Peracetic acid (also known as peroxyacetic acid, or PAA) is an

organic compound In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. T ...

with the formula CH₃CO₃H. This peroxy acid is a colorless liquid with a characteristic acrid odor reminiscent of acetic acid. It can be highly

corrosive A corrosive substance is one that will damage or destroy other substances with which it comes into contact by means of a chemical reaction. Etymology The word ''corrosive'' is derived from the Latin verb ''corrodere'', which means ''to gnaw'', ...

. Peracetic acid is a weaker acid than the parent acetic acid, with a p''K''_a of 8.2.

Production

Peracetic acid is produced industrially by the autoxidation of acetaldehyde: :O₂ + CH₃CHO → CH₃CO₃H It forms upon treatment of acetic acid with

hydrogen peroxide Hydrogen peroxide is a chemical compound with the formula . In its pure form, it is a very pale blue liquid that is slightly more viscous than water. It is used as an oxidizer, bleaching agent, and antiseptic, usually as a dilute solution (3%� ...

with a strong acid catalyst: :H₂O₂ + CH₃CO₂H CH₃CO₃H + H₂O As an alternative,

acetyl chloride Acetyl chloride (CH3COCl) is an acyl chloride derived from acetic acid. It belongs to the class of organic compounds called acid halides. It is a colorless, corrosive, volatile liquid. Its formula is commonly abbreviated to AcCl. Synthesis On a ...

and acetic anhydride can be used to generate a solution of the acid with lower water content. Peracetic acid is generated ''

in situ ''In situ'' (; often not italicized in English) is a Latin phrase that translates literally to "on site" or "in position." It can mean "locally", "on site", "on the premises", or "in place" to describe where an event takes place and is used in ...

'' by some

laundry detergent Laundry detergent is a type of detergent (cleaning agent) used for cleaning dirty laundry (clothes). Laundry detergent is manufactured in powder (washing powder) and liquid form. While powdered and liquid detergents hold roughly equal share o ...

s. This is achieved by the action of bleach activators, such as

tetraacetylethylenediamine Tetraacetylethylenediamine, commonly abbreviated as TAED, is an organic compound with the formula (CH3C(O))2NCH2CH2N(C(O)CH3)2. This white solid is commonly used as a bleach activator in laundry detergents and for paper pulp. It is produced by ac ...

and sodium nonanoyloxybenzenesulfonate, upon hydrogen peroxide formed from

sodium percarbonate Sodium percarbonate is a chemical substance with formula . It is an adduct of sodium carbonate ("soda ash" or "washing soda") and hydrogen peroxide (that is, a perhydrate) whose formula is more properly written as 2 · 3 . ...

in water. The peracetic acid is a more effective

bleaching agent Bleach is the generic name for any chemical product that is used industrially or domestically to remove color (whitening) from a fabric or fiber or to clean or to remove stains in a process called bleaching. It often refers specifically, to ...

than hydrogen peroxide itself. PAA is also formed naturally in the environment through a series of

photochemical reaction Organic photochemistry encompasses organic reactions that are induced by the action of light. The absorption of ultraviolet light by organic molecules often leads to reactions. In the earliest days, sunlight was employed, while in more modern times ...

s involving

formaldehyde Formaldehyde ( , ) (systematic name methanal) is a naturally occurring organic compound with the formula and structure . The pure compound is a pungent, colourless gas that polymerises spontaneously into paraformaldehyde (refer to section ...

and photo-oxidant radicals. Peracetic acid is always sold in solution as a mixture with acetic acid and hydrogen peroxide to maintain its stability. The concentration of the acid as the active ingredient can vary.

