SODIUM BENZOATE = E211 = Benzoate of Soda = Benzoic acid, sodium salt

EC / List no.: 208-534-8
CAS no.: 532-32-1

Sodium benzoate is widely used as a preservative in food, medicine, cosmetics and animal feeds. It is used in the treatment of hyperammonemia and urea cycle disorders. It is used in the fireworks as a fuel in whistle mix. It is also used in the preparation of toothpaste and mouthwashes. It finds application in most of the acidic foods such as salad dressings (vinegar), carbonated drinks (carbonic acid), jams and fruit juices (citric acid), pickles (vinegar), and condiments.

Hygroscopic. Incompatible with alkalis, mineral acids and strong oxidizing agents.

Sodium benzoate is a substance which has the chemical formula C6H5COONa. 
Sodium benzoate is a widely used food pickling agent, with an E number of E211. 

Sodium benzoate is a food preservative which prevents decomposition of food by preventing the growth of fungi or bacteria

Sodium benzoate is a preservative added to some sodas, packaged foods, and personal care products to prolong shelf life.
Sodium benzoate is food preservative that inhibits microbial growth
Sodium benzoate is also used as a cosmetic preservative to provide protection against the growth and proliferation of fungi and bacteria in products.

Sodium benzoate is an organic sodium salt resulting from the replacement of the proton from the carboxy group of benzoic acid by a sodium ion.

Sodium benzoate is produced by the neutralization of benzoic acid with sodium bicarbonate, sodium carbonate, or sodium hydroxide

Sodium Benzoate has a long history of use as a globally trusted, nature identical preservative. 
Sodium Benzoate is used to safely and effectively inhibit microbial growth in foods, beverages, cosmetics, toiletries, and pharmaceuticals up to pH 6.5.

Sodium benzoate is used as an antifungal preservative in cosmetics and in food under the name E211. It is therefore very effective against fungi, yeasts and bacteria. It is made quite easily with soda, water and benzoic acid. It is found naturally in some fruits such as plums, prunes or apples. It is authorized in organic.

Application Group /Application: Description    

Corrosion inhibition: Sodium Benzoate is useful in protecting the metal containers used for Agricultural chemical solutions    

Corrosion Inhibition: Sodium Benzoate is a Corrosion inhibition for steel, zinc, copper, copper alloys, soldered joints, aluminum and aluminum alloys    

Preservative for carbonated and still beverages and juice, Orange juice products, Yucca juice extract.    

Household Care    
Corrosion inhibition: Sodium Benzoate is useful in protecting the metal containers used for Household products, Waxes, Polishes and Aerosol Products.    

Corrosion inhibition    
Sodium Benzoate is used in Paper wrappers to inhibit corrosion of Tin, Steel, Chrome Plated and Galvanized Surfaces even in humid environments.    

Pharmaceutical & Medical    
Products with USP/EP Certification    
Sodium Benzoate is used in topical formulations for the treatment of lice and scabies and in formulations to repel insects.    

Polyolefin Manufacture    
Sodium Benzoate is is Nucleating agent for polyolefin manufacture.    

Preferred IUPAC name: Sodium benzoate
Other names: E211, benzoate of soda
CAS Number: 532-32-1 check

Chemical formula: C7H5NaO2
Molar mass: 144.105 g·mol−1
Appearance: white or colorless crystalline powder
Odor: odorless
Density: 1.497 g/cm3
Melting point: 410 °C (770 °F; 683 K)

Solubility in water: 62.69 g/100 mL (0 °C)
62.78 g/100 mL (15 °C)
62.87 g/100 mL (30 °C)
71.11 g/100 mL (100 °C)[1]

Solubility: soluble in liquid ammonia, pyridine

Solubility in methanol: 8.22 g/100 g (15 °C)
7.55 g/100 g (66.2 °C)[1]

Solubility in ethanol    2.3 g/100 g (25 °C)
8.3 g/100 g (78 °C)
Solubility in 1,4-Dioxane: 0.818 mg/kg (25 °C)

Sodium benzoate is a common food preservative and a mold inhibitor. It is most effective in low acid foods and beverages and baked goods such as breads, cakes, pies, tortillas and many others.1

Benefits of sodium benzoate include its activity against:


Sodium benzoate is a helper ingredient that helps to make the products stay nice longer, aka preservative. Sodium benzoate works mainly against fungi. 

It’s pH dependent and works best at acidic pH levels (3-5). It’s not strong enough to be used in itself so it’s always combined with something else, often with potassium sorbate.

Sodium benzoate is the sodium salt of benzoic acid and exists in this form when dissolved in water. Sodium benzoate can be produced by reacting sodium hydroxide with benzoic acid.

Sodium benzoate is produced by the neutralization of benzoic acid,  which is itself produced commercially by partial oxidation of toluene with oxygen.

Natural occurrence
Benzoic acid, its salts like sodium benzoate and its esters are found in many natural food sources.
Fruits and vegetables can be rich sources, particularly berries such as cranberry and bilberry. 
Other sources include seafood, such as prawns, and dairy products like milk, cheese, and yogurt.

Sodium benzoate is a preservative, with the E number E211. 
It is most widely used in acidic foods such as salad dressings (i.e. acetic acid in vinegar), carbonated drinks (carbonic acid), jams and fruit juices (citric acid), pickles (acetic acid), condiments, and frozen yogurt toppings. It is also used as a preservative in medicines and cosmetics.[5][6] Under these conditions it is converted into benzoic acid (E210), which is bacteriostatic 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.[7] Sodium benzoate is also allowed as an animal food additive at up to 0.1%, per the Association of American Feed Control Officials.[8] Sodium benzoate has been replaced by potassium sorbate in the majority of soft drinks in the United Kingdom.[9]

Sodium benzoate was one of the chemicals used in 19th century industrialised food production that was investigated by Dr. Harvey W. Wiley with his famous 'Poison Squad' as part of the US Department of Agriculture. 
This led up to the 1906 Pure Food and Drug Act, a landmark event in the early history of food regulation in the United States.

Pharmaceutical applications
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. 

Sodium benzoate, along with caffeine, is used to treat postdural puncture headache, respiratory depression associated with overdosage of narcotics,[17][18] and with ergotamine to treat vascular headache.

Other uses
Sodium benzoate is also used in fireworks 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 through phosphofructokinase decreases sharply, which inhibits the growth and survival of microorganisms that cause food spoilage.

Health and safety

1909 Heinz advertisement against sodium benzoate
In the United States, sodium benzoate is designated as generally recognized as safe (GRAS) by the Food and Drug Administration.
The International Programme on Chemical Safety found no adverse effects in humans at doses of 647–825 mg/kg of body weight per day.

Cats have a significantly lower tolerance against benzoic acid and its salts than rats and mice.

The human body rapidly clears sodium benzoate by combining it with glycine to form hippuric acid 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
Main article: Benzene in soft drinks
In combination with ascorbic acid (vitamin C, E300), sodium benzoate and potassium benzoate may form benzene. 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 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.

Sodium benzoate is best known as a preservative used in processed foods and beverages to extend shelf life, though it has several other uses.

It’s an odorless, crystalline powder made by combining benzoic acid and sodium hydroxide. 
Benzoic acid is a good preservative on its own, and combining it with sodium hydroxide helps it dissolve in products.

Sodium benzoate does not occur naturally, but benzoic acid is found in many plants, including cinnamon, cloves, tomatoes, berries, plums, apples, and cranberries (2Trusted Source).

Additionally, certain bacteria produce benzoic acid when fermenting dairy products like yogur

Various Uses in Different Industries
Aside from its use in processed foods and beverages, sodium benzoate is also added to some medicines, cosmetics, personal care products, and industrial products.

Here’s a closer look at its many functions.

Foods and Beverages
Sodium benzoate is the first preservative the FDA allowed in foods and still a widely used food additive. 
It’s classified as Generally Recognized As Safe (GRAS), meaning that experts consider it safe when used as intended.

It’s approved internationally as a food additive and is assigned the identifying number 211. 
For example, it’s listed as E211 in European food products.

Sodium benzoate inhibits the growth of potentially harmful bacteria, mold, and other microbes in food, thus deterring spoilage. 
It’s particularly effective in acidic foods (6Trusted Source).

Therefore, it’s commonly used in foods, such as soda, bottled lemon juice, pickles, jelly, salad dressing, soy sauce, and other condiments.

Sodium benzoate is used as a preservative in some over-the-counter and prescription medications, particularly in liquid medicines like cough syrup.

Additionally, it can be a lubricant in pill manufacturing and makes tablets transparent and smooth, helping them break down rapidly after you swallow them.

Lastly, larger amounts of sodium benzoate may be prescribed to treat elevated blood levels of ammonia. 
Ammonia is a byproduct of protein breakdown, and blood levels may become dangerously high in certain medical conditions.

Other Uses
Sodium benzoate is commonly used as a preservative in cosmetics and personal care items, such as hair products, baby wipes, toothpaste, and mouthwash (2Trusted Source).

It also has industrial uses. One of its biggest applications is to deter corrosion, such as in coolants for car engines.

What’s more, it may be used as a stabilizer in photo processing and to improve the strength of some types of plastic.

Sodium benzoate has been used in a wide variety of products because of its antimicrobial and flavor characteristics. 
Sodium benzoate is the most widely used food preservative in the world, being incorporated into both food and soft drink products. 
Sodium benzoate is used in margarine, salsas, maple syrups, pickles, preserves, jams, and jellies. 
Almost every diet soft drink contains sodium benzoate, as do some wine coolers and fruit juices. 
Sodium benzoate is also used in personal care products like toothpaste, dentifrice cleaners, and mouthwashes. 
As a preservative, sodium benzoate has the advantage of low cost. 
A drawback is its astringent taste that can be avoided by using lower levels with another preservative like potassium sorbate.

In addition to its use in food, it is used as an intermediate during the manufacture of dyes. 
Sodium benzoate is an antiseptic medicine and a rust and mildew inhibitor. 
Sodium benzoate is also used in tobacco and pharmaceutical preparations. 
In the free-acid form, Sodium benzoate is used as a fungicide. 
A relatively recent use for sodium benzoate is as a corrosion inhibitor in engine coolant systems. 
Sodium benzoate has recently been incorporated into plastics, like polypropylene, where it has been found to improve clarity and strength.

Sodium benzoate

Although undissociated benzoic acid is the more effective antimicrobial agent for preservation purposes, sodium benzoate is used preferably, as it is about 200 times more soluble than benzoic acid.

About 0.1% is usually sufficient to preserve a product that has been properly prepared and adjusted to pH 4.5 or below (Chipley, 1983).

A major market for sodium benzoate is as a preservative in the soft drink industry, as a result of the demand for high-fructose corn syrup in carbonated beverages. 
Sodium benzoate is also widely used as a preservative in pickles, sauces, and fruit juices (Srour, 1998).

Benzoic acid and sodium benzoate are used as antimicrobial agents in edible coatings (Baldwin et al., 1995).

