What is Sodium Bisulfite E222? Property, Uses, Safe, Side Effects

What is Sodium Bisulfite E222? Property, Uses, Safe, Side Effects

What is sodium bisulfite

Table of Contents

Sodium Bisulfite, also commonly known as E222 and Hydrogen Disulfide, can be used as a preservative in food and other food ingredients, as well as in the cosmetic formulation and dental care products. It is one of the most widely used food additives in the world with an annual consumption exceeding 1 million tons. In this article learn about Sodium Bisulfite E222, the chemical formula, white crystals, uses, and the applications of sodium bisulfite food additives.

What is sodium bisulfite?

Sodium bisulfite is a chemical compound with the formula NaHSO3. It is the sodium salt of bisulfite, an inorganic sulfiting agent. Sodium bisulfite is white, soluble in water, and has a neutral pH.

Sodium bisulfite is used as a food additive in the form of its sodium salt to preserve color in potatoes, onions, and other vegetables. It is also used to bleach foods such as shrimp paste, which would otherwise turn grayish-green when cooked. Sodium bisulfite is used as a preservative for dried fruit and also as a bleaching agent for wine and beer.

Sodium bisulfite is sometimes added to canned foods (e.g., soups) to inhibit bacterial growth. It may be found in antibacterial soap products as well at concentrations up to 0.1%. The US FDA allows its use at concentrations from 0–0.5% by weight in antibacterial soap products marketed without prescription status; however, it cannot be used in antibacterial mouthwash products because it can cause allergic reactions such as asthma attacks or hives.

What is sodium bisulfite used for?

Sodium bisulfite is a chemical compound that’s used as a food additive. It is also used as a preservative in the wine industry, and in other industries as well.

In the wine industry, sodium bisulfite helps prevent oxidation and bacterial contamination in wines. It also has preservative properties that help keep other foods safe from spoilage.

Sodium bisulfite is used to preserve fruits and vegetables that are packaged for long-term storage or shipment. This compound can be used to keep potatoes from sprouting, for example. It’s also used in canned fruits to prevent discoloration and browning of the fruit’s skin before it’s cooked into jams or pies.

Sodium bisulfite is used in the manufacturing of paper, textiles, leather goods, detergents, and cosmetics. It is also used in the bleaching of pulp for paper making. Sodium bisulfite helps to maintain the color of the bleached pulp as well as serves as an antioxidant in this process.

Sodium bisulfite is also found in many common household products such as toothpaste, mouthwash, and antibacterial soaps. It is also used as an antimicrobial agent in many foods including baked goods, soft drinks, and jams.

Sodium bisulfite is a chemical additive that has many uses in the food industry. It’s often used in preserving, pickling, and canning foods to prevent discoloration and bacterial growth. Sodium bisulfite may also be added to fresh fruits and vegetables to help control their ripening process.

Sodium bisulfite is also used as an antioxidant in beer brewing, winemaking, and coffee roasting processes to prevent browning or fading of color. It’s also added to cosmetics for its bleaching properties. When combined with hydrogen peroxide, sodium bisulfite forms sodium persulfate, a chemical used by dentists to sterilize instruments before use in root canals or other dental procedures.

In addition to its uses in food processing, sodium bisulfite has other industrial applications as well. It’s used as a preservative in papermaking processes and as an ingredient in hair dyes and toilet bowl cleaners among other household products

How is sodium bisulfite made?

Sodium bisulfite is produced by passing gaseous hydrogen sulfide through hot soda ash, or by reacting sodium carbonate with sulfur dioxide at high temperature (950–1000 °C). It was first prepared in 1837 by the French chemist Nicolas Clément by passing hydrogen sulfide through molten sodium carbonate:

Na2CO3 + H2S → NaHSO3 + CO2

It can also be obtained by passing hydrogen sulfide into a solution containing the potassium salt of sulfurous acid:

KHSO4 + H2S → KHSO4·H2SO4 + H2O

Its solution in water gives rise to an intense violet coloration due to the formation of bisulfite ion and hydrosulfite ion [HSO3(OH)−].

Other names Sodium bisulphite, Sodium hydrogen sulphite, Sodium acid bisulfite
CAS number 7631-90-5
Chemical formula NaHSO3
Molecular weight 104.06
Boiling point 315°C
Melting point 150°C


  • Solid: white granules or powder with a sulfur dioxide odor.
  • Liquid: Clear, colorless to yellow solution.


