Sodium benzoate also known as benzoate of soda is the

sodium Sodium is a chemical element; it has Symbol (chemistry), symbol Na (from Neo-Latin ) and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 element, group 1 of the peri ...

salt In common usage, salt is a mineral composed primarily of sodium chloride (NaCl). When used in food, especially in granulated form, it is more formally called table salt. In the form of a natural crystalline mineral, salt is also known as r ...

benzoic acid Benzoic acid () is a white (or colorless) solid organic compound with the formula , whose structure consists of a benzene ring () with a carboxyl () substituent. The benzoyl group is often abbreviated "Bz" (not to be confused with "Bn," which ...

, widely used as a food preservative (with an

E number E numbers, short for Europe numbers, are codes for substances used as food additives, including those found naturally in many foods, such as vitamin C, for use within the European Union (EU) and European Free Trade Association (EFTA). Commonly ...

of E211) and a pickling agent. It appears as a white crystalline chemical 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 ...

C₆H₅COONa.

Production

Sodium benzoate is commonly produced by the neutralization of

sodium hydroxide Sodium hydroxide, also known as lye and caustic soda, is an inorganic compound with the formula . It is a white solid ionic compound consisting of sodium cations and hydroxide anions . Sodium hydroxide is a highly corrosive base (chemistry), ...

(NaOH) with

(C₆H₅COOH), which is itself produced commercially by

partial oxidation Partial oxidation (POX) is a type of chemical reaction. It occurs when a substoichiometric fuel-air mixture is partially combusted in a reformer, creating a hydrogen-rich syngas which can then be put to further use, for example in a fuel cell. A d ...

toluene Toluene (), also known as toluol (), is a substituted aromatic hydrocarbon with the chemical formula , often abbreviated as , where Ph stands for the phenyl group. It is a colorless, water Water is an inorganic compound with the c ...

with

oxygen Oxygen is a chemical element; it has chemical symbol, symbol O and atomic number 8. It is a member of the chalcogen group (periodic table), group in the periodic table, a highly reactivity (chemistry), reactive nonmetal (chemistry), non ...

Reactions

Sodium benzoate can be decarboxylated with strong base and heat, yielding

benzene Benzene is an Organic compound, organic chemical compound with the Chemical formula#Molecular formula, molecular formula C6H6. The benzene molecule is composed of six carbon atoms joined in a planar hexagonal Ring (chemistry), ring with one hyd ...

: :

Natural occurrence

Sodium benzoate is not a naturally occurring substance. However many foods are natural sources of benzoic acid, its salts, and its

ester In chemistry, an ester is a compound derived from an acid (either organic or inorganic) in which the hydrogen atom (H) of at least one acidic hydroxyl group () of that acid is replaced by an organyl group (R). These compounds contain a distin ...

Fruit In botany, a fruit is the seed-bearing structure in flowering plants (angiosperms) that is formed from the ovary after flowering. Fruits are the means by which angiosperms disseminate their seeds. Edible fruits in particular have long propaga ...

s and

vegetable Vegetables are edible parts of plants that are consumed by humans or other animals as food. This original meaning is still commonly used, and is applied to plants collectively to refer to all edible plant matter, including edible flower, flo ...

s can be rich sources, particularly berries such as

cranberry Cranberries are a group of evergreen dwarf shrubs or trailing vines in the subgenus ''Oxycoccus'' of the genus ''Vaccinium''. Cranberries are low, creeping shrubs or vines up to long and in height; they have slender stems that are not th ...

and

bilberry Bilberries () are Eurasian low-growing shrubs in the genus ''Vaccinium'' in the flowering plant family Ericaceae that bear edible, dark blue berries. They resemble but are distinct from North American blueberries. The species most often referre ...

. Other sources include

seafood Seafood is any form of Marine life, sea life regarded as food by humans, prominently including Fish as food, fish and shellfish. Shellfish include various species of Mollusca, molluscs (e.g., bivalve molluscs such as clams, oysters, and mussel ...