Uses

The

United States Environmental Protection Agency The Environmental Protection Agency (EPA) is an independent executive agency of the United States federal government tasked with environmental protection matters. President Richard Nixon proposed the establishment of EPA on July 9, 1970; it ...

first registered peracetic acid as an

antimicrobial An antimicrobial is an agent that kills microorganisms or stops their growth. Antimicrobial medicines can be grouped according to the microorganisms they act primarily against. For example, antibiotics are used against bacteria, and antifungals ar ...

in 1985 for indoor use on hard surfaces. Use sites include agricultural premises, food establishments, medical facilities, and home bathrooms. Peracetic acid is also registered for use in dairy and cheese processing plants, on food processing equipment, and in pasteurizers in breweries, wineries, and beverage plants. It is also applied for the disinfection of medical supplies, to prevent biofilm formation in pulp industries, and as a water purifier and disinfectant. Peracetic acid can be used as a

cooling tower A cooling tower is a device that rejects waste heat to the atmosphere through the cooling of a coolant stream, usually a water stream to a lower temperature. Cooling towers may either use the evaporation of water to remove process heat an ...

water disinfectant, where it prevents biofilm formation and effectively controls ''

Legionella ''Legionella'' is a genus of pathogenic gram-negative bacteria that includes the species '' L. pneumophila'', causing legionellosis (all illnesses caused by ''Legionella'') including a pneumonia-type illness called Legionnaires' disease and a mil ...

'' bacteria. A

trade name A trade name, trading name, or business name, is a pseudonym used by companies that do not operate under their registered company name. The term for this type of alternative name is a "fictitious" business name. Registering the fictitious name w ...

for peracetic acid as an antimicrobial is Nu-Cidex. In the European Union, peroxyacetic acid was reported by the EFSA after submission in 2013 by the US Department of Agriculture . Decontamination kits for cleaning

fentanyl Fentanyl, also spelled fentanil, is a very potent synthetic opioid used as a pain medication. Together with other drugs, fentanyl is used for anesthesia. It is also used illicitly as a recreational drug, sometimes mixed with heroin, cocain ...

analogues from surfaces (as used by many police forces, amongst others) often contain solid peracetyl borate, which mixes with water to produce peracetic acid.

Epoxidation

Although less active than more acidic peracids (e.g., ''m''-CPBA), peracetic acid in various forms is used for the

epoxidation In organic chemistry, an epoxide is a cyclic ether () with a three-atom ring. This ring approximates an equilateral triangle, which makes it strained, and hence highly reactive, more so than other ethers. They are produced on a large scale ...

of various

alkene In organic chemistry, an alkene is a hydrocarbon containing a carbon–carbon double bond. Alkene is often used as synonym of olefin, that is, any hydrocarbon containing one or more double bonds.H. Stephen Stoker (2015): General, Organic, an ...

s (

Prilezhaev reaction The Prilezhaev reaction, also known as the Prileschajew reaction or Prilezhaev epoxidation, is the chemical reaction of an alkene with a peroxy acid to form epoxides. It is named after Nikolai Prilezhaev, who first reported this reaction in 1909 ...

). Useful application are for unsaturated fats, synthetic and natural rubbers, and some natural products such as

pinene Pinene is a collection of unsaturated bicyclic monoterpenes. Two geometric isomers of pinene are found in nature, α-pinene and β-pinene. Both are chiral. As the name suggests, pinenes are found in pines. Specifically, pinene is the major comp ...

. A variety of factors affect the amount of free acid or sulfuric acid (used to prepare the peracid in the first place).

Safety

Peracetic acid is a strong

oxidizing agent An oxidizing agent (also known as an oxidant, oxidizer, electron recipient, or electron acceptor) is a substance in a redox chemical reaction that gains or " accepts"/"receives" an electron from a (called the , , or ). In other words, an oxi ...

and severe irritant to the skin, eyes, and respiratory system. The U.S. Environmental Protection Agency published the following Acute Exposure Guideline Levels (AEGL):

References

{{Authority control Bleaches Disinfectants Organic peroxy acids Foul-smelling chemicals

Production

Uses

Epoxidation

Safety

See also

References