Water-soluble, slightly soluble in ethanol. The main form of SO2 dissolved in water is NaHSO3. It is important to take into account the equilibrium between the inorganic forms of sulfur dioxide (sulfur dioxide, bisulfite, and sulfite ions).

As it heats or reacts with acids, sulfur dioxide gas is released.

The aqueous solution is acidic with PH 2.5-5.5 (10% aqueous solution) when dissolved in water. Bisulfite (HSO3*) is dissociated.

Following the dissolution of NaHSO3 in water, the following equilibrium exists:

HSO3- H+ + SO32-

HSO3- + H2O H2SO3 + OH

H2SO3 SO2 + H2O



What’s the application of sodium bisulfite?


In general, sodium bisulfite in food can serve as an antimicrobial and antioxidant agent. As a preservative, sulfur dioxide gas is released when the compound is added to water under acidic conditions.

Furthermore, it can be used as an oxygen scavenger to prevent food spoilage due to oxidation by reacting with oxygen first. This protects the color (anti-browning), freshness, and flavor of food.

Fruits and vegetables

Typically, NaHSO3 is used to preserve fruits and vegetables by preventing the enzymatic browning caused by polyphenol oxidase. It is commonly used in the canning of fruits and vegetables, especially leafy greens.


When shrimp are exposed to oxygen, sodium bisulfite is often applied to prevent or slow down the development of black spots (melanosis). As a result, sodium bisulfite maintains shrimp’s appearance.


In high-temperature processed cheese manufacturing, it prevents browning caused by the Maillard reaction.

Corn starch

In addition to softening corn kernels, sodium bisulfite reduces the mechanical strength of corn, allowing starch and fiber to be easily separated.

The salt is more stable in aqueous solutions than sulfurous acid.


Various ingredients in some drugs are prone to oxidation, so this substance is used as an antioxidant to prevent them from oxidizing.


Using it in agriculture can increase the rate of photosynthesis and increase the amount of fruit produced.

Sodium bisulfite can increase chlorophyll content in fruit by reducing sulfur to sulfhydryl (-SH), accelerate photosynthetic rate by inhibiting glycolate oxidase and reducing carbon dioxide release, and promote the accumulation of photosynthetic products in fruit.


In addition to bleaching cotton fabrics, sodium bisulfite is used as a reducing agent in dye, paper, leather, and other chemical synthesis.

Water treatment

NaHSO3 is a mild reducing agent that can be used to chlorinate wastewater. In wastewater, it is used to remove residual chlorine after adequate contact time with chlorine has been provided for disinfection.

Hypochlorous acid reacts in the following way:

2NaHSO3 + 2HOCl => H2SO4 + 2HCl + Na2SO4

You can also use it to remove bromine and iodine from water.

Is sodium bisulfite safe?

Sodium bisulfite is a chemical that’s used as a food additive. It’s also used to preserve wine and prevent discoloration and browning in foods such as fruit juices and dried fruits.

The FDA has set limits on how much sodium bisulfite is safe to consume. These limits are based on the amount of sodium bisulfite that can be eaten in a day without any negative health effects.

As far as side effects are concerned, it almost has none, and its safety has been approved by the FDA, EFSA, and the Joint FAO/WHO Expert.


According to the FDA, it’s safe for adults to eat up to 15 milligrams of sodium bisulfite per kilogram (mg/kg) of body weight each day. This means that an average adult (70 kg) can safely consume up to 1,050 mg of sodium bisulfite per day without any adverse effects.


In Regulation (EU) No 231/2012, sodium bisulfite (E222) is listed as an authorized food additive under the category “Additives other than colors and sweeteners”.

Safety re-evaluation in 2016

On the basis of available genotoxicity data, EFSA concluded that sodium bisulfite is not a genotoxic food additive, and established a temporary ADI of 0.7 mg as SO2 equivalent/kg bw per day for E220 and E228, respectively.

Approved uses

It is listed in the food application data sheet along with other sulfites (sulfur dioxide (E220), sodium sulfite (E221), sodium bisulfite (E222), potassium metabisulfite (E224), calcium sulfite (E226), calcium bisulfite (E227) and potassium bisulfite (E228) maximum dosage levels are between 10 and 2000 mg/kg.

UK Food Standards Agency

In the “Preservatives” category

Food Standards Australia New Zealand

In Australia and New Zealand, it is approved as an ingredient under the code number 222.