Sodium benzoate is also used in pharmaceuticals for preservation purposes (up to 1.0% in liquid medicines) and for therapeutic regimens in the treatment of patients with urea cycle enzymopathies 

Possibly the largest use of sodium benzoate, accounting for 30-35% of the total demand (about 15 000 tonnes of benzoic acid), is as an anticorrosive, particularly as an additive to automotive engine antifreeze coolants and in other waterborne systems (Scholz & Kortmann, 1991; Srour, 1998). 
A new use is the formulation of sodium benzoate into plastics such as polypropylene, to improve strength and clarity (BFGoodrich Kalama Inc., 1999). 
Sodium benzoate is used as a stabilizer in photographic baths/processing (BUA, 1995).

Sodium benzoate Chemical Properties, Uses and Production

Sodium benzoate, also known as benzoic acid sodium, is commonly used as food preservatives in food industry, odorless or with slight smell of benzoin, and tastes sweet astringency. Stable in air, can absorb moisture in open air. It’s naturally found in blueberry, apple, plum, cranberry, prunes, cinnamon and cloves, with weaker antiseptic performance than benzoic acid. Antiseptic performance of 1.180g sodium benzoate is equivalent of about 1g benzoic acid. In acidic environment, sodium benzoate have obvious inhibitory effect on a variety of microorganisms: when pH is at 3.5, 0.05% solution can completely inhibit the growth of yeast; while when pH is above 5.5, it has poor effect on a lot of mold and yeast; hardly has any effect in alkaline solution. After sodium benzoate enters into the body, in the process of biotransformation, it would combine with glycine to be uric acid, or combine with glucuronic acid to be glucosiduronic acid, and all to be eliminated from the body in urine, not to accumulate in the body
As long as it is within the scope of the normal dosage, it would be harmless to the human body, and it is a safe preservatives. It also can be used for carbonated beverages, concentrated juice, margarine, chewing gum base, jam, jelly, soy sauce, etc. Human acceptable daily intake (ADI) < 5 mg/kg body weight (take benzoic acid as calculation basis).

Sodium benzoate has big lipophilicity, and it is easy to penetrate cell membrane into the cells, interfere in permeability of cell membrane, and inhibit cell membrane’s absorption of amino acids; cause Ionization acidification of alkaline storage in the cell when entering into, inhibit activity of respiratory enzymes, and stop condensation reaction of acetyl coenzyme A, and thereby achieve the purpose of food antiseptic.
The above information is edited by the Chemicalbook He Liaopu.

Chemical properties
White crystals or granules, or colorless powder, with sweet astringency. Soluble in water, ethanol, glycerol and methanol.

1. Sodium benzoate is also an important preservative of acid type food. It transforms into effective form of benzoic acid during application. See benzoic acid for application range and dosage. In addition, it also can be used as fodder preservative.
2. Preservatives; antimicrobial agent.
3. Sodium benzoate agent is a very important preservative of acid type fodder. It transforms into effective form of benzoic acid during application. See benzoic acid for application range and dosage. In addition, it also can be used as food preservative.
4. Used in the research of pharmaceutical industry and plant genetic, also used as dye intermediates, fungicide and preservatives.
5. The product is used as food additive (preservative), fungicide in pharmaceutical industry, dye mordant, plasticizer in plastic industrial, and also used as organic synthetic intermediate of spices and others.

Content Analysis
Take dried sample 1.5g into a 250ml conical flask, dissolve it with 25ml water, and then add 50ml ether and bromophenol.

ADI 0~5mg/kg (take benzoic acid as calculation basis, total value of ADI including benzoic acid and its salts and esters; FAO/WHO, 2001).
LD50 4070mg/kg (rats, by oral).

Production methods
1. Neutralized by benzoic acid and sodium bicarbonate. Put water and sodium bicarbonate into the neutralizing pot, boil it and make it dissolved into sodium bicarbonate solution. Mix it with benzoic acid until PH value of the reaction solution reaches to 7-7.5. Heat it to emit over carbon dioxide, and then add active carbon to decolorize it for half an hour. Do suction filtration, after filtrate gets concentrated, put it into flaker tray, dry it to be sheets in the drum, crush it, and then sodium benzoate is made. Consumption rate of benzoic acid (99.5%) 1045kg/t and sodium bicarbonate (98%) 610kg/t.
2. Use 32% soda solution to neutralize benzoic acid in the pot to reach PH value of 7.5, and neutralization temperature is 70℃. Use 0.3% active carbon to decolorize the neutralized solution, vacuum filter it, concentrate, dry it and then it comes to powdered sodium benzoate.
3. To get it by toluene oxidation made benzoic acid reacting with sodium bicarbonate, sodium carbonate or sodium hydroxide.

Sodium benzoate has the chemical formula NaC7H5O2; it is a widely used food preservative, with E number E211. It is the sodium salt of benzoic acid and exists in this form when dissolved in water. It can be produced by reacting sodium hydroxide with benzoic acid.

Chemical Properties
Benzoic acid is almost odorless or exhibits a sweet, faint, balsamic odor and a sweet–sour to acrid taste. For a detailed description, refer to Burdock (1997).

Chemical Properties
white crystalline powder

Chemical Properties
Sodium benzoate is a white crystalline solid. It is odorless and nonflammable
Chemical Properties
Sodium benzoate occurs as a white granular or crystalline, slightly hygroscopic powder. It is odorless, or with faint odor of benzoin and has an unpleasant sweet and saline taste.

Benzoic acid occurs naturally in many plants and in animals. The salt is not found to occur naturally.

Sodium benzoate is a preservative. It is bacteriostatic and fungistatic under acidic conditions. It is most widely used in acidic foods such as salad dressings (vinegar), carbonated drinks (carbonic acid), jams and fruit juices (citric acid), pickles (vinegar), and condiments. It is also used as a preservative in medicines and cosmetics. As a food additive, sodium benzoate has the E number E211.
It is also used in fireworks as a fuel in whistle mix, a powder that emits a whistling noise when compressed into a tube and ignited. The fuel is also one of the fastest burning rocket fuels and provides a lot of thrust and smoke. It does have its downsides: there is a high danger of explosion when the fuel is sharply compressed because of the fuel's sensitivity to impact.

Sodium Benzoate is a preservative that is the sodium salt of benzoic acid. it converts to benzoic acid, which is the active form. it has a solubility in water of 50 g in 100 ml at 25°c. sodium benzoate is 180 times as soluble in water at 25°c as is the parent acid. the optimum functionality occurs between ph 2.5 and 4.0 and it is not recom- mended above ph 4.5. it is active against yeasts and bacteria. it is used in acidic foods such as fruit juices, jams, relishes, and bever- ages. its use level ranges from 0.03 to 0.10%.


A benzene compound used as a synthetic reagent.

Antimicrobial agent, flavoring agent and adjuvant in food; not to exceed a maximum level of 0.1% in food (21 CFR, 184.1733, 582.3733). Antifungal and bacteriostatic preservative in pharmaceuticals at concentrations of ~0.1%. Clinical reagent (bilirubin assay).

Sodium benzoate is a non-toxic, organic salt preservative that is particularly effective against yeast, with some activity against molds and bacteria. It is generally used in concentrations of 0.1 to 0.2 percent.

Sodium benzoate is antimicrobial preservative in foods, e.g. margarine and artificially sweetened fruit preserves. Flavouring agent and adjuvant Sodium benzoate is a preservative. It is bacteriostatic and fungistatic under acidic conditions. It is used most prevalently in acidic foods such as salad dressings (vinegar), carbonated drinks (carbonic acid), jams and fruit juices (citric acid), pickles (vinegar), and condiments. It is also found in alcohol-based mouthwash and silver polish[citation needed]. It can also be found in cough syrups like Robitussin. Sodium benzoate is declared on a product label as 'sodium benzoate' or E211.

ChEBI: An organic sodium salt resulting from the replacement of the proton from the carboxy group of benzoic acid by a sodium ion.

Production Methods
Sodium benzoate is prepared by adding benzoic acid to a hot concentrated solution of sodium carbonate until effervescence ceases. The solution is then evaporated, cooled and allowed to crystallize or evaporate to dryness, and then granulated.
Production Methods
Prepared by the treatment of benzoic acid with either sodium carbonate or sodium bicarbonate.

sodium benzoate: An either colourlesscrystalline or white amorphouspowder, C6H5COONa, soluble inwater and slightly soluble in ethanol.It is made by the reaction of sodiumhydroxide with benzoic acid and isused in the dyestuffs industry and asa food preservative. It was formerlyused as an antiseptic.

Produced by the neutralization of benzoic acid with sodium bicarbonate, sodium carbonate or sodium hydroxide.

Use in foods limited to 0.1%.
Pharmaceutical Applications
Sodium benzoate is used primarily as an antimicrobial preservative in cosmetics, foods, and pharmaceuticals. It is used in concentrations of 0.02–0.5% in oral medicines, 0.5% in parenteral products, and 0.1–0.5% in cosmetics. The usefulness of sodium benzoate as a preservative is limited by its effectiveness over a narrow pH range.
Sodium benzoate is used in preference to benzoic acid in some circumstances, owing to its greater solubility. However, in some applications it may impart an unpleasant flavor to a product. Sodium benzoate has also been used as a tablet lubricant at 2–5% w/w concentrations. Solutions of sodium benzoate have also been administered, orally or intravenously, in order to determine liver function.

Safety Profile
Poison by subcutaneous and intravenous routes. Moderately toxic by ingestion, intramuscular, and intraperitoneal routes. An experimental teratogen. Experimental reproductive effects. Mutation data reported. Larger doses of 8-10 g by mouth may cause nausea and vomiting. Small doses have little or no effect. Combustible when exposed to heat or flame. When heated to decomposition it emits toxic fumes of Na2O. See also BENZOIC ACID.

Ingested sodium benzoate is conjugated with glycine in the liver to yield hippuric acid, which is excreted in the urine. Symptoms of systemic benzoate toxicity resemble those of salicylates. Whereas oral administration of the free-acid form may cause severe gastric irritation, benzoate salts are well tolerated in large quantities: e.g. 6 g of sodium benzoate in 200mL of water is administered orally as a liver function test.
Clinical data have indicated that sodium benzoate can produce nonimmunological contact urtcaria and nonimmunological immediate contact reactions. However, it is also recognized that these reactions are strictly cutaneous, and sodium benzoate can therefore be used safely at concentrations up to 5%. However, this nonimmunological phenomenon should be considered when designing formulations for infants and children.
Other adverse effects include anaphylaxis and urticarial reactions, although a controlled study has shown that the incidence of urticaria in patients given benzoic acid is no greater than that with a lactose placebo.
It has been recommended that caffeine and sodium benzoate injection should not be used in neonates; however, sodium benzoate has been used by others in the treatment of some neonatal metabolic disorders. It has been suggested that there is a general adverse effect of benzoate preservatives on the behavior of 3-yearold children, which is detectable by parents, but not by a simple clinical assessment.
The WHO acceptable daily intake of total benzoates, calculated as benzoic acid, has been estimated at up to 5 mg/kg of bodyweight.
LD50 (mouse, IM): 2.3 g/kg
LD50 (mouse, IV): 1.4 g/kg
LD50 (mouse, oral): 1.6 g/kg
LD50 (rabbit, oral): 2.0 g/kg
LD50 (rat, IV): 1.7 mg/kg
LD50 (rat, oral): 4.1 g/kg

In combination with ascorbic acid (vitamin C, E300), sodium benzoate and potassium benzoate form benzene, a known carcinogen. However, in most beverages that contain both, the benzene levels are below those considered dangerous for consumption. Heat, light and shelf life can affect the rate at which benzene is formed.

