Are there sulfites in seltzer water?

January 2, 2026 •

4 min read

According to the FDA, approximately 1 in 100 people are sensitive to sulfites, with reactions that can range from mild to severe. For those with sensitivity, understanding the ingredients in beverages like seltzer water is crucial. The question of whether this popular fizzy drink contains sulfites is a common one, and the answer lies in its simple composition.

Quick Summary

Pure seltzer water, made only from water and carbon dioxide, does not contain added sulfites, which are chemical preservatives. The presence of sulfites is a concern for sulfite-sensitive individuals, but it's typically found in other beverages like wine, juices, and some processed or flavored sparkling drinks.

Key Points

Seltzer is Sulfite-Free: Pure, unflavored seltzer water is simply water infused with carbon dioxide and does not contain added sulfites.
Sparkling Mineral Water Differs: Unlike seltzer, sparkling mineral water from natural springs may contain naturally occurring sulfur compounds; check the label.
Additives are the Key: Sulfites are typically found in flavored or sweetened beverages, wines, and processed foods, not in pure seltzer.
Label Reading is Crucial: Always read ingredient labels for terms like 'sulfites' or additive codes (E220-E228) to ensure the product is sulfite-free.
Sulfite Sensitivity Varies: For people with sulfite sensitivity, reactions can range from mild asthma-like symptoms to hives; it is not typically an issue for most.
Club Soda is Not Seltzer: Club soda contains added minerals, unlike seltzer, and while it rarely contains sulfites, it's a different product.

The Core Difference: Seltzer vs. Other Carbonated Waters

Understanding the distinction between different types of carbonated water is the key to knowing whether your drink is likely to contain sulfites. While some terms are used interchangeably, they are not all the same, and their mineral or additive content is a primary differentiator.

Seltzer Water: This is the simplest form of carbonated water. It consists of plain water that has been artificially carbonated by infusing it with carbon dioxide (CO2) gas under pressure. Pure seltzer water does not contain any added minerals or sulfites.
Sparkling Mineral Water: This type of water comes from a natural spring or well and is naturally carbonated from underground gas. The mineral content varies depending on the source and can include minerals like magnesium, calcium, and even naturally occurring sulfur compounds. It is important to check the specific brand's label to see its composition.
Club Soda: Similar to seltzer, club soda is artificially carbonated but typically has added mineral salts, such as sodium bicarbonate, sodium citrate, or potassium sulfate, to create a slightly different, more savory taste. The inclusion of mineral salts makes it different from plain seltzer.
Tonic Water: Distinct from the others, tonic water is a carbonated beverage that contains added quinine, which gives it a bitter flavor. It also typically contains added sweeteners, which make it a less healthy option than plain seltzer.

What are Sulfites and Why are They Used?

Sulfites are chemical compounds that are widely used as preservatives and antioxidants in a variety of foods and beverages. They work by inhibiting the growth of microorganisms and preventing browning and spoilage.

Preservative and Antioxidant: They help maintain the freshness and color of dried fruits, canned goods, and condiments.
Stabilizer: In wine and beer, sulfites are added to stabilize the product, prevent undesirable fermentation, and protect against oxidation.
Flavor Enhancer: In some cases, they are used to enhance or preserve the flavor of certain products.

Comparison of Carbonated Water Types


Feature	Seltzer Water	Sparkling Mineral Water	Club Soda	Tonic Water
Composition	Water + Artificial CO2	Water from mineral spring + Natural or added CO2	Water + Artificial CO2 + Added Mineral Salts	Water + Artificial CO2 + Quinine + Sweeteners
Sulfite Content	Generally sulfite-free	Can contain naturally occurring sulfur compounds, but added sulfites are not typical. Check the label.	Added sulfites are not common, but always check the ingredients list.	Unlikely to have added sulfites, but check the label.
Taste Profile	Clean, neutral taste	Distinctive mineral taste, varies by source	Slightly salty, mineral-enhanced taste	Bitter and sweet
Best For...	Hydration, mixing with juices or other pure flavorings	Enjoying on its own for a mineral-rich taste	Mixing cocktails where the salty flavor is desired	Cocktails like gin and tonics

