Is Sodium Metabisulfite in Food Bad for You? Separating Fact from Fear

January 5, 2026 •

3 min read

According to the Cleveland Clinic, sulfites—including sodium metabisulfite—can cause respiratory symptoms in up to 5% of people with asthma. While most people can consume this preservative without issue, certain sensitive individuals need to be aware of its presence in food.

Quick Summary

Sodium metabisulfite is a common food preservative and antioxidant generally safe for most consumers within regulatory limits. However, sensitive individuals, especially those with asthma, can experience adverse reactions, including allergic symptoms and respiratory issues.

Key Points

Generally Safe for Most: For the majority of consumers, sodium metabisulfite is safe when consumed within regulated food additive limits.
High Risk for Asthmatics: Individuals with asthma are particularly susceptible to sulfite sensitivity, which can trigger respiratory issues like wheezing and chest tightness.
Allergic Reactions Can Occur: Though not a true allergy, sulfite sensitivity can cause allergic-like symptoms, including hives, stomach upset, and, in rare cases, anaphylaxis.
Common in Processed Foods: This preservative is widely used in wine, dried fruits, canned vegetables, and other processed items, making label-reading essential for sensitive individuals.
Natural and Chemical Alternatives Exist: For consumers and manufacturers concerned about sulfites, alternatives such as ascorbic acid, natural preservatives, and enzymes are available.

What is Sodium Metabisulfite?

Sodium metabisulfite (Na₂S₂O₅), also known as E223, is a synthetic chemical used in food as a preservative and antioxidant. It's a white powder that releases sulfur dioxide gas when mixed with water, which provides its functional properties.

Functions in Food Production

Manufacturers use sodium metabisulfite to enhance food quality and increase shelf life. Its primary roles include inhibiting microbial growth (bacteria, mold, yeast), acting as an antioxidant to prevent spoilage and maintain appearance, and preventing enzymatic browning in items like dried fruits and pre-cut vegetables. It can also condition dough in baking and is used as a bleaching agent.

Potential Health Risks and Side Effects

Most people consume regulated amounts of sodium metabisulfite without harm, but some individuals may experience adverse reactions.

Sulfite Sensitivity and Allergies

The main concern is sulfite sensitivity, particularly common among people with asthma. Reactions, while not true allergies, can cause symptoms such as wheezing, chest tightness, shortness of breath, hives, rashes, nausea, and abdominal pain. Severe anaphylactic reactions are very rare.

Other Reported Effects

Animal studies with high doses suggest potential links to increased oxidative stress and neurotoxicity, but these findings may not apply to typical human exposure through food. Concentrated forms are hazardous for industrial handling but not generally a consumer concern.

Who is at Risk for Sulfite Sensitivity?

Asthmatics: Up to 13% of individuals with asthma may be sensitive to sulfites.
Sulfite Oxidase Deficiency: A rare genetic condition affecting the body's ability to process sulfites.
Children: Sulfites are banned in infant foods partly due to infants' less developed detoxification systems.

Foods That May Contain Sodium Metabisulfite

Sulfite-sensitive individuals should check food labels as sodium metabisulfite and other sulfites are present in many products.

Common examples include:

Wine and beer
Dried fruits
Processed potato products
Bottled lemon and lime juice
Canned and frozen vegetables
Certain baked goods
Processed meats like sausages
Condiments and sauces
Dried herbs and spices
Coconut milk and glaced fruits

Comparison Table: Sodium vs. Potassium Metabisulfite


Feature	Sodium Metabisulfite (Na₂S₂O₅)	Potassium Metabisulfite (K₂S₂O₅)
Cost	Generally less expensive	Generally more expensive
Sulfite Potency	Slightly higher concentration of sulfur dioxide	Lower concentration of sulfur dioxide
Effectiveness	Highly effective as a preservative and antioxidant	Also highly effective; preferred for wine aging
Side-Effects	May cause stronger adverse reactions in sensitive individuals due to higher SO₂ content	Lower sulfite release can make it a better option for sensitive individuals
Sodium Content	Introduces trace amounts of sodium	Contains potassium instead of sodium
Taste Impact	Can impart a subtle salty or metallic taste if overused	Less likely to impart off-flavors, especially in wine

Alternatives to Sodium Metabisulfite

Several alternatives are used by manufacturers to preserve food without sodium metabisulfite:

Potassium Metabisulfite: Often used in winemaking; has lower sulfite load and no sodium.
Natural Preservatives: Salt, sugar, and vinegar can provide preservation but may not match the shelf life.
Ascorbic Acid (Vitamin C): A natural antioxidant used to prevent spoilage and browning.
Enzymes: Proteolytic enzymes can be used in baking to condition dough.
Hydrogen Peroxide: An odorless option for equipment sterilization.

Conclusion

In conclusion, sodium metabisulfite is safe for most people at approved levels and plays a valuable role in food preservation. However, it poses a significant risk to those with sulfite sensitivity, particularly asthmatics. Label reading is vital for susceptible individuals. Alternatives exist, and labeling is mandated to aid informed choices. For more details on sulfite reactions, consult the National Institutes of Health review: Adverse reactions to the sulphite additives - PMC.

Frequently Asked Questions

Sodium metabisulfite is a chemical food additive (E223) used primarily as a preservative and antioxidant. It prevents microbial growth and oxidative spoilage, which extends the shelf life and maintains the appearance of many food products.

Yes, regulatory bodies like the FDA have banned its use in certain foods, such as fresh fruits and vegetables, due to past reactions. It is also prohibited in infant foods due to the potential risk to infants' less developed digestive systems.

Food products containing sulfites, including sodium metabisulfite, are required by law to be clearly labeled. The ingredient may be listed by name or as a general sulfite, so it's important to read labels carefully.

Yes, some foods naturally contain sulfites in trace amounts. Examples include fermented foods, maple syrup, and certain types of eggs, although added sulfites are typically found in higher concentrations.

Symptoms can range from mild to severe and may include wheezing, chest tightness, hives, flushing, stomach pain, diarrhea, and, in rare instances, anaphylactic shock.

No, sulfites are stable compounds and are not effectively removed by cooking or heating. The released sulfur dioxide may dissipate, but the sulfite residue remains.

Both are sulfite preservatives, but potassium metabisulfite is a potassium salt, while sodium metabisulfite is a sodium salt. Potassium metabisulfite releases slightly less sulfur dioxide and is often preferred in winemaking to avoid adding sodium.