Potential Exposure
Sodium benzoate is used as a food and feed additive, flavor, packaging material; pharmaceutical; preservative for food products and tobacco; anti-fungal agent; antiseptic, rust, and mildew inhibitor; intermediate in the manufacture of dyes. Used as a human hygiene biocidal product.

Aqueous solutions may be sterilized by autoclaving or filtration. The bulk material should be stored in a well-closed container, in a cool, dry place.

UN2811 Toxic solids, organic, n.o.s., Hazard Class: 6.1; Labels: 6.1-Poisonous materials, Technical Name Required.

Purification Methods
Crystallise it from EtOH (12mL/g). [Beilstein 9 IV 27.]

Mechanism of food preservation
The mechanism starts with the absorption of benzoic acid into the cell. If the intracellular pH changes to 5 or lower, the anaerobic fermentation of glucose through phosphofructokinase is decreased by 95 %, thereby inhibiting the growth and survival of micro-organisms that cause food spoilage.

Incompatible with quaternary compounds, gelatin, ferric salts, calcium salts, and salts of heavy metals, including silver, lead, and mercury. Preservative activity may be reduced by interactions with kaolin or nonionic surfactants.

Dust may form explosive mixture with air. Incompatible with oxidizers (chlorates, nitrates, peroxides, permanganates, perchlorates, chlorine, bromine, fluorine, etc.); contact may cause fires or explosions. Keep away from alkaline materials, strong bases, strong acids, oxoacids, epoxides.

Regulatory Status
GRAS listed. Accepted as a food additive in Europe. Included in the FDA Inactive Ingredients Database (dental preparations; IM and IV injections; oral capsules, solutions and tablets; rectal; and topical preparations). Included in nonparenteral medicines licensed in the UK. Included in the Canadian List of Acceptable Non-medicinal Ingredients.

Benzoan sodny
Benzoate of soda
Benzoate sodium
Benzoesaeure (na-salz)
Benzoic acid, sodium salt
Benzoic acid, sodium salt (1:1)
Natrium benzoicum
Sodium benzoate
Sodium Benzoate
Sodium benzoate
sodium benzoate

Translated names
Benzoat de sodiu (ro)
Benzoate de sodium (fr)
Benzoato de sodio (es)
Benzoato de sódio (pt)
Benzoato di sodio (it)
Benzoesan sodu (pl)
Benzoát sodný (cs)
Benzoát sodný (sk)
Benżoat tas-sodju (mt)
Naatriumbensoaat (et)
Natrijev benzoat (hr)
Natrijev benzoat (sl)
Natrio benzenkarboksilatas (lt)
Natriumbensoat (sv)
Natriumbentsoaatti (fi)
Natriumbenzoaat (nl)
Natriumbenzoat (da)
Natriumbenzoat (de)
Nátrium-benzoát (hu)
Nātrija benzoāts (lv)
Sodium benzoate (no)
Βενζοϊκό νάτριο (el)
Натриев бензоат (bg)

CAS names
Benzoic acid, sodium salt (1:1)

IUPAC names
Benzoic acid sodium salt
Benzoic acid, sodiium salt (1:1)
Benzoic acid, sodium salt
benzoic acid, sodium salt
Benzoic acid, sodium salt (1:1)
Benzoic acid, sodium salt (1:1)

Trade names
Palmarole Mi.Na.08

sodium benzoate
Benzoic acid, sodium salt
Benzoic acid sodium salt
Benzoate sodium
Benzoate of soda
FEMA No. 3025
Benzoic acid, sodium salt (1:1)
Benzoate, sodium
Natrium benzoicum
Caswell No. 746
Benzoan sodny [Czech]
Benzoan sodny
FEMA Number 3025
Sodium benzoate, 99+%, extra pure
Sodium benzoate, 99%, for biochemistry
CCRIS 3921
HSDB 696
Benzoesaeure (na-salz) [German]
Benzoesaeure (na-salz)
Sodium benzoate solution
EINECS 208-534-8
EPA Pesticide Chemical Code 009103
Sodium benzoate [USAN:JAN:NF]
benzoic acid sodium
Sodium Benzoate USP
Sodium Benzoate,(S)
Sodium benzoate (TN)

Sodium benzoate is a preservative that can be found in acidic foods such as salad dressings, carbonated drinks, jams, juices, and condiments. It is also found in mouthwashes, silver polishes, cough syrups, soaps, and shampoos.

• AI3-07835
• Antimol
• Benzoan sodny
• Benzoan sodny [Czech]
• Benzoate of soda
• Benzoate sodium
• Benzoesaeure (na-salz)
• Benzoesaeure (na-salz) [German]
• CCRIS 3921
• Caswell No. 746
• EINECS 208-534-8
• EPA Pesticide Chemical Code 009103
• FEMA No. 3025
• FEMA Number 3025
• HSDB 696
• Natrium benzoicum
• Sobenate
• Sodium benzoate

What are some products that may contain sodium benzoate?
Body washes
Household products
Pet care

Sodium benzoate is a preservative commonly used in fruit pies, jams, beverages, salads, relishes, and sauerkraut—foods that have an acidic pH. 
Chemical preservatives such as sodium benzoate are frequently used in processed foods to prevent the growth of bacteria, yeast, or other unwanted microorganisms that could spoil your food.

When sodium benzoate is combined with water, benzoic acid is produced. 
Benzoic acid is the active form of the preservative—the form that protects foods. 
Benzoic acid is also found naturally in some fruits, such as cranberries, plums, and apples.

Sodium benzoate is a salt of benzoic acid that is found naturally in cranberries, prunes, plums, apples, and other fruits.  
In its solid form it is a white, granular or crystalline powder.  
While benzyl alcohol is an organic alcohol with a hydroxyl group (-OH), the related compound benzoic acid has a carboxyl group (-COOH). 
Sodium benzoate is used in a wide variety of cosmetics and personal care products where it acts as a corrosion inhibitor, fragrance ingredient, and preservative.  

As a preservative, sodium benzoate is primarily an anti-fungal agent but also has some effectiveness against bacteria.  
It is not a broad-spectrum preservative for cosmetic use and should be combined with other preservatives.  
Sodium benzoate is often combined with potassium sorbate in low pH products in order to benefit from the ingredients’ synergistic effects against yeast and mold.  
When combined with caffeine, it can have a sunscreen effect and provide UVB protection with antioxidant activity.

While there has been some controversy over the use of sodium benzoate as a food preservative due to its potential to interact with ascorbic acid (a derivative of vitamin C) and produce benzene, the amount of sodium benzoate in foods is so low that it is FDA approved and deemed safe.  
Soft drinks are the main source of sodium benzoate in the diet where the ingredient is limited to a maximum of 0.1% by weight.  
It is absorbed, metabolized and excreted rapidly after ingestion.  
Sodium benzoate is not a toxin or carcinogen on its own, and large amounts of it would have to be consumed, not applied topically, for any adverse effects to be seen. 

So then, is the combination of sodium benzoate and vitamin C in skin care products a potential concern?  
Fortunately, there are ways of formulating these products to prevent a reaction between the two ingredients from occurring.  
Benzene does not form at all in cosmetic products with a high concentration of vitamin C and a low concentration of sodium benzoate, because higher amounts of vitamin C cause it to act as a free radical scavenger rather than react with sodium benzoate.  
Products with a pH of 3 or higher are generally safer in terms of preventing benzene formation, and above a pH of 7 no benzene forms at all.  
Protecting products from light and heat exposure also limits the potential for benzene formation.  
Manufacturers that follow safe practices can effectively prevent the formation of benzene in cosmetic products that also contain vitamin C.  
And for the most part, sodium benzoate is only used in formulas that do not contain significant levels of vitamin C.  

Preservatives are the substances added to food to prevent decompositions by microbial growth or undesirable chemical changes. 
There are many preservatives which are commonly used in food industries including benzoate group, which is used as bacteriostatic and fungistatic in acidic food and drink such as vinegar, carbonated drinks, jams, fruit juice, and condiments. 
Sodium benzoate is commonly used in worldwide food. Nowadays food and drink consumption involve with these preservatives, due to almost products even fresh or dried food are always added preservatives to extend lifespan. Food and Drug Administration (FDA) regulates the amount of food additives allowable in foods or other goods to help ensure safety and reduce the possibility of overconsumption. 
For using benzoate group such as sodium benzoate and potassium benzoate in dairy products such as ice cream, pudding, and yoghurt, FDA allows using sodium benzoate at 300 mg/1 kg. 
As the result of long term intake even though it is small amount, the preservatives may cause harm to consumers within some sickness and in chromosomes level. 
The following adverse effects of food preservatives are nausea, vomiting, diarrhea, rhinitis, bronchospasm, migraine, anaphylaxis, and hyperactivity in children [1].

Sodium benzoate in non-alcoholic carbonated (soft) drinks: Exposure and health risks
Author links open overlay panelS.L.AzumaN.K-A.QuarteyI.W.Ofosu
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There is a serious concern about the use of sodium benzoate in non-alcoholic carbonated (soft) drinks because of its mechanistic ability to convert to benzene, a classified carcinogen. 
It is this concern that drove this study to determine consumer exposures to sodium benzoate and possible health risks from intake of such soft drinks. 
A survey was conducted during which Google Forms were used to collect drink consumption data from 113 consumers including males and females. 
During this same period, 38 varieties of non-alcoholic carbonated (soft) drinks were collected from two major markets in Ghana. 
These drink samples were subsequently subjected to extraction protocols and the levels of sodium benzoate quantified using HPLC. 
Information from the Google Forms together with the quantification of sodium benzoate formed the basis of the determination of exposure of sodium benzoate according to the USEPA protocols. Using the Palisade @Risk software, elements of exposure of sodium benzoate (mg/mL ingested, volume-mL of non-alcoholic carbonated (soft) drink consumed, and body weight-kg of consumers) were integrated and iterated (at 105) to estimate the simulated chronic exposures. 
Simulated risks (hazard quotient, HQ, margin of exposure, MoE, and cancer risk, LTCR) were determined using thresholds obtained from regulatory bodies. 
High levels of sodium benzoate, above the acceptable limit of 150 mg/L based on USEPA recommendations, were detected in 6 (16%) of the 38 non-alcoholic carbonated (soft) drinks sampled. 
The results of the study showed that the concentrations of sodium benzoate ranged from a minimum of 51.0 mg/L to a maximum of 277.0 mg/L. 
It was clear that the consumption patterns of males created relatively high exposures leading to unsurprisingly higher risks compared to female consumers. 
The high-risk indices determined in this study, relative to regulatory thresholds (HQ>1, MoE<104 and LTCR >10−6) are all serious indicators of grave public health concerns. 
These observations emphasize potential benzenes in our food chains and a call for a more forceful monitoring of product quality and safety to ensure adherence to standards.
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Sodium benzoate
Margin of safety
Cancer risk

The use of chemical conserving agents in food and drinks has attracted attention worldwide and attempts have been made to decrease the impacts of these substances on human health and the environment by international and national regulatory authorities [1]. 
Benzoic acid and its salts which are used as food preservatives against fungal and bacterial activity, have been found to present health risks [2]. 
Benzoic acid reacts with ascorbic acid in soft drinks to form benzene, a chemical classified by the IARC as a Group 1 carcinogen [3]. 