How to Check for Sulfites in Your Beverage

For those with sulfite sensitivity, reading the label is the most reliable method for avoiding them. Regulatory bodies, such as the Food Standards Australia New Zealand, require that added sulfites be declared on the label when present in concentrations of 10 mg/kg or more. Manufacturers must list the class name (e.g., preservative) followed by the specific name (e.g., sulfur dioxide) or code number (e.g., 220–228).

What to look for on a label:

Ingredient List: Scan the ingredient list for terms like sulfites, sulfur dioxide, sodium bisulfite, potassium metabisulfite, or other sulfite-based codes (E220-E228).
Allergen Statements: Many products will have a separate section stating "Contains Sulfites" as they are a priority allergen for many.
Type of Beverage: Be cautious with flavored seltzers, as added flavorings, juices, or sweeteners could be sources of sulfites. Always check the label, even if the base is seltzer.

The Health Implications of Sulfites

For the vast majority of the population, sulfites are a non-issue. However, for sulfite-sensitive individuals, consumption can trigger a range of adverse reactions.

Common Symptoms: These can include wheezing, chest tightness, coughing, shortness of breath, hives, and stomach pain.
Severe Reactions: In rare cases, a severe allergic reaction known as anaphylaxis can occur, though it is not a common outcome.
Asthma: People with asthma are particularly susceptible to sulfite sensitivity, and for some, it can trigger an asthma attack.

For those concerned about these symptoms, it is always recommended to consult a healthcare professional. You can find more authoritative information on sulfite sensitivity from medical resources like the Cleveland Clinic.

Conclusion: The Bottom Line on Seltzer and Sulfites

Plain, unflavored seltzer water is a safe choice for those looking to avoid added sulfites, as it contains only carbonated water and no other additives. The risk for sulfite exposure is significantly higher in other carbonated beverages, such as some flavored sparkling waters, club sodas with added mineral salts, and tonic water. For individuals with sulfite sensitivities, the best course of action is to always check the ingredient label of any sparkling beverage to ensure it does not contain any added sulfites or other potentially reactive ingredients. When in doubt, a simple bottle of pure seltzer provides a bubbly, refreshing, and sulfite-free option.

Frequently Asked Questions

Yes, there is a difference. Plain seltzer is artificially carbonated water with no added minerals, and thus no added sulfites. Sparkling mineral water, however, comes from a spring and may contain naturally occurring sulfur compounds, so it's important to check the label for specific ingredients.

You should look for the word "sulfites" in the ingredients list or for specific names like "sulfur dioxide," "sodium bisulfite," or "potassium metabisulfite." Also, be aware of additive codes from E220 to E228, which denote various sulfite compounds.

Not necessarily. While pure seltzer is sulfite-free, flavored seltzers or seltzer beverages with added fruit juices or other ingredients could contain sulfites. It is crucial to check the ingredient label of any flavored product.

Sulfites are commonly added to act as a preservative, preventing spoilage, and as an antioxidant, which helps maintain color and freshness. They are frequently found in dried fruits, wines, and some bottled fruit juices.

Symptoms of sulfite sensitivity can include wheezing, chest tightness, coughing, hives, and stomach pain. The severity can vary greatly, and reactions are more common in individuals with asthma.

Tap water can contain naturally occurring sulfates, which are different from added sulfites. High concentrations of sulfates can affect taste but are generally not a health hazard. Seltzer is only infused with CO2, so the risk is minimal unless other additives are used.

To be completely certain, choose a plain, unflavored seltzer and check the ingredient label to confirm it only lists water and carbon dioxide. Many popular brands pride themselves on their minimal, pure ingredients.