Performic acid
Encyclopedia
Performic acid is an organic compound
with the formula
CH2O3. It is an unstable colorless liquid which can be produced by mixing formic acid
with hydrogen peroxide
. Owing to its oxidizing and disinfecting action, it is used in the chemical, medical and food industries.
, benzene
, chloroform
and other organic solvents. Its strong oxidizing properties are used for cleaving disulfide bond
s in protein mapping, as well as for epoxidation, hydroxylation and oxidation reactions in organic synthesis. In the medical and food industries, performic acid is commonly used to disinfect equipment. It is effective against viruses, bacterial spores, algae
, microscopic fungi and mycobacteria
, as well as other microorganism
s as zooplankton
. The popularity of performic acid as a sterilizer originates from the safe nature of its degradation products, mostly carbon dioxide
, oxygen and water. The disinfecting action of performic acid is also faster than that of the related compounds peracetic acid and hydrogen peroxide. The major drawbacks of performic acid are handling dangers related to its high reactivity, as well as instability, especially upon heating, which means that the acid must be used within about 12 hours of it being synthesised.
This reaction is reversible and can be used for large scale industrial production if accelerated with a catalyst; however, its temperature must be kept below 80–85 °C to avoid an explosion. The catalyst can be nitric
, hydrofluoric
, phosphoric
or sulfuric acid
or their salts; it can also be an organic compound containing at least one ester
group, such as carboxylic acid
ester
or peracetic acid.
, benzaldehyde
, or aniline
, and explodes violently upon addition of metal powders. For this reason, spilled performic acid is diluted with cold water and collected with neutral, non-flammable inorganic absorbents, such as vermiculite
.
Organic compound
An organic compound is any member of a large class of gaseous, liquid, or solid chemical compounds whose molecules contain carbon. For historical reasons discussed below, a few types of carbon-containing compounds such as carbides, carbonates, simple oxides of carbon, and cyanides, as well as the...
with the formula
Chemical formula
A chemical formula or molecular formula is a way of expressing information about the atoms that constitute a particular chemical compound....
CH2O3. It is an unstable colorless liquid which can be produced by mixing formic acid
Formic acid
Formic acid is the simplest carboxylic acid. Its chemical formula is HCOOH or HCO2H. It is an important intermediate in chemical synthesis and occurs naturally, most notably in the venom of bee and ant stings. In fact, its name comes from the Latin word for ant, formica, referring to its early...
with hydrogen peroxide
Hydrogen peroxide
Hydrogen peroxide is the simplest peroxide and an oxidizer. Hydrogen peroxide is a clear liquid, slightly more viscous than water. In dilute solution, it appears colorless. With its oxidizing properties, hydrogen peroxide is often used as a bleach or cleaning agent...
. Owing to its oxidizing and disinfecting action, it is used in the chemical, medical and food industries.
Properties and applications
Performic acid is a colorless liquid soluble in water, alcohols, etherEther
Ethers are a class of organic compounds that contain an ether group — an oxygen atom connected to two alkyl or aryl groups — of general formula R–O–R'. A typical example is the solvent and anesthetic diethyl ether, commonly referred to simply as "ether"...
, benzene
Benzene
Benzene is an organic chemical compound. It is composed of 6 carbon atoms in a ring, with 1 hydrogen atom attached to each carbon atom, with the molecular formula C6H6....
, chloroform
Chloroform
Chloroform is an organic compound with formula CHCl3. It is one of the four chloromethanes. The colorless, sweet-smelling, dense liquid is a trihalomethane, and is considered somewhat hazardous...
and other organic solvents. Its strong oxidizing properties are used for cleaving disulfide bond
Disulfide bond
In chemistry, a disulfide bond is a covalent bond, usually derived by the coupling of two thiol groups. The linkage is also called an SS-bond or disulfide bridge. The overall connectivity is therefore R-S-S-R. The terminology is widely used in biochemistry...
s in protein mapping, as well as for epoxidation, hydroxylation and oxidation reactions in organic synthesis. In the medical and food industries, performic acid is commonly used to disinfect equipment. It is effective against viruses, bacterial spores, algae
Algae
Algae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms, such as the giant kelps that grow to 65 meters in length. They are photosynthetic like plants, and "simple" because their tissues are not organized into the many...
, microscopic fungi and mycobacteria
Mycobacterium
Mycobacterium is a genus of Actinobacteria, given its own family, the Mycobacteriaceae. The genus includes pathogens known to cause serious diseases in mammals, including tuberculosis and leprosy...
