Antiseptics phenol

As a disiafectant or antiseptic, phenol [108-95-2] (carboHc acid) is mosdy of historical iaterest. However, its extensive use continues ia both iavestigative and analytical microbiology, eg, as ia the AO AC phenol coefficient and use-dilution methods. 

Phenols occur widely throughout nature and also serve as intermediates in the industrial synthesis of products as diverse as adhesives and antiseptics. Phenol itself is a general disinfectant found in coal tar methyl salicylate is a flavoring agent found in oil of wintergreen and the urushiols are the allergenic constituents of poison oak and poison ivy. Note that the word phenol is the name both of the specific compound hydroxybenzene and of a class of compounds. 

What does that mean Malcolm asked. The antiseptic, phenolic odor of the hospital made him wrinkle his nose. 

Medicinal creosote is a mixture of phenols, chiefly guaiacol and creosol (4-melhyl-2-meth-oxyphenol), obtained by distillation of wood tar. B.p. 480-500 K. It is almost colourless with a characteristic odour and is a strong antiseptic, less toxic than phenol. 

Pure phenol is a colourless crystalline substance, having m.p. 43°, and b.p. 182° on exposure to air, it slowly sublimes, and on exposure to light, develops a pink colour. It has a characteristic odour, and a limited solubility in water. Phenol in dilute aqueous solution has strongly antiseptic properties, but the crystalline substance should not be allowed to come in contact with the skin, as it may cause severe blistering. 

Because of its acidity phenol was known as carbolic acid when Joseph Lister intro duced It as an antiseptic in 1865 to prevent postopera tive bacterial infections that were then a life threatening hazard in even minor surgi cal procedures... 

Although resorcinol [108-46-3], C H O, a dihydric phenol, is a comparatively weak bactericide, a nuclear-substituted alkyl derivative, -hexylresorcinol [136-77-6], has a phenol coefficient of 45, and has had considerable use as a topical antiseptic. 

In addition lo its use in making resins and adhesives, phenol is also the starting material for the synthesis of chlorinated phenols and the food preservatives BHT (butylated hvdroxytoiuene) and BHA (butylated bydroxyanisole). Penta-chlorophenol, a widely used wood preservative, is prepared by reaction of phenol with excess CI2- The herbicide 2,4-D (2,4-dichlorophenoxyacetjc acid) is prepared from 2,4-dichlorophenol, and the hospital antiseptic agent hexa-chlorophene is prepared from 2,4,5-trichlorophenol. 

Phenol, once known as carbolic acid, HC6H50, is a weak add. It was one of the first antiseptics used by lister. Its K, is 1.1 X 10-1C. A solution of phenol is prepared by dissolving 14.5 g of phenol in enough water to make 892 mL of solution. For this solution, calculate... 

Phenol was the first commercial antiseptic its introduction into hospitals in the 1870s led to a dramatic decrease in deaths from postoperative infections. Its use for this purpose has long since been abandoned because phenol burns exposed tissue, but many modern antiseptics are phenol derivatives. Toluene has largely replaced benzene as a solvent because it is much less toxic. Oxidation of toluene in the body gives benzoic acid, which is readily eliminated and has none of the toxic properties of the oxidation products of benzene. Indeed, benzoic acid or its sodium salt (Na+, C6H5COO ions) is widely used as a preservative in foods and beverages, including fruit juices and soft drinks. 

Phenol is a germicide and disinfectant, and was first used by Lister in 1867 as an antiseptic in medicine. More effective and less toxic antiseptics have since been discovered. 

Phenol no longer plays any significant role as an antibacterial agent. It is of historical interest, since it was introduced by Lister in 1867 as an antiseptic and has been used as a standard for comparison with other disinfectants, which are then given a phenol coefficient in tests such as the Rideal-Walker test. 

As is apparent from the above information, there is no ideal disinfectant, antiseptic or preservative. All chemical agents have their limitations either in terms of their antimicrobial activity, resistance to organic matter, stability, incompatibility, irritancy, toxicity or corrosivity. To overcome the limitations of an individual agent, formulations consisting of combinations of agents are available. For example, ethanol has been combined with chlorhexidine and iodine to produce more active preparations. The combination of chlorhexidine and cetrimide is also considered to improve activity. QACs and phenols have been combined with glutaraldehyde so that the same effect can be achieved with lower, less irritant concentrations of glutaraldehyde. Some... 

Solid disinfectants (disinfectant powders) usually consist of a disinfectant substance diluted by an inert powder. For example phenolic substances adsorbed onto kieselguhr form the basis of many disinfectant powders, while another widely used powder of respectable antiquity is hypochlorite powder. Disinfectant or antiseptic powders for use in medicine include substances such as acrifiavine, or antifungal compounds such as zinc undecenoate or salicylic acid mixed with talc. 

The literature on basic- and acid-catalyzed alkylation of phenol and of its derivatives is wide [1,2], since this class of reactions finds industrial application for the synthesis of several intermediates 2-methylphenol as a monomer for the synthesis of epoxy cresol novolac resin 2,5-dimethylphenol as an intermediate for the synthesis of antiseptics, dyes and antioxidants 2,6-dimethylphenol used for the manufacture of polyphenylenoxide resins, and 2,3,6-trimethylphenol as a starting material for the synthesis of vitamin E. The nature of the products obtained in phenol methylation is affected by the surface characteristics of the catalyst, since catalysts having acid features address the electrophilic substitution in the ortho and para positions with respect to the hydroxy group (steric effects in confined environments may however affect the ortho/para-C-alkylation ratio), while with basic catalysts the ortho positions become the... 

Carbolic acid is the old-fashioned name for hydroxybenzene (VII), otherwise known as phenol. It was first used as an antiseptic to prevent the infection of post-operative wounds. The British surgeon Joseph (later Lord ) Lister (1827-1912) discovered these antiseptic qualities in 1867 while working as Professor of Medicine at the Glasgow Royal Infirmary. He squirted a... 

The antibacterial properties of VII are no longer utilized in modem hospitals because more potent antiseptics have now been formulated. But its memory persists in the continued use of carbolic soap , which contains small amounts of phenol. 

---