Butylparaben

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Butylparaben
Butylparaben.svg
Identifiers
CAS number 94-26-8 YesY
PubChem 7184
ChemSpider 6916 YesY
UNII 3QPI1U3FV8 YesY
KEGG D01420 YesY
ChEMBL CHEMBL459008 YesY
Jmol-3D images Image 1
Properties
Molecular formula C11H14O3
Molar mass 194.23 g mol−1
Appearance Colorless, odorless, crystalline powder
Melting point 68 to 69 °C (154 to 156 °F; 341 to 342 K)
Solubility in water Slightly soluble
Solubility in acetone, ethanol, chloroform, glycerin, propylene glycol Soluble
Hazards
NFPA 704
Flammability code 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g., canola oil Health code 1: Exposure would cause irritation but only minor residual injury. E.g., turpentine Reactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g., liquid nitrogen Special hazards (white): no codeNFPA 704 four-colored diamond
Related compounds
Related compounds Paraben
Ethylparaben
Methylparaben
Propylparaben
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
 YesY (verify) (what is: YesY/N?)
Infobox references

Butylparaben, or butyl paraben, is a member of the paraben family, which has the formula C4H9(C6H4(OH)COO).[1] It is used as an antimicrobial preservative in cosmetics such as eye shadow, foundation, sunscreen, facial moisturizer and skin anti-aging treatment.[2] It is also used in medication suspensions, and as a flavoring additive in food.[3] Butylparaben and the paraben family have come to public attention recently, due to a study reporting low concentrations of parabens in breast tumors, around 20.6±4.2 ng/g tissue.[4][5] However, parabens have not been proven to cause breast cancer.[6] Estimates by the U.S. Food and Drug Administration and the Center for Food Safety and Applied Nutrition have found that the average person is exposed to about 37 ng of butylparaben per day.[7]

Properties[edit]

Butylparaben is a fine, colorless, odorless, crystalline solid at room temperature. The molecular formula of butylparaben undergoes hydrolysis to its corresponding carboxylic acid in basic solutions. The antimicrobial activity of parabens increases with increasing alkyl chain length (methylparaben < ethylparaben < propylparaben < butylparaben < heptylparaben) and this antimicrobial activity is retained across the pH range of 4 to 8.[8] Antimicrobial activity is usually enhanced by combining butylparaben with other biocides such as formaldehyde releasers, isothiazolinones, or phenoxyethanol.[9] It has been shown that butylparaben has the ability to cross body barriers, and enter the body through the lungs, GI tract, and skin epithelium.[10]

Occurrence[edit]

Butylparaben is used as a preservative in some foods, cosmetics and drugs to prevent decomposition. It is added to low-ionic strength solutions to retard microbial growth.[11] Butylparaben is a very popular preservative for use by manufacturing companies because of its unique ability to disrupt membrane transport properties. It is thought to do this by inhibiting DNA and RNA synthesis, and enzymes like ATPase and phosphotransferase in some bacterial species.[12] In 2003, butylparaben was cleared to be used as a flavor additive in food by the Food and Agriculture Organization and the World Health Organization.[13] Butylparaben can also be found in the sewage coming from bathroom pipes where people wash off makeup, and other skin care products. A study in 2001 found that concentrations of parabens in Danish sewage facilities could be up to 100 to 1000 times below the acute or chronic effect concentrations of butylparaben. An accurate risk assessment could not be made, however, based on the limited data available on the acute and chronic concentration levels of parabens.[14]

Preparation[edit]

Butylparaben is prepared by the esterification of 4-hydroxybenzoic acid with 1-butanol in the presence of an acid catalyst such as sulfuric acid.[15] It is available for commercial purchase from a number of different distributors, including Ashland Inc., J.T. Baker, and Penta Manufacturing Co.[16]

Uses and reactions[edit]

Butylparaben is one of the most commonplace bactericidal/fungicidal additives to cosmetics, probably due to its low cost, and efficiency as a microbial agent. It is reported by the EWG to be found in almost 3000 cosmetic products including eye shadow, facial moisturizer/treatment, anti-aging cream, foundation, and sunscreen.[17] In most cosmetics paraben is used at low levels, ranging from 0.01 to 0.3%.[18]

Numerous members of the paraben family are found in fruit and vegetable products, such as barley, flax seed, and grapes.[19] Butylparaben can also be found in low concentrations in liquid and solid medication suspensions, such as tylenol (acetaminophen) and ibuprofen.[20] In the paraben family, butylparaben appears to be the best antifungal agent. It is particularly active against molds and yeasts, and less active against bacteria.[21][22]

History[edit]

