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

organic compound Some chemical authorities define an organic compound as a chemical compound that contains a carbon–hydrogen or carbon–carbon bond; others consider an organic compound to be any chemical compound that contains carbon. For example, carbon-co ...

with the

formula In science, a formula is a concise way of expressing information symbolically, as in a mathematical formula or a ''chemical formula''. The informal use of the term ''formula'' in science refers to the general construct of a relationship betwe ...

CH₃CO₃H. This peroxy acid is a colorless liquid with a characteristic acrid odor reminiscent of

acetic acid Acetic acid , systematically named ethanoic acid , is an acidic, colourless liquid and organic compound with the chemical formula (also written as , , or ). Vinegar is at least 4% acetic acid by volume, making acetic acid the main compone ...

. It can be highly

corrosive Corrosion is a natural process that converts a refined metal into a more chemically stable oxide. It is the gradual deterioration of materials (usually a metal) by chemical or electrochemical reaction with their environment. Corrosion engine ...

. 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 Acetaldehyde (IUPAC systematic name ethanal) is an organic compound, organic chemical compound with the chemical formula, formula , sometimes abbreviated as . It is a colorless liquid or gas, boiling near room temperature. It is one of the most ...

: :O₂ + CH₃CHO → CH₃CO₃H Peracetic acid is conventionally prepared by combining

and

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 viscosity, viscous than Properties of water, water. It is used as an oxidizer, bleaching agent, and antiseptic, usua ...

with homogeneous acid catalysts (e.g., sulfuric acid), which facilitate the reaction and achieve equilibrium between the reagents and product: :H₂O₂ + CH₃CO₂H CH₃CO₃H + H₂O While it is feasible to create peracetic acid by combining consumer-grade vinegar (5%

) and

(3%) without an acid catalyst, the low concentration of reagents will result in a slow reaction rate at room temperature. Extrapolating from published reaction rates, the time to equilibrium is estimated to be on the order of weeks. As an alternative, acetyl chloride and

acetic anhydride Acetic anhydride, or ethanoic anhydride, is the chemical compound with the chemical formula, formula . Commonly abbreviated , it is one the simplest organic acid anhydride, anhydrides of a carboxylic acid and is widely used in the production of c ...

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

in situ is a Latin phrase meaning 'in place' or 'on site', derived from ' ('in') and ' ( ablative of ''situs'', ). The term typically refers to the examination or occurrence of a process within its original context, without relocation. The term is use ...

'' 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 of ...

s. This is achieved by the action of bleach activators, such as tetraacetylethylenediamine and sodium nonanoyloxybenzenesulfonate, upon hydrogen peroxide formed from sodium percarbonate in water. The peracetic acid is a more effective bleaching agent than hydrogen peroxide itself. PAA is also formed naturally in the environment through a series of photochemical reactions involving

formaldehyde Formaldehyde ( , ) (systematic name methanal) is an organic compound with the chemical formula and structure , more precisely . The compound is a pungent, colourless gas that polymerises spontaneously into paraformaldehyde. It is stored as ...

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 agency of the United States government tasked with environmental protection matters. President Richard Nixon proposed the establishment of EPA on July 9, 1970; it began operation on De ...

first registered peracetic acid as an

antimicrobial An antimicrobial is an agent that kills microorganisms (microbicide) or stops their growth (bacteriostatic agent). Antimicrobial medicines can be grouped according to the microorganisms they are used to treat. For example, antibiotics are used aga ...

in 1986 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 heat and cool the ...

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

Legionella ''Legionella'' is a genus of gram-negative bacteria, gram-negative bacteria that can be seen using a silver stain or grown in a special media that contains cysteine, an amino acid. It is known to cause legionellosis (all illnesses caused by ''Legi ...

'' bacteria. Nu-Cidex is the

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 fictitious business name. Registering the fictitious name with ...

for a brand of antimicrobial peracetic acid. 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 is a highly potent synthetic piperidine opioid primarily used as an analgesic (pain medication). It is 30 to 50 times more Potency (pharmacology), potent than heroin and 50 to 100 times more potent than morphine. Its primary Medici ...

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 of various

alkene In organic chemistry, an alkene, or olefin, is a hydrocarbon containing a carbon–carbon double bond. The double bond may be internal or at the terminal position. Terminal alkenes are also known as Alpha-olefin, α-olefins. The Internationa ...

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 applications 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).

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 ''electron donor''). In ot ...

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