A series of epidemiological studies have evidently identified the role of benzene as a leukomogen [4] and have also revealed that persons exposed to 1–2 ppm of benzene over a 40-year period stands a higher risk of developing leukemia and genotoxicity [5]. Furthermore, studies have shown that high concentrations of benzoates and high market storage temperatures enhance benzene formation from benzoic acid in the presence of ascorbic acid [6]. 
There is heightened focus on benzene exposure through consumption of carbonated and non-alcoholic beverages because they have higher sodium benzoate (E211) concentrations relative to other food commodities. 
The increased consumption of non-alcoholic carbonated (soft) drinks in urban areas and cities [7] make the inherent risks posed by the presence of benzene precursors in these products a health concern. 
It has therefore become imperative to consider all the elements that will best aid to assess and judge the risks posed by the presence of this hazard in non-alcoholic carbonated (soft) drinks.
One risk index which can be used to quantify the risk associated with benzene exposure is the hazard quotient (HQ); defined as the ratio of the chronic dietary intake (CDI) to the reference dose of benzene [8]. 

The lifetime risk estimate for developing cancer, another risk index, uses the product of the CDI of human exposures and the potency factor (PF) for the hazard. 
The potency factor which is the risk produced by ingesting an average dose of 1 mg/kg(bw)-d of the hazard over a lifetime, is also referred to as the slope factor and is often obtained from institutional compendia [8]. 
The margin of exposure (MoE), which can also be used to evaluate any inherent risk defined as the ratio between the lower limit benchmark dose (BMDL10) to the estimated daily exposures of the hazard. 
To make concise judgements on the exposure of benzene precursors in consumers, a detailed consumption data covering the elements for determining chronic daily exposures must be analyzed. The elements for determining CDI are integrated as the product of the average daily intake and consumption level, related to exposure frequencies and exposure durations per the averaging time [8]. 
Even though exposure to benzene may be determined using information from a national food consumption database, the reliability of such data may be flawed and this information is virtually non-existent for the subpopulation under study.
For health risk estimates to generate any significant food safety discussions, the estimated values must be compared to established thresholds. 
The European Food Safety Authority (EFSA) and the United States Environmental Protection Agency (USEPA) state that a HQ>1 represents considerable risk and necessitates public health concern [8]. 
In estimating MoE for hazards that are both carcinogenic and genotoxic, EFSA guidelines state that MoE values greater than 10,000 are desired whereas those values lower than 10,000 raise public health concern. 
Similarly in estimating life time cancer risks, the estimated values are compared with the recommended de minimis (10−6) and values greater than this are deemed to imply excess risk of developing cancer [9]. Documenting results from these indices of health risk empower risk communicators and managers to review the preparedness to deal with public safety.
A range of 0–5 mg/kg(bw)-d allowable daily intake (ADI) has been established by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) for benzoic acid and benzoate salts [10]. 
During its 51st meeting, JECFA evaluated intake assessment information of benzoic acid from nine member states to guarantee consumer safety from its intake. 
It was observed that the mean estimated intake of benzoates in reference to specified national maximum limits were below the ADI but exceed the range of use specified in the draft General Standard for Food Additives [11]. It is noteworthy that benzene in such soft drinks do not arise as environmental contaminant but forms as a result of the decomposition reaction gradually going on in the matrix with the passage of time. 
Thus, the longer the product is kept on the shelf, the higher the probability of formation of benzene from its precursors [12].
Internationally, there is no legal standard reference value beyond which benzene poses lifetime cancer risk to consumers. 

However, an Expert report by WHO sets a reference limit of 10 µg/L [13]. 
USEPA also set a 5 µg/L [14] benchmark, while the European Commission has set a limit of 1 µg/L for benzene in non-alcoholic carbonated drinking water [9].
Statistics available from the WHO indicates that in 2015, more than 8.8 million deaths globally were due to cancer and 70% of that number was from low to middle income countries like Ghana [15]. Cancer is the fourth cause of mortality in Ghana, with approximately 16,600 cases reported yearly [16]. 
Diet and disease outcome studies suggest that 20–50% of cancer cases are diet related [17] and thus, dietary intakes require particular attention.
Experts have reported that precursors of benzene such as benzoic acid and sodium benzoate which though are regulated to be used as food additives are often abused. 
It is such misuse that often present several disease outcomes including DNA damage, allergies, hypersensitivity, asthma, urticaria and certain types of cancer [18]. 
It has also been shown to have significant effects on cognitive functions (attention deficit/hyperactivity disorder in children) and causing partial infertility in males [19]. 
These findings have urged many advanced countries to work extensively to determine sodium benzoate and thus, benzene, exposures through non-alcoholic carbonated (soft) drinks intake. 
However, for developing countries such as Ghana, this task faces the challenge of the absence of an updated national food consumption data. 
It is highly unreliable to extrapolate risk values from the risk assessments of benzene exposure from developed countries due to the indisputable variations in non-alcoholic carbonated (soft) drinks formulations, intake patterns and consumption quantities worldwide. 
This necessitates a study to investigate whether the concentrations of benzene precursors, benzoic acid and its salts, in carbonated non-alcoholic carbonated (soft) drinks on the local market are enough to pose carcinogenic or genotoxic health risks.
The objective of this study was to assess the levels of sodium benzoate in non-alcoholic carbonated (soft) drinks available on the local market and quantify risk indices for carcinogenicity and genotoxicity among consumers.

Materials and methods

Sample collection
Samples of non-alcoholic carbonated (soft) drinks produced by both local and international companies were collected from the Makola market, Greater Accra region and the Kejetia market, Ashanti region using a convenient random sampling method. A total of 38 samples consisting of 19 different known brands and consumer stated brands, of non-alcoholic carbonated (soft) drinks containing sodium benzoate (E211), as preservative, were collected and analyzed.
Standards and reagents
Sodium benzoate standard, HPLC grade sodium phosphate, and acetonitrile reagents were obtained from Merck (Darmstadt, Germany).

Study area
The study was conducted in Accra and Kumasi, two principal cities in Ghana. Accra the capital and largest city of Ghana lies on GPS coordinates Latitude 5° 33′ 21.67″ N and Longitude 0 ° 11′ 48.84″ E on the coast of the Gulf of Guinea. It is the most populous city, inhabited by some four million people [20]. Accra's largest market and trading hub is the Makola market with other notable ones being Kaneshie and Madina markets [20]. Kumasi the second largest city, and second most densely populated metropolis is in the Ashanti region and lies between Latitude 6.35°N and 6.40°S, and Longitude 1.30°W and 1.35°E, with a population of about two million according to the 2010 population census [21]. Many people from different regions of Ghana access Kumasi for a number of business activities daily, mainly because it serves as the primary trading center for several commodities [21]. The city has a number of large markets including Bantama and Tafo with Kejetia markets being the largest [21].
Outline of questionnaire and carbonated soft non-alcoholic carbonated (soft) drinks consumption data
A structured questionnaire to collect relevant information was used to capture the intake of non- carbonated (soft) drinks by consumers. It comprised of the number of times respondents consumed these non-alcoholic carbonated (soft) drinks, the volume they consumed, how often they consumed them in a year and the number of years respondents have consumed them. The biodata of the consumers was also captured which included age, weight, gender, religion, work and the level of education. The data obtained from about 113 respondents were captured into Microsoft Excel worksheet for further analysis.

Sample preparation
An ultra-sonic bath was used to degas the samples for 15 min. 
The degassed samples were further filtered through a 0.45 µm filter paper and pipetted into 2 mL amber HPLC vials for analysis.

Determination with HPLC
A Dynamic Absorbance detector coupled to a Cecil-Adept binary pump HPLC (Cambridge, UK) was employed in the HPLC analysis. 
A Waters Column (3.9 × 300 mm, 5 µm) was used and the column oven temperature was set at 40 °C. The mobile phase constituted a sodium phosphate and acetonitrile buffer (60:40 v/v) with a pH 4.4. A flow rate of 1 mL/min was set for the mobile phase, and the bands were detected at 225 nm. A 20 µL volume of the samples and internal standards were injected by the auto sampler into the HPLC for the analysis. The presence of sodium benzoate was detected and quantified as peaks, which were then matched with the standard retention time, and the concentrations of sodium benzoate subsequently quantified.

Quality control
The recovery was determined by spiking different quantities of standard sodium benzoate (20, 50 and 100 µg) in 2 mL deionized water. 
Extraction and purification were done in the same manner for the various sampled non-alcoholic carbonated (soft) drinks. 
The method used was accurate and efficient since the mean recovery obtained was 98% [22]. 
The limit of detection (LOD) was 0.23 µg/g and the limit of quantification (LOQ) was 0.76 µg/g. 
A linear calibration curve was obtained with an R2 = 0.999.
Data analysis
The survey data was aggregated and keyed into a Microsoft Excel and classified according to gender. 
The Palisade @Risk software was then used as a Microsoft Excel add-on to fit the variables that indicate risk to their various distributions. 
The variables included: the product of the hazard concentration (CH) in mg/g, total volume of non-alcoholic carbonated (soft) drinks consumed per day (VD) in mg/L; and exposure frequency (EF) in days/year respondents and exposure duration (ED) in years representing the number of years the non-alcoholic carbonated (soft) drinks has been consumed by the respondent. These were expressed as ratio of respondents’ body weight (BW) in kg and averaging time (AT).

Exposure, expressed as CDI, was estimated using Eq. (1). 
All the variables were fitted to their specific distributions and subsequently iterated 100,000 times using Palisade @RISK (Palisade, 2018) software to determine the CDI.
(1)CDI=CH×VD×EF×EDBW×ATAveraging times of either 30 years or 70 years were used to obtain exposures for both non-carcinogenic or carcinogenic determinations respectively [23].
To properly characterize the tumorigenic and genotoxic effects of dietary exposure to benzene precursors, the margin of exposure (MoE), was determined using Eq. (2).
(2)MoE=BMDL10CDIA BMDL10 (bench mark dose lower limit) of 17.6 mg/kg(bw)-d was adopted for this study [24].
The hazard quotient (HQ), a non-cancer risk measure for systemic toxicity, was estimated using Eq. (3), where a reference dose (RfD) of 4 × 10−3 mg/kg(bw)-d as adopted from USEPA [25].(3)HQ=CDIRfDThe risk of developing cancer during one's lifetime, lifetime cancer risk (LTCR), through dietary exposure to sodium benzoate was estimated based on USEPA protocols using Eq. (4) (3). The potency factor (PF) for benzene 1.5 × 10−2 mg/kg(bw)-d was adopted for this study [25].(4)R=CDI×PFThe carcinogenic risks, and margin of exposure were all iterated 100,000 as before.