Butylparaben has been used in cosmetic products for over 80 years.[23] Its use in pharmaceutical products has occurred since 1924.[24] In December 2010 the Scientific Committee on Consumer Products (SCCP) of the European Union published that there is not enough data to perform risk assessments for butylparaben in humans.[25] Despite this publishing, Denmark banned butylparaben in products for use by children younger than the age of three, in March 2011.[26] Butylparaben is presently regulated by the U.S. Food and Drug Administration as a synthetic flavoring and adjuvant. It is recommended that it be used in the minimum amount necessary to achieve its intended effect.[27] Butylparaben is also regulated by the United States Environmental Protection Agency under the Toxic Substances Control Act of 1976 and the Federal Insecticide, Fungicide, and Rodenticide Act. Its pesticide registration was canceled in 1998.[28]

Safety and toxicology[edit]

Exposure to butylparaben can occur via inhalation, ingestion and eye or skin contact. Ingestion is not considered a safety concern because butylparaben is quickly absorbed, metabolized and excreted. Evidence of the absorbance of butylparaben through the skin, however, has shown that it can last much longer, and accumulate in epithelial tissue.[29] In mice, the Median lethal dose (LD50) is about 5000 mg/kg body weight.[30]

In replace of butylparaben, other preservative chemicals can be used such as phenoxyethanol and C12-15 alkyl benzoate.

Endocrine disruption[edit]

Butylparaben is estrogenic, meaning it mimics natural estrogen in the body.[31] For example, parabens can bind to estrogen receptors and regulate estrogen responsive gene products in experimental cell systems.[32] Long-chained parabens, like butylparaben, are more estrogenic than short-chained parabens, like methyl- or ethylparaben. This is likely because long-chained parabens are more lipophilic/hydrophobic, and have a higher affinity for estrogen receptors.[33]

Antiandrogenic[edit]

Butylparaben can decrease sperm function and alter metabolic hormones.[34] Rats exposed to a high concentration of butylparaben during pregnancy gave birth to fewer pups, and pups with malformed reproductive organs.[35] Mice administered butylparaben at 0.01-1% body weight for ten weeks showed a decrease in serum testosterone concentration and in spermatid counts in the seminiferous tubules.[36] A study on humans has found that reduced sperm counts and functional abnormalities in sperm are associated with elevated levels of butylparaben.[37] To date, no antiandrogen mechanisms have been found for any of these experimental systems.

Carcinogenicity[edit]

Butylparaben has been found in small concentrations in human breast fat and breast tumors.[38] A study by Darbre et al. (2004) has suggested that the underarm application of paraben-containing deodorants may attribute to breast cancer;[39] however, a review by the National Toxicology Program concluded, "There is no evidence of demonstrable risk for the development of breast cancer caused by the use of paraben-containing underarm cosmetics."[40] Animal studies have been inconclusive. Oral administration of butylparaben to eight-week-old rats has caused tumors such as thymic lymphoma, non-thymic lyphoid leukemia, and myeloid leukemia.[41] Similar studies, however, have found no significant increase in tumors upon butylparaben administration.[42] Butylparaben is not listed as a carcinogen by the International Agency for Research on Cancer.[43] The carcinogenicity of butylparaben is currently listed as "possible" by the Environmental Working Group.[44]

Ongoing/future research[edit]

Butylparaben is not considered to be a safety risk at this time for many governmental agencies around the world, but it is under close scrutiny, and the subject of ongoing research.[45][46][47] The Cosmetic Ingredient Review (CIR), an industry sponsored organization under the U.S. Food and Drug Administration that encourages researchers to submit their work, has reopened their safety assessment for parabens. The organization reviews and publishes credible research, and looks to answer the following questions: Is there a causal link between breast cancer and parabens? What are the concentrations of paraben that cause acute and chronic harm? Are there reproductive malformations caused by paraben exposure? [48] These questions and more are looking to be answered with the implementation of new research techniques and resources.

Notes[edit]

