitization to benzoyl peroxide", Contact Dermatitis 3 (5), 273–275. doi:10.1111/j.1600-0536.1977.tb03674.x
6. ^ [1]
7. ^ "Benzoyl Peroxide" section 3.1.1
8. ^ Hui Li (1998). "Synthesis, Characterization and Properties of Vinyl Ester Matrix Resins" (PDF). Retrieved on 2007-02-17.

PDF is an abbreviation with several meanings: Portable Document Format Post-doctoral fellowship Probability density function There also is an electronic design automation company named PDF Solutions. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 48th day of the year in the Gregorian calendar. ...

External links

• International Chemical Safety Card 0225
• NIOSH Pocket Guide to Chemical Hazards 0052
• IARC Monograph "Benzoyl peroxide."
• Benzoyl Peroxide as Acne Treatment Using Benzoyl Peroxide to treat Acne.
• Benzoyl Peroxide
• Information on Benzoyl Peroxide Application - Acne.org Daniel Kern's acne treatment regimen