Results and discussions
Sodium benzoate levels in non-alcoholic carbonated (soft) drinks

The sodium benzoate concentrations sampled from the non-alcoholic carbonated (soft) drinks in the study area, ranged between a minimum-maximum of 5.1–277 mg/L. 
The 5th, 50th and 95th percentiles of the benzoate concentration were 51.8 mg/L, 131.5 mg/L and 211.3 mg/L respectively (Table 1). 
The 5th and 50th percentile benzoate concentrations fall within the institutionally permissible level of 150 mg/L [14].

Table 1. Statistical distribution of sodium benzoate and elements of exposure in survey respondents.
    Central tendency metrics    Percentiles
    Variable    Statistical distribution    Min    Max    Mean    Mode    5th    50th    95th

Males    Benzoate (mg/L)    Laplace (131.5346,48.9716)    5.1    277.0    131.5    131.2    131.5    51.8    211.3
    VD (L)    Pareto (1.8195,0.2000)    0.2    1.5    0.4    0.2    0.3    0.2    1.0
    EF (days/year)    Uniform (6.8841,370.12)    12.0    365.0    188.5    85.0    188.5    25.1    352.0
    ED (years)    Uniform (4.7101,25.290)    5.0    25.0    15.0    7.9    15.0    5.7    24.3
    BW (kg)    Loglogistic (50.176,23.807,2.8282)    55.0    188.0    79.7    68.6    74.0    58.6    117.6

Females    Benzoate (mg/L)    Laplace (131.5346,48.9716)    5.1    277.0    131.5    131.9    131.5    51.8    211.3
    VD (L)    ExponAlt (0.16686, 0.19612)    0.2    0.9    0.4    0.2    0.3    0.2    0.7
    EF (days/year)    Uniform (3.5952,373.40)    12.0    365.0    188.5    183.0    188.5    22.1    355
    ED (years)    Uniform (4.5238,25.476)    5.0    25.0    15.0    25.0    15.0    5.6    24.4
    BW (kg)    Triang (49,49,94.069)    49.0    90.0    64.0    49.1    62.2    50.1    84.0
The mean benzoate concentration, 131.5 mg/L, for this study was higher than the mean of 70.20 mg/L reported in a study involving 34 different brands of non-alcoholic and fruit juices sampled from markets in Ghana [26]. This value is also higher than a mean reported in England (54 mg/L), Japan (20 mg/L) and Philippines (50 mg/L) [27]. The wide differences in sodium benzoate in non-alcoholic carbonated (soft) drinks may have arisen because of the uniqueness of brands sampled, and also laxity among regulatory measures [28].
The maximum concentration of the benzoate (277 mg/L) for this study was lower relative to the maximum concentration (548 mg/L) obtained in another study conducted in Ghana [26]. Though, lower than the sodium benzoate concentration recorded for studies in the Philippines (2000 mg/L) and Brazil (804 mg/L) [27], the maximum sodium benzoate concentration in this study was higher relative to the maximum reported in studies in Japan (200 mg/L), England (100 mg/L) [27] and Iran (130 mg/L) [29]. Again, the maximum and also the simulated 95th percentile sodium benzoate concentration exceeded acceptable limits however, the frequently occurring (modal) concentrations (131.2 mg/L) was within the acceptable limit (150 mg/L) [30].
Exposure of sodium benzoate in male and female respondents
The non-alcoholic carbonated (soft) drinks consumption data profile of the survey respondents presented in Table 1, show variables that were integrated to obtain the chronic exposures. These variables which include sodium benzoate concentration, volume of non-alcoholic carbonated (soft) drinks (VD), exposure frequency (EF), exposure duration (ED) and body weight (BW), all presented different statistical distributions. Both male and female respondents were exposed to almost the same quantities of the benzoate. The mean exposure values were the same for both genders with marginal variation of the modal benzoate concentration: 131.2 mg/L and 131.9 mg/L for males and females respectively. There was also no significant difference in volume of non-alcoholic carbonated (soft) drinks consumed per day by male and female respondents. However, the maximum volume drank per day and the simulated 95th percentile consumption were different for males and females (Table 1). The exposure frequency was uniformly distributed for both male and female respondents, but females were more frequently exposed (modal value); 183 days/year than males; 85 days/year. 
The exposure duration was also uniformly distributed and followed the pattern of the exposure frequency for males and females. 
Females recorded a higher modal value; 25 years than males; 7.9 years, indicating a longer time of exposure in females (Table 1).
Volume of non-alcoholic carbonated (soft) drinks consumed
The general trend was such that the mean, median, 5th and 95th percentile of volume of non-alcoholic carbonated (soft) drinks consumed per day indicated a similar consumption pattern for both males and females. However some studies have shown that generally, males consume more non-alcoholic carbonated (soft) drinks than females [31,32]
Chronic exposures
The chronic daily intake of the benzoate for consumers with regard to non-cancer and cancer risks ranged from 0.0025 to 82.89 mg/kg(bw)-d (Table 2). 
However, regulatory authorities such as the Human Exposure Characterization of Chemical Substances (HEXPOC) reported human dietary exposure to benzene as varying from 3 to 50 ng/kg(bw)-d [33]. This suggests that the accumulation of benzene, through benzoate ingestion obtained in this current study is relatively high. 
There were differences in the chronic daily intake estimated for both male and female respondents. 
The maximum cancer and non-cancer CDI for male respondents which is extremely high, comparatively (Table 2), might point to an outlier consumer whose intake is too high [34]. The values for CDI leading to non-cancer related health risks for both genders were only marginal relative to the CDI for the cancer related health risks. 
Following this, the modal CDI seems to attribute more risk to males than females (Table 2). 
These exposures might appear to be marginal relative to lethal oral dose of benzene that stands at 125 mg/kg [5] for humans. 
However, it is the chronic exposures that cause genotoxicity and adversely impacts the hematopoietic system [5,35].
Table 2. Probabilistic estimates of chronic dietary non-cancer and cancer exposure, hazard quotient, margin of exposure (MoE) and lifetime cancer risks (LTCR) for respondents.
    Central tendency metrics    Percentiles
    Variable    Min    Max    Mean    Mode    5th    50th    95th
Males    CDI (non-cancer)    0    82.89    0.199    0.014    0.009    0.111    0.598
    CDI (cancer)    0    18.97    0.085    0.005    0.004    0.048    0.256
    Hazard Quotient    0    24.7 × 103    50.03    7.37    2.44    27.68    148.97
    MoE    0    11 × 106    1106.50    142.01    59.67    358.38    3512.78
    LTCR    0    0.61    1.8 × 10−3    5.6 × 10−5    6.2 × 10−5    7.2 × 10−4    3.8 × 10−3
Females    CDI (non-cancer)    0    0.838    0.096    0.0064    0.0058    0.073    0.265
    CDI (cancer)    0    0.395    0.041    0.0032    0.0025    0.031    0.113
    Hazard Quotient    0    222.58    23.94    1.95    1.48    18.18    66.19
    MoE    0    10.2 × 106    1647.16    245.58    145.20    546.00    5616.06
    LTCR    0    6.3 × 10−3    6.1 × 10−4    1.7 × 10−5    3.7 × 10−5    4.7 × 10−4    1.7 × 10−3
Risk characterization
The hazard quotient for all respondents, male and female, except at minimum consumption was above 1 (HQ>1) (Table 2), showing that there are considerable adverse health concerns. 
While the HQ recorded for both males and females at maximum consumption levels may be explained as a possibility of an outlier consumer with high intake, it appears male consumers are relatively at higher risk compared to females (Table 2). The frequently occurring values of hazard quotient for males and females were 7.37 and 1.95 respectively.
The margin of exposure (MoE) in this study, took into account the carcinogenic and genotoxic effects of benzene. 
The maximum MoE for both males and females was > 104, meaning there were very few isolated cases of low public health concern. 
However, there were indications that there were frequently occurring (modal) public adverse health concern (MoE < 104) in the study area for genotoxicity (Table 2). 
Though the results in this study strongly suggest adverse health effect (MoE < 104), other authors reported such MoEs (103–106) as too low to cause public health problems [24].
 However, these authors suggested further studies to be conducted.
For this current study, the lifetime cancer risks from exposures to sodium benzoate in non-alcoholic carbonated (soft) drinks ranged from 3.7 × 10−5 to 0.61. 
As indicated in Table 2, male consumers appear to be at higher risk relative to female consumers. The values obtained for the lifetime cancer risk (LTCR) of the consumers show > 10−6 or 1 out of 1 million (an acceptable risk, de minimis). This indicate that there is a serious public health concern for ingestion of benzoates in non-alcoholic carbonated (soft) drinks. 
The mean lifetime cancer risk (1.8 × 10−3) for male consumers in particular is disturbing (Table 2). In fact, at least 50% of male consumers show a cancer risk of 7 out of 10,000; relative to female consumers who show a risk of 5 out of 10,000. This observation was enforced by the frequently occurring cancer risk of males as 6 out of 100,000; relative to females which was 2 out of 100,000 consumers (Table 2).

The results from this study showed that although males and females are similarly exposed to dietary sodium benzoate through non-alcoholic carbonated (soft) drinks intake, consumption patterns create high exposures in males than in females. Thus, male consumers are unsurprisingly more at risk than female consumers. The high-risk indices relative to regulatory thresholds: HQ >1, MoE<104 and LTCR >10−6, are all serious indicators of grave public health concern of potential benzene in our food chains. 
In this study, the source of dietary exposure to benzene through sodium benzoate consumption was determined only from non-alcoholic carbonated (soft) drinks. 
However, since benzene might not come from such soft drinks only, we must bear in mind that the total exposure might be seriously greater. 
Thus, because benzene tends to accumulate in human tissues over a relatively long period, grave impact on public health is bound to occur.