, as well as other microorganism
Microorganism
A microorganism or microbe is a microscopic organism that comprises either a single cell , cell clusters, or no cell at all...
s as zooplankton
Zooplankton
Zooplankton are heterotrophic plankton. Plankton are organisms drifting in oceans, seas, and bodies of fresh water. The word "zooplankton" is derived from the Greek zoon , meaning "animal", and , meaning "wanderer" or "drifter"...
. The popularity of performic acid as a sterilizer originates from the safe nature of its degradation products, mostly carbon dioxide
Carbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
, oxygen and water. The disinfecting action of performic acid is also faster than that of the related compounds peracetic acid and hydrogen peroxide. The major drawbacks of performic acid are handling dangers related to its high reactivity, as well as instability, especially upon heating, which means that the acid must be used within about 12 hours of it being synthesised.
Synthesis
Synthesis of pure performic acid has not been reported. Aqueous solutions (up to 90%) can be prepared by mixing 70–98 wt.% of formic acid (in water) with 35–50 wt% of hydrogen peroxide.This reaction is reversible and can be used for large scale industrial production if accelerated with a catalyst; however, its temperature must be kept below 80–85 °C to avoid an explosion. The catalyst can be nitric
Nitric acid
Nitric acid , also known as aqua fortis and spirit of nitre, is a highly corrosive and toxic strong acid.Colorless when pure, older samples tend to acquire a yellow cast due to the accumulation of oxides of nitrogen. If the solution contains more than 86% nitric acid, it is referred to as fuming...
, hydrofluoric
Hydrofluoric acid
Hydrofluoric acid is a solution of hydrogen fluoride in water. It is a valued source of fluorine and is the precursor to numerous pharmaceuticals such as fluoxetine and diverse materials such as PTFE ....
, phosphoric
Phosphoric acid
Phosphoric acid, also known as orthophosphoric acid or phosphoric acid, is a mineral acid having the chemical formula H3PO4. Orthophosphoric acid molecules can combine with themselves to form a variety of compounds which are also referred to as phosphoric acids, but in a more general way...
or sulfuric acid
Sulfuric acid
Sulfuric acid is a strong mineral acid with the molecular formula . Its historical name is oil of vitriol. Pure sulfuric acid is a highly corrosive, colorless, viscous liquid. The salts of sulfuric acid are called sulfates...
or their salts; it can also be an organic compound containing at least one ester
Ester
Esters are chemical compounds derived by reacting an oxoacid with a hydroxyl compound such as an alcohol or phenol. Esters are usually derived from an inorganic acid or organic acid in which at least one -OH group is replaced by an -O-alkyl group, and most commonly from carboxylic acids and...
group, such as carboxylic acid
Carboxylic acid
Carboxylic acids are organic acids characterized by the presence of at least one carboxyl group. The general formula of a carboxylic acid is R-COOH, where R is some monovalent functional group...
ester
Ester
Esters are chemical compounds derived by reacting an oxoacid with a hydroxyl compound such as an alcohol or phenol. Esters are usually derived from an inorganic acid or organic acid in which at least one -OH group is replaced by an -O-alkyl group, and most commonly from carboxylic acids and...
or peracetic acid.
Safety
Performic acid is non-toxic; it does irritate the skin, but less so than peracetic acid. Concentrated acid (above 50%) is highly reactive; it readily decomposes upon heating, and explodes upon rapid heating to 80–85 °C. It may ignite or explode at room temperature when combined with flammable substances, such as formaldehydeFormaldehyde
Formaldehyde is an organic compound with the formula CH2O. It is the simplest aldehyde, hence its systematic name methanal.Formaldehyde is a colorless gas with a characteristic pungent odor. It is an important precursor to many other chemical compounds, especially for polymers...
, benzaldehyde
Benzaldehyde
Benzaldehyde is an organic compound consisting of a benzene ring with a formyl substituent. It is the simplest aromatic aldehyde and one of the most industrially useful. This colorless liquid has a characteristic pleasant almond-like odor...
, or aniline
Aniline
Aniline, phenylamine or aminobenzene is an organic compound with the formula C6H5NH2. Consisting of a phenyl group attached to an amino group, aniline is the prototypical aromatic amine. Being a precursor to many industrial chemicals, its main use is in the manufacture of precursors to polyurethane...
, and explodes violently upon addition of metal powders. For this reason, spilled performic acid is diluted with cold water and collected with neutral, non-flammable inorganic absorbents, such as vermiculite
Vermiculite
Vermiculite is a natural mineral that expands with the application of heat. The expansion process is called exfoliation and it is routinely accomplished in purpose-designed commercial furnaces. Vermiculite is formed by weathering or hydrothermal alteration of biotite or phlogopite...
.