Benzoyl peroxide (BPO)
|Molar mass||242.23 g·mol−1|
|Melting point||103 to 105 °C (217 to 221 °F; 376 to 378 K) decomposes|
|Main hazards||irritant, explosive|
|Safety data sheet||See: data page|
EU classification (DSD)
|R-phrases||R3, R7, R36, R43|
|S-phrases||(S2), S3/7, S14, S36/37/39|
|Flash point||80 °C; 176 °F; 353 K|
|80 °C (176 °F; 353 K)|
|Lethal dose or concentration (LD, LC):|
LD50 (Median dose)
|7710 mg/kg (mouse, oral)|
LC50 (Median concentration)
|7000 mg/m3 (mouse, 4 hr)|
|US health exposure limits (NIOSH):|
|TWA 5 mg/m3|
|TWA 5 mg/m3|
IDLH (Immediate danger
|Supplementary data page|
Refractive index (n),
Dielectric constant (εr), etc.
|UV, IR, NMR, MS|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|(: / ?)|
Benzoyl peroxide (BPO) is an health system.
- Acne treatment 1.1
- Other uses 1.2
- Side effects 2
- Synthesis, structure and physical properties 3
- References 4
- External links 5
Benzoyl peroxide (BPO) is effective for reducing the number and severity of acne lesions. BPO has a bactericidal effect on Propionibacterium acnes bacteria associated with acne and does not induce antibiotic resistance. It may be combined with salicylic acid, sulfur, erythromycin or clindamycin (antibiotics), or adapalene (a synthetic retinoid). Two common combination drugs include benzoyl peroxide/clindamycin and adapalene/benzoyl peroxide, an unusual formulation considering most retinoids are deactivated by peroxides. Combination products such as benzoyl peroxide/clindamycin and benzoyl peroxide/salicylic acid appear to be slightly more effective than benzoyl peroxide alone for the treatment of acne lesions.
Benzoyl peroxide for acne treatment is typically applied to the affected areas in gel or cream form, in concentrations of 2.5% increasing through 5.0%, and up to 10%. No strong evidence supports the idea that higher concentrations of benzoyl peroxide are more effective than lower concentrations.
Benzoyl peroxide commonly causes initial dryness and sometimes irritation, although the skin develops tolerance 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. It is sensible to apply the lowest concentration and build up as appropriate. Once tolerance is achieved, increasing the quantity or concentration and gaining tolerance at a higher level may give better subsequent acne clearance. Irritation can also be reduced by avoiding harsh facial cleansers and wearing sunscreen prior to sun exposure.
Other common uses for benzoyl peroxide include
- Bleaching hair
- Tooth whitening systems
- The preparation of bleached flour
- A initiator and catalyst for polyester thermoset resins, as an alternative to the much more hazardous methyl ethyl ketone peroxide.
- A hardener in order to start the polymerization process in resins. For instance, PMMA resins can be polymerized with benzoyl peroxide.
- Removing ink and dye stains on vinyl dolls and other playscale figures.
In the U.S., the typical concentration for benzoyl peroxide is 2.5% to 10% for both prescription and over-the-counter drug preparations that are used in treatment for acne. Higher concentrations are used for hair bleach and teeth whitening. Benzoyl peroxide, like most peroxides, is a powerful bleaching agent. Contact with fabrics or hair can cause permanent color dampening almost immediately. Even secondary contact can cause bleaching; for example, contact with a towel that has been used to wash off benzoyl peroxide-containing hygiene products.
Concentrated benzoyl peroxide is potentially explosive, and can cause fires without external ignition. The hazard is acute for the pure material, so the compound is generally used as a solution or a paste. For example, cosmetics contain only a small percent of benzoyl peroxide and pose no explosion risk.
Studies have highlighted the carcinogenic potential of benzoyl peroxide. A 1981 study from the journal Science concluded, "caution should be recommended in the use of this and other free radical-generating compounds".