  1. ^ "Butylparaben Review of Toxicological Literature". National Toxicological Program. April 2005. 
  2. ^ "EWG's Skin Deep Cosmetics Database". Environmental Working Group. Retrieved 2011-10-25. 
  3. ^ "Parabens". U.S. Food and Drug Administration. Retrieved 2011-10-31. 
  4. ^ "Concentrations of Parabens in Human Breast Tumours". Journal of Applied Toxicology. 2004. 
  5. ^ "Butylparaben Review of Toxicological Literature". National Toxicological Program. April 2005. 
  6. ^ "Parabens". U.S. Food and Drug Administration. Retrieved 2011-10-31. 
  7. ^ "Butylparaben Review of Toxicological Literature". National Toxicological Program. April 2005. 
  8. ^ "Butylparaben". Med Scape. 2008. 
  9. ^ "Butylparaben". Med Scape. 2008. 
  10. ^ "Butylparaben Review of Toxicological Literature". National Toxicological Program. April 2005. 
  11. ^ "Butylparaben". Hazardous Substance Data Bank. 2004-2. 
  12. ^ "Hydrolysis of 4-Hydroxybenzoic Acid Esters (Parabens) and Their Aerobic Transformation into Phenol by the Resistant Enterobacter cloacae Strain EM". Applied and Environmental Microbiology. June 2001. 
  13. ^ "35th Session of the Codex Committee on Food Labeling". Biodiversity Policy and Practice. 2003. 
  14. ^ "The Royal Danish School of Pharmacology Annual Report 2001". The Royal Danish School of Pharmacology. 2001. 
  15. ^ "Butylparaben". Hazardous Substance Data Bank. 2004-2. 
  16. ^ "Butylparaben Review of Toxicological Literature". National Toxicological Program. April 2005. 
  17. ^ "EWG's Skin Deep Cosmetics Database". Environmental Working Group. Retrieved 2011-10-31. 
  18. ^ "Parabens". U.S. Food and Drug Administration. Retrieved 2011-10-31. 
  19. ^ "Parabens". Vashon Organics. Retrieved 2011-10-31. 
  20. ^ "Ibuprofen Suspension". FreshPatents.com. Retrieved 2011-10-31. 
  21. ^ "Butylparaben Review of Toxicological Literature". National Toxicological Program. April 2005. 
  22. ^ "Butylparaben". Hazardous Substance Data Bank. 2004-2. 
  23. ^ "Parabens as Preservatives". UENO FINE CHEMICALS INDUSTRY LTD. Retrieved 2011-10-31. 
  24. ^ "Parabens as Preservatives". UENO FINE CHEMICALS INDUSTRY LTD. Retrieved 2011-10-31. 
  25. ^ "Parabens used in personal care products and cosmetics". Chem Sec International. Retrieved 2011-10-31. 
  26. ^ "Parabens used in personal care products and cosmetics". Chem Sec International. Retrieved 2011-10-31. 
  27. ^ "Butylparaben Review of Toxicological Literature". National Toxicological Program. April 2005. 
  28. ^ "Butylparaben Review of Toxicological Literature". National Toxicological Program. April 2005. 
  29. ^ "Deodorants, Antiperspirants, Parabens & Breast Cancer". Control Your Impact. Retrieved 2011-10-31. 
  30. ^ "Butylparaben Review of Toxicological Literature". National Toxicological Program. April 2005. 
  31. ^ "The Royal Danish School of Pharmacology Annual Report 2001". The Royal Danish School of Pharmacology. 2001. 
  32. ^ "Butylparaben Review of Toxicological Literature". National Toxicological Program. April 2005. 
  33. ^ "Parabens used in personal care products and cosmetics". Chem Sec International. Retrieved 2011-10-31. 
  34. ^ "Parabens used in personal care products and cosmetics". Chem Sec International. Retrieved 2011-10-31. 
  35. ^ "Butylparaben Review of Toxicological Literature". National Toxicological Program. April 2005. 
  36. ^ "Butylparaben Review of Toxicological Literature". National Toxicological Program. April 2005. 
  37. ^ "Chemicals in cosmetics, moisturizers linked to DNA damage in human sperm". Environmental Health News. Retrieved 2011-10-31. 
  38. ^ "Butylparaben Review of Toxicological Literature". National Toxicological Program. April 2005. 
  39. ^ "Deodorants, Antiperspirants, Parabens & Breast Cancer". Controlyourimpact.com. Retrieved 2011-10-31. 
  40. ^ Butylparaben [CAS No. 94-26-8]: Review of Toxicological Literature. National Toxicology Program, National Institutes of Health. April 2005. 
  41. ^ "Butylparaben Review of Toxicological Literature". National Toxicological Program. April 2005. 
  42. ^ "Butylparaben Review of Toxicological Literature". National Toxicological Program. April 2005. 
  43. ^ Agents Classified by the IARC Monographs, Volumes 1–109. International Agency for Research on Cancer. 
  44. ^ "Human Toxone Project: Butylparaben". Environmental Working Group. Retrieved 2011-10-31. 
  45. ^ "Parabens". U.S. Food and Drug Administration. Retrieved 2011-10-31. 
  46. ^ "Endocrine disruptors". European Commission Environment. Retrieved 2011-10-31. 
  47. ^ "Butylparaben". Environmental Working Group. Retrieved 2011-10-31. 
  48. ^ "Parabens". U.S. Food and Drug Administration. Retrieved 2011-10-31.