Policy brief
Sodium benzoate in non-alcoholic carbonated (soft) drinks: exposure and health risks

Non-alcoholic carbonated (soft) drinks containing benzoates has gained worldwide consumption especially among the working class. 
Sadly, studies also show that these benzoates are sources of benzene, which has been classified by experts as a human carcinogen. 
There is evidence to show that these non-alcoholic carbonated beverages present the highest benzene concentrations relative to the quantities found in other foods. 
Thus, long term consumption of such products put consumers at great risk. The problem is further exacerbated in developing economies where lack of standards makes it easier for producers to flood markets with such unsafe products either out of irresponsibility or lack of knowledge. Therefore, this study sought to quantify levels of benzoate salts in non-alcoholic carbonated (soft) drinks and provide a guide by which safety standards in such drinks can be monitored. It is hoped that the results would serve as a guide for policy making and also to fill a knowledge gap for public health practitioners and regulators.
Need to carry out the study
It is very important that this study is periodically carried out in order to monitor compliance to quality and safety benchmarks of non-alcoholic carbonated (soft) drinks. 
These studies would also monitor the distribution of risks across consumers’ non-alcoholic carbonated (soft) drinks consumption habits. 
Similarly, the distribution of exposure and risks among consumers will show the dynamics of safety. 
Again, through such studies, production of these drinks, sampled from the market place would serve to determine quality and safety of drinks that are being consumed. 
This feedback can then be used to control the product safety during production.

Our goal
The goal of this study was to develop capacity for our regulatory institutions to periodically monitor the levels of such carcinogens in our foods, and also to accumulate data which can be used for robust monitoring and evaluation in the long term.
Results obtained

The frequently occurring (mode) sodium benzoate levels in the sampled non-alcoholic carbonated (soft) drinks from the study area was below the threshold set by standards (150 mg/L), though the top 5% distribution of the drinks, show levels above the standards.

Health risks are often probabilistic events expressed in safety indices as: hazard quotient (HQ), representing the ratio of exposures of the chemical ingested (per body weight), to recommended safe exposures (reference dose). HQ is a tool often used to screen for non-cancer related risks. In its application, when the HQ>1, risk is implicated. 
The frequently occurring (mode), and also 50% of consumers sampled in the study area, presented HQ>1, meaning the situation is seriously unsafe for both sexes in connection with non-cancer related health risks.

There is another tool referred to as margin of exposure (MoE). 
It expresses the level of public health concern about safety of chemical exposures. 
This is also often determined as exposures per a defined regulatory reference value. Higher values usually indicate less public health concern. 
This study presented low frequently occurring (mode) MoE indices for both sexes. Lower values were recorded for males relative to females for cancer related toxicities. 
This observation again, show high public adverse health concern.

Regulatory institutions often recommend values of risks approaching zero to be ideal for cancer studies. 
However, this is practically impossible for many reasons including commerce. For scientific or academic purposes however, a risk of 1 person in over 1 million consumers is acceptable. 
This approach is yet another tool used to determine cancer risks directly. 
It is often determined as the product of the exposures of the concentration of the chemical hazard (in this case, benzoate) and its regulatory defined referenced risk factor (benzoate exposed as 1 mg/ kg-d in a lifetime). In this study, there were reportedly frequently occurring(mode) lifetime cancer risks (LTCR) of 6 out of 10 thousand in male consumers, as against 2 out of 10 thousand in female consumers. 
This observation again emphasizes the real threats underlying the consumption of such drinks.

Since the health risk indicators obtained from the study area are significantly greater than the recommended values, there must be a renewed call to intensify safety actions. 
The demand of processed food is growing and this trend requires the application of benzoates as preservatives against microbial growth. 
Thus, the application of sodium benzoates in foods is likely to surge. Unfortunately, food is a matrix containing many elements, some of which may initiate processes leading to the formation of benzene. Thus, regular monitoring and evaluation of strategies, especially in production facilities to control reckless applications of benzoates and also educate producers and consumers would safeguard life.

This research received no specific grant from any funding agency in the public, commercial, private, or not-for-profit sectors.
Authors contribution
Sahadatu L. Azuma wrote the final manuscript; and Naa Kwarley-Aba Quartey contributed significantly in writing the final manuscript. Isaac W. Ofosu, designed the study, worked on the final manuscript and made significant corrections prior to submission.
Declaration of Competing Interest
The authors declare that there is no conflict of interest.

The preservative activity of benzoic acid was described as early as 1875 by H. Fleck and was the first preservant permitted by the FDA. It is used in foods, cosmetics and drug formulations.

Although benzoic acid is found in many plants, it is converted to the active sodium benzoate form to overcome its solubility challenges.

It is an effective preservative in baked products due to its activity against molds responsible for spoilage of most baked products. It is also used to control yeast, pathogenic and spore forming bacteria.2

In aqueous media and pH around 5.0, sodium benzoate transforms to benzoic acid which in the undissociated form can disrupt microorganisms’ cell wall. This retards their growth.  At pH 4.0, 60% of the molecule is in the undissociated form compared to only 1.5% at pH 6.0.2

Despite the potential adverse effect of combining sodium benzoate and vitamin C and formation of benzene, the FDA states that levels of benzene are well below dangerous limits in properly formulated foods.3

Commercial production
Sodium benzoate is commercially produced using the following process1

Neutralization: benzoic acid is mixed in a tank containing sodium hydroxide. The pH  is controlled at 7.5-8.0 and a temperature of 95-98 °C (203-208 °F). The reaction is completed in 30-40 min
Bleaching: removes undesirable colors
Filtering: typically under pressure (0.3-0.4 Mpa) to obtain a clean solution
Drying: it is oven-dried at 150-155 °C (302-311 °F)
Packaging: particulates  of 1.5-2.0 mm are packed in suitable containers
Similar to other preservatives, sodium benzoate can be mixed in the baked good formula or can be dusted onto the surface. Permitted usage levels of in food products are:

Product    Recommended Level    Benefits    Drawbacks
Carbonated beverages    0.02%    Prevents yeast spoilage    In presence of ascorbic acid and metal ions, may produce benzene in ppb concentration
Fruit juices    0.05 – 0.1 %    Protects against mold and fermentation.
Usage with sulfur dioxide or other antioxidants increases antioxidation effect.

Ineffective against oxidation and enzymatic spoilage
Pickles and sauerkraut    0.1%    Highly effective at prevailing low pH    Risk of impairing the flavor
Mayonnaise    0.05 – 0.1%    Imparts a stronger anti-bacterial effect when combined with potassium sorbate.    Risk of impairing product sensory properties
Baked goods    0.1%    At low water activity and pH of 4.5 presents the optimal antimicrobial effect.    At high water activity (>0.8) only limited antimicrobial effect.
White layer cake    0.1%    At pH value 6.4 presents the highest antimicrobial and antifungal effect in comparison with nisin and sulphite.    May slightly decrease cake volume.

FDA regulations
Sodium benzoate is generally recognized as safe by the FDA, when used for its intended purpose.6

“Sodium Benzoate.” National Center for Biotechnology Information. PubChem Compound Database. U.S. National Library of Medicine. Accessed 23 July 2020.
Jay, J M., Loessner,M.J and Golden, D.A . Modern food microbiology.7 th ed., Springer Science & Business Media, 2005.
Food and Drug Administration (FDA). US Department of Health and Human Services. “Chemical Contaminants – Questions and Answers on the Occurrence of Benzene in Soft Drinks and Other Beverages.” Questions and Answers on the Occurrence of Benzene in Soft Drinks and Other Beverages, Center for Food Safety and Applied Nutrition,, Accessed 24 July 2020.
Guynot, M. E., Ramos, A.J., Sanchis, V. and Marín, S. “Study of benzoate, propionate, and sorbate salts as mould spoilage inhibitors on intermediate moisture bakery products of low pH (4.5–5.5).” International Journal of Food Microbiology 101.2 (2005): 161-168.
Adeoye, B . “Comparative Evaluation of the Preservative Effect of Benzoate, Sulphite and Nisin on the Quality of White Layer Cake”. Greener Journal of Science, Engineering and Technological Research. 2. 048-052. 10.15580/GJSETR.2012.3.1212. (2012).
Food and Drug Administration (FDA). US Department of Health and Human Services. CFR Code of Federal Regulations Title 21, Part 184 Direct Food Substances Affirmed As Generally Recognized As Safe,, Accessed 23 July 2020.

Once synthesized, sodium benzoate inhibits the growth of yeast, mold and nasty bacteria that could grow and thrive in acidic conditions. 
When it combines with asorbic acid—a.k.a. vitamin C—if can cause a reaction that produces benzene, which is a component in gasoline. 
Sodium benzoate can also be found in non-edible things such as cosmetics, shampoo, fireworks.

[Code of Federal Regulations]
[Title 21, Volume 3]
[Revised as of April 1, 2020]
[CITE: 21CFR184.1733]


Subpart B - Listing of Specific Substances Affirmed as GRAS

Sec. 184.1733 Sodium benzoate.
(a) Sodium benzoate is the chemical benzoate of soda (C7H5NaO2), produced by the neutralization of benzoic acid with sodium bicarbonate, sodium carbonate, or sodium hydroxide. The salt is not found to occur naturally.

(b) The ingredient meets the specifications of the "Food Chemicals Codex," 3d Ed. (1981), p. 278, which is incorporated by reference. Copies may be obtained from the National Academy Press, 2101 Constitution Ave. NW., Washington, DC 20418, or may be examined at the National Archives and Records Administration (NARA). 
For information on the availability of this material at NARA, call 202-741-6030, or go to:

(c) The ingredient is used as an antimicrobial agent as defined in § 170.3(o)(2) of this chapter, and as a flavoring agent and adjuvant as defined in § 170.3(o)(12) of this chapter.

(d) The ingredient is used in food at levels not to exceed good manufacturing practice. Current usage results in a maximum level of 0.1 percent in food. (The Food and Drug Administration has not determined whether significally different conditions of use would be GRAS.)

(e) Prior sanctions for this ingredient different from the uses established in this section, or different from that set forth in part 181 of this chapter, do not exist or have been waived.

[42 FR 14653, Mar. 15, 1977, as amended at 49 FR 5613, Feb. 14, 1984]

Sodium benzoate has been shown to be an effective inhibitor of the corrosion of mild steel in distilled water, a moderately hard mains‐water and very dilute (e.g. 0·03%) sodium chloride solutions. 
The concentration of benzoate required for inhibition is greater (0·5%) for machined than for emeried surfaces (0·1% in favourable conditions) and for mains water or chloride solutions (1·0 or 1·5%) as compared with distilled water (0·5%).

Movement of the solution, or saturation with oxygen, assists inhibition, but a pH below 6 causes breakdown. 

Comparisons with sodium chromate show that sodium benzoate is less efficient; it is, however, a ‘safe’ inhibitor since it does not lead to intense localized corrosion when the concentration is just below the minimum for protection. 
The following benzoates have also been shown to possess inhibitive properties: potassium, lithium, zinc and magnesium. 
Zinc is partly, and copper and aluminium completely, protected in 0·05% sodium benzoate solution at room temperature.

An unusually high rate of hydrogen gas evolution occurs in dilute sodium chloride solutions containing insufficient sodium benzoate for complete inhibition. 
A tentative explanation is suggested. The detailed mechanism of the protective action of sodium benzoate is not yet established, but electrode‐potential measurements and film‐stripping experiments provide evidence for the view that anodio inhibition produces and maintains a continuous film. 
Electron‐diffraction examination of the stripped film has so far yielded definite evidence of γ‐ferric oxide (or Fe3O4) only.

