Rubbing alcohol is either an

isopropyl alcohol Isopropyl alcohol (IUPAC name propan-2-ol and also called isopropanol or 2-propanol) is a colorless, flammable organic compound with a pungent alcoholic odor. As an isopropyl group linked to a hydroxyl group (chemical formula ) it is the simp ...

or an

ethanol Ethanol (abbr. EtOH; also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound. It is an alcohol with the chemical formula . Its formula can be also written as or (an ethyl group linked to a h ...

-based liquid, with isopropyl alcohol products being the most widely available. The comparable ''

British Pharmacopoeia The ''British Pharmacopoeia'' (''BP'') is the national pharmacopoeia of the United Kingdom. It is an annually published collection of quality standards for medicinal substances in the UK, which is used by individuals and organisations invo ...

'' (''BP'') is surgical spirit. Rubbing alcohol is denatured and undrinkable even if it is ethanol-based, due to the bitterants added. They are liquids used primarily as a

topical A topical medication is a medication that is applied to a particular place on or in the body. Most often topical medication means application to body surfaces such as the skin or mucous membranes to treat ailments via a large range of class ...

antiseptic An antiseptic (from Greek ἀντί ''anti'', "against" and σηπτικός ''sēptikos'', "putrefactive") is an antimicrobial substance or compound that is applied to living tissue/skin to reduce the possibility of infection, sepsis, or putre ...

. They also have multiple industrial and household applications. The term "rubbing alcohol" in North American English is a general term for either isopropyl alcohol (isopropanol) or ethyl alcohol (ethanol) products. The ''

United States Pharmacopeia The ''United States Pharmacopeia'' (''USP'') is a pharmacopeia (compendium of drug information) for the United States published annually by the United States Pharmacopeial Convention (usually also called the USP), a nonprofit organization tha ...

'' (''USP'') defines "isopropyl rubbing alcohol USP" as containing approximately 70 percent

alcohol by volume Alcohol by volume (abbreviated as ABV, abv, or alc/vol) is a standard measure of how much alcohol (ethanol) is contained in a given volume of an alcoholic beverage (expressed as a volume percent). It is defined as the number of millilitres (mL) o ...

of pure isopropyl alcohol and defines "rubbing alcohol USP" as containing approximately 70 percent by volume of denatured alcohol. In Ireland and the UK, the comparable preparation is surgical spirit B.P., which the ''British Pharmacopoeia'' defines as 95% methylated spirit, 2.5%

castor oil Castor oil is a vegetable oil pressed from castor beans. It is a colourless or pale yellow liquid with a distinct taste and odor. Its boiling point is and its density is 0.961 g/cm3. It includes a mixture of triglycerides in which abo ...

, 2% diethyl phthalate, and 0.5% methyl salicylate. Under its alternative name of "wintergreen oil", methyl salicylate is a common additive to North American rubbing alcohol products. Individual manufacturers are permitted to use their own formulation standards in which the ethanol content for retail bottles of rubbing alcohol is labeled as and ranges from 70 to 99% v/v. All rubbing alcohols are unsafe for human consumption: isopropyl rubbing alcohols do not contain the ethyl alcohol of alcoholic beverages; ethyl rubbing alcohols are based on denatured alcohol, which is a combination of ethyl alcohol and one or more bitter poisons that make the substance toxic.

History

The term "rubbing alcohol" came into prominence in North America in the mid-1920s. The ''original'' rubbing alcohol was literally used as a

liniment Liniment (from la, linere, meaning "to anoint"), also called embrocation and heat rub, is a medicated topical preparation for application to the skin. Some liniments have viscosity similar to that of water; others are lotion or balm; still othe ...

for

massage Massage is the manipulation of the body's soft tissues. Massage techniques are commonly applied with hands, fingers, elbows, knees, forearms, feet or a device. The purpose of massage is generally for the treatment of body stress or pain. In E ...

; hence the name. This original rubbing alcohol was rather different from today's precisely formulated surgical spirit; in some formulations it was perfumed and included different additives, notably a higher concentration of methyl salicylate. The name "rubbing" also emphasized that the alcohol was not intended for consumption, a significant distinction in Prohibition-era America; nonetheless it had become a well-documented surrogate alcohol as early as 1925.

Properties

All rubbing alcohols are volatile and

flammable A combustible material is something that can burn (i.e., ''combust'') in air. A combustible material is flammable if it ignites easily at ambient temperatures. In other words, a combustible material ignites with some effort and a flammable mat ...

. Ethyl rubbing alcohol has an extremely bitter taste from additives. The

specific gravity Relative density, or specific gravity, is the ratio of the density (mass of a unit volume) of a substance to the density of a given reference material. Specific gravity for liquids is nearly always measured with respect to water (molecule), wa ...

of Formula 23-H is between 0.8691 and 0.8771 at . Isopropyl rubbing alcohols contain from 50% to 99% by volume of isopropyl alcohol, the remainder consisting of water. Boiling points vary with the proportion of isopropyl alcohol from ; likewise, freezing points vary from . Surgical spirit BP boils at . Naturally colorless, products may contain color additives. They may also contain medically-inactive additives for fragrance, such as wintergreen oil (methyl salicylate), or for other purposes.

US legislation

To protect alcohol tax revenue in the United States all preparations classified as ''Rubbing Alcohols'' (defined as those containing ethanol) must have poisonous additives to limit human consumption in accordance with the requirements of the US Treasury Department, Bureau of Alcohol, Tobacco, and Firearms, using Formula 23-H (8 parts by volume of

acetone Acetone (2-propanone or dimethyl ketone), is an organic compound with the formula . It is the simplest and smallest ketone (). It is a colorless, highly volatile and flammable liquid with a characteristic pungent odour. Acetone is miscible wi ...

, 1.5 parts by volume of methyl isobutyl ketone, and 100 parts by volume of ethyl alcohol). It contains 87.5–91% by volume of absolute ethyl alcohol. The rest consists of water and the denaturants, with or without color additives, and perfume oils. Rubbing alcohol contains in each 100 ml more than 355 mg of sucrose octaacetate or more than 1.40 mg of denatonium benzoate. The preparation may be colored with one or more color additives. A suitable stabilizer may also be added.Expert Committee:(PA2)Pharmaceutical Analysis 2, USP28–NF23 Page 62, Pharmacopeial Forum:Volume No.27(3)Page 250

/ref>

Warnings

Product labels for rubbing alcohol include a number of warnings about the chemical, including the flammability hazards and its intended use only as a topical antiseptic and not for internal wounds or consumption. It should be used in a well-ventilated area due to inhalation hazards. Poisoning can occur from ingestion, inhalation, Absorption (chemistry), absorption, or consumption of rubbing alcohol.

References

External links

Why Is Drinking Rubbing Alcohol Bad?
{{DEFAULTSORT:Rubbing Alcohol Antiseptics Cleaning products Household chemicals