In a 1977 study using a human maximization test, 76% of subjects acquired a contact sensitization to benzoyl peroxide. Formulations of 5% and 10% were used.
Synthesis, structure and physical properties
Benzoyl peroxide was the first organic peroxide prepared by intentional synthesis. It was prepared by treating benzoyl chloride with barium peroxide, a reaction that probably follows this equation:
- 2 C6H5C(O)Cl + BaO2 → [C6H5C(O)]2O2 + BaCl2
- [C6H5C(O)]2O2 → 2 C6H5CO2•
The symbol • indicates that the products are radicals; i.e., they contain at least one unpaired electron. Such species are highly reactive. The homolysis is usually induced by heating. The half-life of benzoyl peroxide is one hour at 92 °C. At 131 °C, the half-life is one minute.
Benzoyl peroxide breaks down in contact with skin, producing benzoic acid and oxygen, neither of which is significantly toxic.
- "NIOSH Pocket Guide to Chemical Hazards #0052".
- "Benzoyl peroxide". Immediately Dangerous to Life and Health.
- "WHO Model List of EssentialMedicines" (PDF). World Health Organization. October 2013. Retrieved 22 April 2014.
- Klenk, Herbert; Götz, Peter H.; Siegmeier, Rainer; Mayr, Wilfried (2005), "Peroxy Compounds, Organic",
- Simonart T (December 2012). "Newer approaches to the treatment of acne vulgaris". Am J Clin Dermatol 13 (6): 357–64.
- Seidler EM, Kimball AB (July 2010). "Meta-analysis comparing efficacy of benzoyl peroxide, clindamycin, benzoyl peroxide with salicylic acid, and combination benzoyl peroxide/clindamycin in acne". J Am Acad Dermatol 63 (1): 52–62.
- al.], edited by Brian K. Alldredge ... [et (2013). Applied therapeutics : the clinical use of drugs. (10th ed.). Baltimore: Wolters Kluwer Health/Lippincott Williams & Wilkins. p. 949.
- Stevens, Cynthia. "Oxy10 for vinyl stains. Benzoyl Peroxide removes stain from Vinyl. Restore Dolls". Prilly Charmin Dolls. Retrieved 9 February 2015.
- Bojar, RA; Cunliffe, William; Holland, KT (1995), "The short-term treatment of acne vulgaris with benzoyl peroxide: effects on the surface and follicular cutaneous microflora.", Br J Dermatol 132: 204–8,
- Cartwright, Hugh (17 March 2005). "Chemical Safety Data: Benzoyl peroxide". Oxford University. Retrieved 13 August 2011.
- "Skin tumor-promoting activity of benzoyl peroxide, a... [Science. 1981] - PubMed - NCBI". Ncbi.nlm.nih.gov. 2012-05-24. Retrieved 2012-09-08.
- Leyden, James J.; Kligman, Albert M. (1977), "Contact sensitization to benzoyl peroxide", Contact Dermatitis 3 (5): 273–75,
- Brodie, B. C. (1858), "Ueber die Bildung der Hyperoxyde organischer Säureradicale", Justus Liebigs Ann. Chem. 108: 79–83,
- Li, Hui, III (1998), Synthesis, Characterization and Properties of Vinyl Ester Matrix Resins (PDF), Ph.D. Dissertation, University of Vermont, Chapter 2
- Benzoyl peroxide (PDF), SIDS Initial Assessment Report, Geneva: United Nations Environment Programme, April 2004
- International Chemical Safety Card 0225
- "NIOSH Pocket Guide to Chemical Hazards #0052".
- SIDS Initial Assessment Report from the Organisation for Economic Co-operation and Development (OECD)
- "Benzoyl peroxide", Re-evaluation of Some Organic Chemicals, Hydrazine and Hydrogen Peroxide (PDF), IARC Monographs on the Evaluation of Carcinogenic Risks to Humans 71, Lyon, France: International Agency for Research on Cancer, 1999, pp. 345–58, .