, such as

prawn Prawn is a common name for small aquatic crustaceans with an exoskeleton An exoskeleton () . is a skeleton that is on the exterior of an animal in the form of hardened integument, which both supports the body's shape and protects the intern ...

s, and

dairy product Dairy products or milk products are food products made from (or containing) milk. The most common dairy animals are cow, water buffalo, goat, nanny goat, and Sheep, ewe. Dairy products include common grocery store food around the world such as y ...

Uses

As a preservative

Sodium benzoate can act as a food preservative. It is most widely used in acidic foods such as

salad dressing A salad dressing is a sauce for salads, used on virtually all leafy salads. Dressings may also be used in preparing salads of beans (e.g., three bean salad), noodle or pasta salads and antipasti, and forms of potato salad. A dressing may even ...

s (for example

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 ...

vinegar Vinegar () is an aqueous solution of diluted acetic acid and trace compounds that may include flavorings. Vinegar typically contains from 5% to 18% acetic acid by volume. Usually, the acetic acid is produced by a double fermentation, converting ...

), carbonated drinks (

carbonic acid Carbonic acid is a chemical compound with the chemical formula . The molecule rapidly converts to water and carbon dioxide in the presence of water. However, in the absence of water, it is quite stable at room temperature. The interconversion ...

), jams and

fruit juices Juice is a drink made from the extraction or pressing of the natural liquid contained in fruit and vegetables. It can also refer to liquids that are flavored with concentrate or other biological food sources, such as meat or seafood, such a ...

(

citric acid Citric acid is an organic compound with the formula . It is a Transparency and translucency, colorless Weak acid, weak organic acid. It occurs naturally in Citrus, citrus fruits. In biochemistry, it is an intermediate in the citric acid cycle, ...

pickles Pickle, pickled or Pickles may refer to: Food * Pickle, a food that has undergone pickling * Pickled cucumber * Pickle, a sweet, vinegary pickled chutney popular in Britain, such as Branston Pickle, also known as "sweet pickle" or "ploughman's ...

(

condiment A condiment is a preparation that is added to food, typically after cooking, to enhance the Flavoring, flavour, to complement the dish or to impart a specific flavor. Such specific flavors generally add sweetness or pungency, or sharp or piquant ...

s, and frozen yogurt toppings. It is also used as a preservative in medicines and cosmetics. Under these conditions it is converted into

(E210), which is

bacteriostatic A bacteriostatic agent or bacteriostat, abbreviated Bstatic, is a biological or chemical agent that stops bacteria from reproducing, while not necessarily killing them otherwise. Depending on their application, bacteriostatic antibiotics, disinfec ...

and fungistatic. Benzoic acid is generally not used directly due to its poor water solubility. Concentration as a food preservative is limited by the FDA in the U.S. to 0.1% by weight. Sodium benzoate is also allowed as an animal food additive at up to 0.1%, per the Association of American Feed Control Officials. Sodium benzoate has been replaced by potassium sorbate in the majority of soft drinks in the

United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Northwestern Europe, off the coast of European mainland, the continental mainland. It comprises England, Scotlan ...

. In the 19th century, sodium benzoate as a food ingredient was investigated by Harvey W. Wiley with his 'Poison Squad' as part of the

US Department of Agriculture The United States Department of Agriculture (USDA) is an executive department of the United States federal government that aims to meet the needs of commercial farming and livestock food production, promotes agricultural trade and producti ...

. This led to the 1906

Pure Food and Drug Act The s:Pure Food and Drug Act of 1906, Pure Food and Drug Act of 1906, also known as the Wiley Act and Harvey Washington Wiley, Dr. Wiley's Law, was the first of a series of significant consumer protection laws enacted by the United States Con ...

, a key event in the early history of food regulation in the United States.