Sodium benzoate is a food-grade, biodegradable preservative made from the salt of benzoic acid.

Use: This product is Paraben and Formaldehyde Free. It will fight against Yeast, Molds Gram Positive and Gram Negative Bacteria. 
Sodium benzoate can be used in leave-on and rinse-off applications. 
Challenge Test studies have been done on shampoo and creams. 
It is permitted in natural and organic cosmetics

Use: Purox® S has an extremely high purity, which is achieved through the use of Purox® B top quality benzoic acid, produced in the Emerald Kalama Chemical plant in the Netherlands. 
Its low impurity levels give Purox® S an excellent taste and odor profile, making it the right choice for the most demanding end-product requirements. 
In addition to its exceptional purity, Purox® S offers outstanding physical properties for consistently high performance in all your handling, production and packaging processes. 
Thanks to the unique shaping process, Purox® S has almost perfectly round particles with a narrow particle size distribution. 
The result of this tailor-made particle size distribution is an optimal combination of low dust content, high flow and excellent dissolution properties. 
Dust-free processing is achieved by the minimal content of small particles, and optimal dissolution performance by the absence of large particles.

     benzoate of soda
     benzoate, sodium
     benzoic acid sodium salt
     benzoic acid, sodium salt
     benzoic acid, sodium salt (1:1)
     natrium benzoicum
     sodium benzoate FCC
     sodium benzoate N.F.
     sodium benzoate NF FCC 33 solution
     sodium benzoate NF FCC dust free agglomerate
     sodium benzoate NF FCC powder

Sodium Benzoate
Excipient (pharmacologically inactive substance)

Medically reviewed by Last updated on Oct 26, 2020.

What is it?
Sodium benzoate has a chemical formula of C7H5NaO2. Sodium benzoate is an antimicrobial preservative and flavoring agent used in the food industry and a tablet and capsule lubricant used in the pharmaceutical manufacturing industry.

Sodium benzoate is synthesized by combining benzoic acid with sodium hydroxide. Sodium benzoate does not occur naturally, but when it is mixed with water it produces benzoic acid, which can be found naturally in certain fruits such as plums, cranberries and apples. In the food industry, sodium benzoate is used in foods with an acidic pH such as pickles and salad dressings, in carbonated beverages, and in some fruit juice products.

The U.S. Food and Drug Administration (FDA) specifies a maximum level of 0.1 percent of sodium benzoate in food and at this level sodium benzoate is generally recognized as safe by the FDA. Toxicity of any type would not typically occur until a human ate a diet that contained ninety times the amount specified by the FDA. These low levels are most likely used in the pharmaceutical industry, as well.[1][2][3]

When sodium benzoate is combined with vitamin C, as in some soft drinks and other beverages, and exposed to elevated temperatures or light the cancer-causing chemical benzene may form. The Environmental Protection Agency (EPA) maximum benzene level is set at 5 parts per billion (ppb) for drinking water, as a quality standard. In 2005-2007, the FDA sampled various soft drinks and other beverages that contained both single sodium benzoate and combined sodium benzoate and vitamin C and found that the vast majority of these beverages fell below the maximum level. Those products that were above the upper limit have since been reformulated. However, the FDA did not test every beverage on the market.[4] FDA believes that the results of the surveys indicate that the levels of benzene found in soft drinks do not pose a safety concern.

Sodium Benzoate is the sodium salt of benzoic acid. It has the appearance of white or colorless crystalline powder. It is soluble in water and alcohol.

Sodium Benzoate is widely used as a food preservative, but also has common applications in pharmaceuticals, tobacco products, and as an intermediate for certain dyes. It is often favored for its bacteriostatic and fungistatic properties.

odium Benzoate is used as a preservative to prevent food from molding. It helps keep our products shelf-stable for at least two years from the date of purchase and is used in concentrations of less than 0.5% by volume.

While sodium benzoate is considered safe, scientists have shown that negative side effects occur when it's mixed with ascorbic acid (vitamin C). Their studies indicate that it then turns into benzene, a known carcinogen that may cause cancer.

Uses of Sodium Benzoate
Food. In the food industry, sodium benzoate is used to prevent spoilage from harmful bacteria, yeasts, and molds. It also helps maintain freshness in food by helping to slow or prevent changes in color, flavor, PH, and texture.

Other foods that commonly include sodium benzoate include:

Salad dressings
Fruit juices
Snack foods
Drink. Sodium benzoate is used as a preservative in soft drinks to increase the acidity flavor and as a preservative to extend the shelf life.

Sodium benzoate, potassium benzoate, and potassium sorbate are the three common preservatives in Coke's drink. 
Sodium benzoate is used to protect the taste and it's used as an antimicrobial agent. 
Additionally, we can commonly find sodium benzoate in the ingredient lists

 Sodium benzoate is also used to preserve freshness in carbonated soft drinks. However, it’s used less in  popular sodas, Diet Coke, which use potassium benzoate as the main preservative. 

Cosmetics: Like food and drink products, cosmetics also need preservatives to prevent the growth of bacteria. Preservative-free, natural products cannot be stored for a long time. 

Personal care products: Sodium benzoate can be used as an anti-corrosive and preservative in a large variety of personal care products such as:

Hair products
Baby wipes
Toothpaste. To inhibit the growth of microorganisms in toothpaste, producers usually add a certain amount of preservatives. When considering the antimicrobial effect, safety, and price, sodium benzoate is often the better choice compared with other commonly used preservatives in toothpaste. 

Pharmaceuticals. Sodium benzoate can also be used in pharmaceutical products for its antimicrobial properties, such as in the formulation of tablets, capsules, and cough syrup. 

Is Sodium Benzoate Safe?
Sodium benzoate is generally recognized as safe and can be used as an antimicrobial agent and flavoring agent in food with maximum usage of 0.1%. It’s also generally recognized as safe (GRAS) when used as a preservative in feed.

The FDA considers the maximum allowable level for sodium benzoate in drinking water as 5 ppb. Almost all beverage products are under this number and will not pose a threat to our health.

Many customers have concerns about preservatives such as sodium benzoate. It’s commonly thought that sodium benzoate is bad for your health and comes with several side effects.

The Chemistry of Sodium Benzoate
Sodium benzoate is the sodium salt obtained when benzoic acid reacts with sodium hydroxide. This is an acid-base reaction that produces a salt, which is sodium benzoate, and water. The chemical formula is:

C7H6O2 + NaOH = NaC7H5O2 + H2O

In water, the compound dissolves and dissocates into a sodium ion and a benzoic acid ion. In its solid form it is a white, granular or crystalline powder that can be added to food or cosmetics.

Other sodium compounds with similar names are sodium borate or borax and sodium carbonate or soda. They are sometimes confused with sodium benzoate but are completely different chemicals. Borax is a salt of boric acid and contains boron while soda, distinct from baking soda or sodium bicarbonate, is a salt of carbonic acid. Neither is commonly used as a food additive because they are not as safe as sodium benzoate.

Where Is Sodium Benzoate Found?
Sodium benzoate keeps molds and bacteria from growing in food and cosmetics. It is found in many fruit drinks, in salad dressings and oils, and in jams. Cosmetic manufacturers use it in skin creams and other cosmetics to keep them fresh. It is found naturally in fruits such as plums and cranberries and in spices such as cinnamon. Use of the chemical is widespread because it is inexpensive and because small concentrations, typically 0.05 - 0.1 percent, are effective.

In solution, the benzoic acid ion is the active ingredient and acts directly on micro-organisms to limit their activity. When used in certain foods such as acid citrus drinks, the sodium benzoate may react with the other acids such as citric or ascorbic acids to form benzene, a potential carcinogenic compound. Because the levels of sodium benzoate in most foods are so low, the corresponding concentration of benzene will also be below dangerous levels. In general, sodium benzoate is a safe, common, inexpensive and effective food additive with possibly some restrictions for a high consumption of certain acid foods.

Benzoic acid is one of the oldest chemical preservatives used in the food industry. Gabel (1921) was one of the fi rst to demonstrate that benzoic acid was effective against bacteria. Similar results were reported for fungi and yeasts. The principle mechanism responsible for the antimicrobial activity is the uptake of the benzoic acid molecule by diffusion through the bacterial membrane of the un-dissociated form of the acid which is not charged and lipophilic.

Because of the low solubility, benzoic acid is slowly absorbed and because of a higher dissociation constant (pKa = 4.19) benzoic acid is able to exercise a good antimicrobial effect, not only in the acidic gastric environment but also in the more neutral intestinal environment of piglets. The kinetics of dissociation of benzoic acid is given in Table 1. Benzoic acid might also change the permeability of the microbial cell membranes and can also inhibit specifi c enzyme systems within cells. This makes benzoic acid effective against gram negative as well as against gram positive bacteria, as shown in Table 2 and 3.

A comparative study of six organic acids showed that the inhibiting effect of the acids was more pronounced in stomach content than in content of the small intestine and it appears that coliform bacteria, in contrast to lactic acid bacteria, were unable to grow in stomach content at pH 4.5. Benzoic acid had the highest growth inhibitory effects compared to the fi ve other short chain fatty acids (SCFAs).

Less ammonia
Benzoic acid or benzoate does not accumulate in the body. Once the acid is absorbed from the intestines, it will be metabolised in the liver and be transformed into hippuric acid (by reacting with glycine). Hippuric acid is excreted by the kidneys via the urine. As such, more nitrogen from the protein catabolism is excreted as hippuric acid instead of being excreted as urea. This results in an acidifi cation of the urine and the urinary tract and leads to less ammonia being released from the slurry in the manure pit. Indeed, at a lower pH the urease activity, which transforms urea into ammonia, is inhibited: ammonia is mainly formed from urea in the urine, catalysed by the enzyme urease from faeces according to the formula:

CO(NH2)2 + H20 2 NH4 + CO2

The use of benzoic acid in rearing piglets has gained a lot of interest, however, disadvantages of benzoic acid are the low water solubility, the pungent smell and it creates a dusty environment.

Benzoic acid in another form
Sodium benzoate was the fi rst chemical preservative approved for use in foods by the US Food and Drug Administration (FDA). It is a naturally occurring substance and is found in cranberries, prunes, greengage plums, cinnamon, ripe cloves, apples and many more. The product is bacteriostatic and fungi static under acidic conditions. The FDA labels sodium benzoate as GRAS (generally recognised as safe) and it is authorised in the EU as a food additive: Council Directive No 95/2/EC, E No 211, Annex III: Conditionally permitted preservatives and antioxidants.

It has been reported as sweet, salty and bitter. Results have shown that there may be some differences in the palatability of different organic acid-supplemented diets. When allowed to choose, piglets preferred diets supplemented with sodium benzoate.

Although un-dissociated benzoic acid is the most effective antimicrobial agent for preservation purpose, sodium benzoate is widely used, because it is about 200 times more soluble than benzoic acid. Sodium benzoate converts to benzoic acid when it arrives in the acidic environment of the stomach.