Classification: food additive, antioxidant, preservative.
In 1998, the ADI was set as “0-0.7 mg/kg bw” expressed as sulfur dioxide.

The pH of sodium bisulfate is between 4 and 5. It is a colorless, crystalline solid with a chemical formula NaHSO4. It is also called sodium sulfate heptahydrate or sodium bisulfate decahydrate.

A substance’s pH value indicates how acidic or basic it is. The lower the pH value, the more acidic the substance is; the higher the pH value, the more alkaline it is. The neutral range is 7, while anything below 7 is acidic, and above 7 is basic.

How to use sodium bisulfate to lower pH?

If you need to lower the pH of your pool water, there are several ways to do it. The easiest way is to use sodium bisulfate or sodium bisulfite as an algaecide and shock treatment for pools. The active ingredient in these products is sodium bisulfate, which lowers the pH of your pool water when added directly to it.

The amount of sodium bisulfate needed depends on how much chlorine you normally use and how much alkalinity there is in your water. You should add about 1 ounce per 10,000 gallons of water (1 ppm) if you’re using liquid chlorine bleach or trichloro-s-triazinetrione (shock treatment).

Sodium metabisulfite vs sodium bisulfite

Sodium metabisulfite and sodium bisulfite are two types of sulfites that can be used in food processing. Both are used as preservatives and antioxidants in foods, but they differ in their chemical structure and purpose. Sodium metabisulfite is an additive in wine and beer making, while sodium bisulfite is often used in canning fruits and vegetables to preserve their color.

Sodium Metabisulfite vs Sodium Bisulfite: What’s the Difference?

The chemical formula for sodium metabisulfite is Na2SO3; it has a molecular mass of 138.04 g/mol, or the equivalent of 108 grams per mole. It’s also known by its name potassium hydrogen sulfite, which means that hydrogen sulfide (H2S) is attached to potassium (K). This combination allows it to be easily dissolved in water. The chemical formula for sodium bisulfite is NaHSO3; it has a molecular mass of 151.99 g/mol, or the equivalent of 106 grams per mole.

Sodium metabisulfite is a chemical compound that has the chemical formula Na2S2O5. It is commonly used in the wine industry as a preservative. Sodium metabisulfite also acts as an antioxidant, which can help preserve the color of wine. This chemical is also used in other industries such as photography and textile manufacturing.

The compound NaHSO3 (sodium bisulfite) is another type of chemical that you may find in your local grocery store or pharmacy. This compound has many uses including preserving food and cleaning swimming pools. Sodium bisulfite has been used for centuries to protect foods from spoilage. Some people use this chemical to make pickles or sauerkraut because it inhibits the growth of bacteria in these foods while still allowing them to ferment naturally over time.

Sodium bisulfite vs sodium bisulfate

Sodium bisulfite and sodium bisulfate are both chemical compounds that contain sodium, sulfur and oxygen. They are both salts, which means they have a charge due to the presence of an ion. The difference between the two compounds is the number of oxygen atoms present in each molecule.

Sodium bisulfite contains one oxygen atom per molecule and can be made by mixing sodium hydroxide with sulfur dioxide gas. Sodium bisulfate contains two oxygen atoms per molecule and can be made by mixing sodium hydroxide with sulfuric acid or hydrogen sulfide gas. These two compounds are synthesized in different ways, but they share many similarities.

Both compounds have strong odors, although some people report that they can smell the difference between them based on their odor alone. They also exhibit similar solubility characteristics: both dissolve best in acidic solutions, although each dissolves slightly better in its own respective solvent (sodium bisulfite dissolves better in water than sodium bisulfate). Both chemicals can be used as preservatives for food products as well as cleaning agents for water treatment systems, leather tanning processes, and photographic developers.

What is sodium bisulfite used for in water treatment?

Sodium bisulfite is used in the water treatment industry as a disinfectant and algicide. It is used in pools, spas, hot tubs, fountains, water parks, and other recreational water facilities.

Sodium Bisulfite is added to the water at the point of entry or after filtration if it is used as a post-treatment agent. The bisulfite reacts with chlorine and other chloramines to form hydrogen sulfide gas which is then released into the atmosphere. This process reduces the concentration of chloramines thereby reducing their potential for irritation to bathers’ eyes and respiratory system.

Sodium bisulfite also acts as a corrosion inhibitor for metals such as copper and brass commonly found in pool equipment such as heat exchangers and piping systems that come into contact with potable water. It helps to prevent pitting from occurring on these metal surfaces due to their exposure to chloramines that typically exist at higher concentrations in swimming pools than other sources of chlorinated water such as tap water or even municipal drinking water supplies.