In pharmaceuticals

Sodium benzoate is used as a treatment for urea cycle disorders due to its ability to bind amino acids. This leads to excretion of these amino acids and a decrease in ammonia levels. Recent research shows that sodium benzoate may be beneficial as an add-on therapy (1 gram/day) in

schizophrenia Schizophrenia () is a mental disorder characterized variously by hallucinations (typically, Auditory hallucination#Schizophrenia, hearing voices), delusions, thought disorder, disorganized thinking and behavior, and Reduced affect display, f ...

.Add-on Treatment of Benzoate for Schizophrenia A Randomized, Double-blind, Placebo-Controlled Trial of d-Amino Acid Oxidase Inhibitor
December 2013 Total Positive and Negative Syndrome Scale scores dropped by 21% compared to placebo. Sodium benzoate, along with phenylbutyrate, is used to treat

hyperammonemia Hyperammonemia, or high ammonia levels, is a metabolic disturbance characterised by an excess of ammonia in the blood. Severe hyperammonemia is a dangerous condition that may lead to brain injury and death. It may be primary or secondary. Ammoni ...

. Sodium benzoate, along with

caffeine Caffeine is a central nervous system (CNS) stimulant of the methylxanthine chemical classification, class and is the most commonly consumed Psychoactive drug, psychoactive substance globally. It is mainly used for its eugeroic (wakefulness pr ...

, is used to treat postdural puncture headache, respiratory depression associated with overdosage of

narcotics The term narcotic (, from ancient Greek ναρκῶ ''narkō'', "I make numb") originally referred medically to any psychoactive compound with numbing or paralyzing properties. In the United States, it has since become associated with opiates ...

, and with

ergotamine Ergotamine, sold under the brand name Ergomar among others, is an ergopeptine and part of the ergot family of alkaloids; it is structurally and biochemically closely related to ergoline. It is structurally similar to several neurotransmitter ...

to treat vascular headache.

Other uses

Sodium benzoate is also used in

fireworks Fireworks are Explosive, low explosive Pyrotechnics, pyrotechnic devices used for aesthetic and entertainment purposes. They are most commonly used in fireworks displays (also called a fireworks show or pyrotechnics), combining a large numbe ...

as a fuel in whistle mix, a powder that emits a whistling noise when compressed into a tube and ignited.

Mechanism of food preservation

The mechanism starts with the absorption of benzoic acid into the cell. If the intracellular pH falls to 5 or lower, the anaerobic fermentation of

glucose Glucose is a sugar with the Chemical formula#Molecular formula, molecular formula , which is often abbreviated as Glc. It is overall the most abundant monosaccharide, a subcategory of carbohydrates. It is mainly made by plants and most algae d ...

through phosphofructokinase decreases sharply, which inhibits the growth and survival of microorganisms that cause food spoilage.

Health and safety

In the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

, sodium benzoate is designated as

generally recognized as safe Generally recognized as safe (GRAS) is a United States Food and Drug Administration (FDA) designation that a chemical or substance added to food is considered safe by experts under the conditions of its intended use. An ingredient with a GRAS d ...

(GRAS) by the

Food and Drug Administration The United States Food and Drug Administration (FDA or US FDA) is a List of United States federal agencies, federal agency of the United States Department of Health and Human Services, Department of Health and Human Services. The FDA is respo ...

. The International Programme on Chemical Safety found no adverse effects in rats at doses of 647–825 mg/kg of body weight per day. Cats have a significantly lower tolerance against benzoic acid and its

salts In chemistry, a salt or ionic compound is a chemical compound consisting of an assembly of positively charged ions ( cations) and negatively charged ions (anions), which results in a compound with no net electric charge (electrically neutral). ...

than rats and mice. The human body rapidly clears sodium benzoate by combining it with

glycine Glycine (symbol Gly or G; ) is an amino acid that has a single hydrogen atom as its side chain. It is the simplest stable amino acid. Glycine is one of the proteinogenic amino acids. It is encoded by all the codons starting with GG (G ...

to form

hippuric acid Hippuric acid (Greek language, Gr. ''hippos'', horse, ''ouron'', urine) is a carboxylic acid and organic compound. It is found in urine and is formed from the combination of benzoic acid and glycine. Levels of hippuric acid rise with the consumpt ...

which is then excreted. The metabolic pathway for this begins with the conversion of benzoate by butyrate-CoA ligase into an intermediate product, benzoyl-CoA, which is then metabolized by glycine ''N''-acyltransferase into hippuric acid.