Trials from the Animal Science Group at Wageningen University (The Netherlands, 2007) have shown that sodium benzoate outperformed all other essential oils or plant derived additives in a piglet trial challenged with rotavirus and E.coli 0149K91+K88(ETEC). Feed intake was the highest in the benzoate group compared to the negative control, the carvacrol and the butyrate group. As a consequence, body weight gain after ETEC challenge was highest in the benzoate group compared to the negative control, the carvacrol, the butyrate and the allicin groups.

Kemira sodium benzoate
The weaning period of piglets is worldwide frequently associated with infectious diseases and post-weaning diarrhoea (PWD) or post-weaning enteric colibacillosis. Enterotoxigenic Escherichia coli (ETEC) is the most common cause of this disease and antibiotics have been used over decades as growth promoters in animal production as well as a therapeutic agent, but many bacteria are becoming resistant to antibiotics.

Protural is the sodium benzoate registered in the EU by Kemira Oyj as a zootechnical feed additive for piglets. In January 2011 the EFSA gave a scientifi c opinion on the safety and efficacy of Protural and said that sodium benzoate is a natural substance widely occurring in the environment and safe for the animal and the environment. It is not an irritant to skin and eyes and has a limited exposure of the respiratory system.

Protural is highly soluble and converts easily into benzoic acid in the acidic environment of the stomach:

– solubilisation of sodium benzoate:
C6H5COONa C6H5COO-(sol.) + Na+(sol.)

– precipitation of benzoic acid at pH 4:
C6H5COO– + H+ C6H5COOH(precipitation)

In a laboratory trial this precipitated benzoic acid showed to be very fine and dispersible compared to an industrial produced benzoic acid and thus could present a much higher active surface.

A meta-analysis from fi ve piglet trials showed that the addition of Protural at 4 kg/tonne feed results in signifi cant improvements in growth parameters of piglets as shown in Table 4. Daily growth and fi nal weight are significantly higher in weaning piglets, daily feed intake is consistently increased and feed efficiency (FCR) improved. Moreover treated piglets that received Protural in their diets had more consistent faeces than the control group. The number of piglets treated with antibiotics for diarrhoea was lower in the Protural group than in the control group. Mortality, although statistically not significant, was reduced in all trials. It was mentioned that most of mortalities in the control group are due to Streptococcus suis infection. Faecal samples taken from piglets showed that sodium benzoate dietary supplementation reduced the number of total aerobes, total anaerobes, Enterobacteriaceae and Streptococci.

SCFA combinations
No antimicrobial is completely effective against all microorganisms present in the GI-tract of animals. In theory one should be able to combine various antimicrobials having different modes of action to compensate for this deficiency. It should then be possible to achieve a broader spectrum of action or an increased antimicrobial action– the eubiotic effect – by using such a combination, improving animal performances. Indeed, the practice of dietary acidifi cation is one of the most consistent and economical alternatives to antibiotic growth promoters and especially in piglet diets. Over the past two decades various acids and salts have been used for this purpose. Organic acids lower the stomach pH, improving digestion and increasing the barrier function against harmful microbes. The short chain fatty acids (SCFA) have a bactericidal effect in an acidic environment, mostly against gram negative bacteria. Formic acid is the smallest of the SCFAs, but has the highest acidic character and bactericidal effect in feed and animals. It is widely accepted that combinations of organic acids have a broader antimicrobial effect compared to single acids. Contrary to the SCFA, Protural works as well in the more neutral environment throughout the intestinal tract and is effective also against gram-positive pathogens.

Trials at the University of Leuven- Belgium (2004) with growing piglets showed that acid mixtures with sodium benzoate improve overall feed effi ciency and daily growth significantly better than mixtures with benzoic acid or benzoic acid alone. Sodium benzoate mixtures consistently showed an increased feed intake. At Wageningen University, the Netherlands (2008), it was shown in weaned piglets that feeding sodium benzoate increased the external surface area of both jejunum and total small intestine. This effect was associated with increased daily feed intake since the external surface area of the gut showed a positive correlation with daily feed intake, comparing pigs of all dietary groups. The greater gut surface was not associated with any acute pathological symptoms such as absence of mucus, gastric ulcers, local erosions or local haemorrhages. This was also confi rmed in the experimental farm of Kasetsart University in Bangkok, Thailand in 2010. Piglets fed a combination of acids with Protural have shown a signifi cant increase in villous height versus piglets receiving high inclusions of zinc oxide.

Moreover, this mix with Protural significantly increased feed intake and final weight of piglets, replacing zinc oxide. In many countries indeed zinc oxide is prescribed by veterinarians and used at therapeutic dosages (up to 3,000 ppm) to overcome diarrhoea problems, leading to an enormous environmental challenge.

It may be concluded that sodium benzoate has a positive effect on the intestinal morphology in piglets, showing an increased surface area of jejunum which is associated with increased daily feed intake. These are very important observations as small intestinal development is a nutritional strategy to adapt piglets to solid feed during the weaning period. Moreover, trials confi rmed that Protural can control the intestinal microflora, creating a healthy gastrointestinal tract. It can also be concluded that Protural or mixtures with Protural do not show any taste-aversion, on the contrary they consistantly increase daily feed intake, resulting in a signifi cant increased average daily gain. Feed effi ciency is also signifi cantly improved in the period immediate after weaning.

Sodium benzoate, sometimes also called benzoate of soda, is the sodium salt of benzoic acid. It is an aromatic compound denoted by the chemical formula C7H5NaO2 with a molecular weight of 144.11. Sodium benzoate can be made by chemically combining sodium hydroxide with benzoic acid. In its refined form, sodium benzoate is a white, odorless compound that has a sweet, astringent taste, and is soluble in water. Sodium benzoate has antimicrobial characteristics, and is typically used as a preservative in food products.

Chemical And Physical Properties
Sodium benzoate has a density of 1.44 g/cm3. It melts when over 570°F (300°C), and it does not have a boiling point. Sodium benzoate is supplied as a white powder or flake. During use, it is mixed dry in bulk liquids where it promptly dissolves. Approximately 1.75 oz (50 g) will readily dissolve in 3 fl oz (100 ml) of water. In contrast, benzoic acid has a significantly lower water solubility profile. When placed in water, sodium benzoate dissociates to form sodium ions and benzoic acid ions. Benzoic acid is a weak organic acid that contains a carboxyl group, and occurs naturally in some foods, including cranberries, prunes, cinnamon, and cloves. It is also formed by most vertebrates during metabolism.

Sodium benzoate is an antimicrobial active against most yeast and bacterial strains. It works by dissociating in the system and producing benzoic acid. Benzoic acid is highly toxic to microbes, however, it is less effective against molds. Overall, it is more effective as the pH of a system is reduced with the optimal functional range between pH 2.5 to 4.0. The antimicrobial effect is also enhanced by the presence of sodium chloride.

There are three methods for the commercial preparation of sodium benzoate. In one method, naphthalene is oxidized with vanadium pentoxide to give phthalic anhydride. This is decarboxylated to yield benzoic acid. In a second method, toluene is mixed with nitric acid and oxidized to produce benzoic acid. In a third method, benzotrichloride is hydrolyzed and then treated with a mineral acid to give benzoic acid. Benzotrichloride is formed by the reaction of chlorine and toluene. In all cases, the benzoic acid is further refined to produce sodium benzoate. One way this is done is by dissolving the acid in a sodium hydroxide-solution. The resulting chemical reaction produces sodium benzoate and water. The crystals are isolated by evaporating off the water.

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ChemSpider 2D Image | Sodium Benzoate | C7H5NaO2Save3DZoom
Sodium Benzoate
Molecular FormulaC7H5NaO2
Average mass144.103 Da
Monoisotopic mass144.018723 Da
ChemSpider ID10305
Charge - Charge

More details:
Featured data source
The Merck Index Online
antifungal agent

Names and SynonymsDatabase ID(s)
Validated by Experts, Validated by Users, Non-Validated, Removed by Users
208-534-8 [EINECS]
532-32-1 [RN]
Benzoan sodny [Czech]
Benzoate de sodium [French] [ACD/IUPAC Name]
Benzoate, sodium
Benzoic acid sodium salt
Benzoic acid, sodium salt (1:1) [ACD/Index Name]
MFCD00012463 [MDL number]
Natriumbenzoat [German] [ACD/IUPAC Name]
Natriumbenzolcarboxylat [German]
Sodium Benzoate [ACD/IUPAC Name] [JAN] [JP15] [NF] [USAN] [Wiki]
1173022-20-2 [RN]
62790-26-5 [RN]
Benzoesaeure (na-salz) [German]
Benzoic acid sodium
Natrium benzoicum
Sodium [ACD/Index Name] [ACD/IUPAC Name] [Wiki]
sodium and benzoate
Sodium Benzoate NF FCC
Sodium Benzoate USP
Sodium benzoate, 99.5%
Sodium Benzoate-d5
苯甲酸钠 [Chinese]

A fungistatic compound that is widely used as a food preservative. It is conjugated to GLYCINE in the liver and excreted as hippuric acid. As the sodium salt form, 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. Total Positive and Negative Syndrome Scale scores dropped by 21% compared to placebo.

What is Sodium Benzoate?
Sodium benzoate is a salt made of sodium and benzoic acid. It can be found naturally in fruit and spices like apples, cranberries and cinnamon. Despite being naturally occurring, it is usually synthesised in a lab when needed in large quantities for cosmetics. It is also used as a preservative in food and drink.

Sodium benzoate is a popular ingredient in cosmetics, not because of some amazing skin care property but because it works as a preservative. When an active ingredient in a skin care product like a nutrient or vitamin is used to nourish your skin cells, chances are the same nutrients also make good food for microbes in the air which can colonise your product and turn it mouldy. By including sodium benzoate alongside the active ingredient, you can extend the life span of the product and fight off the growth of mould.


How does it work?
Just like animals and plants, the yeast cell that make up mould need sugar to survive. In yeast, the sugar gets processed by the cells to give energy, carbon dioxide and ethanol, the same process used in wine and beer making. Benzoic acid gets taken up into the yeast cells where it messes with the acidity and stops them turning sugar into alcohol. As they can’t make energy, they die and won’t form a mould colony on the product.

It’s possible to be allergic to benzoic acid and if so it can cause severe swelling, itching and difficulty breathing.

It may cause a burning sensation even in those who are not allergic to it.

Benzoic acid can form trace amounts of benzene under certain conditions like UV light exposure, heat and combination with vitamin C. Benzene is a known carcinogen but as benzoic acid should not be in concentrations above 0.5% and only a fraction of this may for benzene, the amount formed is unlikely to be hazardous. Benzoic acid is not thought to accumulate in the body so regular small, safe doses shouldn’t add up into one large, hazardous dose.

Medicine interactions:

Sodium benzoate may interact with corticosteroids, haloperidol, sodium valproate and valoproic acid.


Other Names
Sobenate, antimol, benzoic acid sodium salt, benzoate of soda, natrium benzoicum, carboxybenzene sodium salt


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