How to do the sodium bisulfite test?

The sodium bisulfite test is a chemistry test that can be used to determine whether or not a substance contains sulfur. This test is particularly useful for identifying the presence of sulfur in urine, as well as in other bodily fluids.

Sodium bisulfite is also known as sodium metabisulfite and sodium pyrosulfite. It is an inorganic chemical that contains sodium and sulfur, along with a few other elements. This compound forms bright yellow crystals when it’s dry and powdery when it’s wet. Sodium bisulfite is used in photography, food processing, water treatment, and many other applications because it prevents spoilage and helps preserve color during chemical reactions.

How to Do the Sodium Bisulfite Test

You’ll need:

-A clean container (a glass jar) large enough to hold your urine sample

-Some distilled water (distilled water has fewer contaminants than tap water)

-A dropper (or pipette) so you can drop small amounts of liquid into the jar without spilling them all over the place

– Put a few drops of distilled water into the jar. The number of drops depends on how much urine you have. If you have a small amount, one or two drops is enough. For larger samples, add more drops until the jar is almost full.

– Add your urine sample to the distilled water. Make sure that it doesn’t touch any other part of the jar except for the bottom. If it does, carefully pour out some of your samples until it doesn’t touch anything else in there anymore.

What’re the side effects of sodium bisulfite?

Sodium Bisulfite is a chemical used in the bleaching and preservation of wood. It is also used in the vulcanization of rubber, to soften leather, and as a photographic fixer.

Sodium bisulfite may cause some side effects if it is not properly handled or if it is taken in high doses. The following are some of the most common side effects of sodium bisulfite:

  • Sodium bisulfite may cause mild skin and eye irritation. It is toxic if swallowed or inhaled.
  • Sodium Bisulfite may cause irritation if it comes into contact with your eyes, mouth or skin. If this happens, wash it off immediately with plenty of water for at least 15 minutes. If irritation continues after washing, seek medical attention.
  • Sodium Bisulfite is not considered to be toxic when swallowed or inhaled. However, it may cause nausea and vomiting if ingested in large amounts. Inhalation of large amounts may result in respiratory tract irritation and pulmonary edema (fluid build-up in the lung).

Where to buy sodium bisulfite?

If you are looking for sodium bisulfite, you can find it in a number of places. One of the most common places to buy sodium bisulfite is from your local pool supply store. This is because many people use it to keep their pools clean and clear. You can also find it in some grocery stores or even online, Such as on amazon and eBay.

if you purchase a large quantity for your company, you can consider purchasing from Grade Chemical.  For Grade Chemical is one reliable sodium bisulfite supplier in China. they can directly deliver to you by courier. for the price is much more competitive than the local store price.

Frequently asked questions

Sodium bisulfite has been approved by the FDA as an indirect food additive, which means that in order for it to be added to any food product, it must be used in a process that occurs before the food is packaged. This allows the food companies to use sodium bisulfite without having to get approval from the FDA each time they want to use it.

Is sodium bisulfite an acid or a base?

Sodium bisulfite is a weak acid, with a pH of about 5.0. It can be used as an antifungal agent and as a preservative for food, but it’s not often used in the home because it can cause allergic reactions in some people.

Is sodium bisulfite gluten free?

Yes, sodium bisulfite is gluten-free. Sodium bisulfite is a compound that is used as a preservative and antioxidant in food and beverages, and it is also used to bleach paper products.

Is sodium bisulfite vegan?

Yes, the raw materials and manufacturing process do not contain any animal matter or products of animal origin.


Though some people may be sensitive to it, the question of whether or not E222 has any significant side effects does not appear to have been answered definitively. In rare cases, allergic reactions to sulfites have led to severe breathing problems; if you notice such symptoms after consuming food that contains E222, seek immediate medical attention. Aside from these rare instances, however, it appears that this preservative can safely be used in food products.

If you want to buy high-quality Sodium Bisulfite E222 online, don’t hesitate, we are your best choice. As one of the most professional Sodium Bisulfite E222 manufacturers in China, we have years experience of in Sodium Bisulfite E222 production. Please be free to get high-quality products from our factory.

Sophie Feng

Sophie Feng

Sophie Feng is the author of gradechemical.com, she is the co-founder of the grade chemical network. She has been in grade chemical company since 2017, with a working knowledge of food chemical .

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