Association with benzene in soft drinks and pepper sauces

In combination with

ascorbic acid Ascorbic acid is an organic compound with formula , originally called hexuronic acid. It is a white solid, but impure samples can appear yellowish. It dissolves freely in water to give mildly acidic solutions. It is a mild reducing agent. Asco ...

(vitamin C, E300), sodium benzoate and potassium benzoate may form

. In 2006, the Food and Drug Administration tested 100 beverages available in the United States that contained both ascorbic acid and benzoate. Four had benzene levels that were above the 5 ppb

Maximum Contaminant Level Maximum contaminant levels (MCLs) are standards that are set by the United States Environmental Protection Agency (EPA) for drinking water quality.Joseph Cotruvo, Victor Kimm, Arden Calvert“Drinking Water: A Half Century of Progress.”EPA Alumn ...

set by the Environmental Protection Agency for drinking water. Most of the beverages that tested above the limit have been reformulated and subsequently tested below the safety limit. Heat, light and shelf life can increase the rate at which benzene is formed. Hot peppers naturally contain vitamin C ("nearly as much as in one orange") so the observation about beverages applies to pepper sauces containing sodium benzoate, like Texas Pete.

ADHD and hyperactivity

Research published, including in 2007 for the UK's

Food Standards Agency The Food Standards Agency is a non-ministerial government department of the Government of the United Kingdom. It is responsible for protecting public health in relation to food in England, Wales and Northern Ireland. It is led by a board appoin ...

(FSA) suggests that certain artificial colors, when paired with sodium benzoate, may be linked to hyperactive behavior and other ADHD symptoms. The results were inconsistent regarding sodium benzoate, so the FSA recommended further study.Food Standards Agency issues revised advice on certain artificial colours
6 September 2007Food Colorings and Hyperactivity
"Myomancy" 7 September 2007Agency revises advice on certain artificial colours
, Food Standards Agency, 11 September 2007 The Food Standards Agency concluded that the observed increases in hyperactive behavior, if real, were more likely to be linked to the artificial colors than to sodium benzoate. The report's author, Jim Stevenson from Southampton University, said: "The results suggest that consumption of certain mixtures of artificial food colours and sodium benzoate preservative are associated with increases in hyperactive behaviour in children. . . . Many other influences are at work but this at least is one a child can avoid."

Compendial status

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 involve ...

European Pharmacopoeia The ''European Pharmacopoeia'' (''Pharmacopoeia Europaea'', ''Ph. Eur.'') is a major regional pharmacopoeia which provides common quality standards throughout the pharmaceutical industry in Europe to control the quality of Pharmaceutical drug, ...

Food Chemicals Codex The Food Chemicals Codex (FCC) is a collection of internationally recognized standards for the purity and identity of food ingredients. Scope The FCC features more than 1,250 monographs, including food-grade chemicals, processing aids, foods (suc ...

* Japanese Pharmacopoeia *

United States Pharmacopeia The ''United States Pharmacopeia'' (''USP'') is a pharmacopeia (compendium of drug information) for the United States published annually by the over 200-year old United States Pharmacopeial Convention (usually also called the USP), a nonprofi ...

References

External links

International Programme on Chemical Safety - Benzoic Acid and Sodium Benzoate report
*

{{DEFAULTSORT:Sodium Benzoate Antiseptics Benzoates Preservatives Organic sodium salts E-number additives .