Is It Safe to Eat Fruit Treated with Sulfur Dioxide?

December 19, 2025 •

3 min read

According to the U.S. Department of Agriculture (USDA), sulfur dioxide is a long-standing food preservative used to prevent discoloration and microbial growth in foods like dried fruit. The key question many consumers have is: is it safe to eat fruit treated with sulfur dioxide? While generally safe for most, it can pose a serious health risk to a small percentage of the population.

Quick Summary

Sulfur dioxide is a common preservative in dried fruits, deemed safe for the majority of people. However, individuals with asthma or a sulfite sensitivity may experience adverse reactions. Understanding food labels and identifying alternatives is key to safe consumption.

Key Points

Generally Safe for Most: At legally approved levels, sulfur dioxide in dried fruit poses no health risk to the majority of people.
Risky for Asthmatics: Individuals with asthma or sulfite sensitivity can experience allergic-like symptoms, including wheezing and shortness of breath.
Labeling is Required: By law, foods containing more than 10 ppm of sulfites must be clearly declared on the ingredient list.
Sulfite-Free Alternatives Exist: Organic and natural dried fruits are processed without sulfur dioxide and are safe for sensitive consumers.
Sulfites Can Be Reduced: Soaking dried fruit in water can help lower residual sulfite levels, but it may not remove them completely.
Benefits of Use: Sulfur dioxide acts as a preservative, preventing microbial spoilage and preserving the fruit's color.

Understanding Sulfur Dioxide in Your Food

Sulfur dioxide ($SO_2$) is a colorless gas with a pungent odor that has been used for centuries as a food preservative and antioxidant. In the food industry, it is used on a variety of products, but it is most prominently associated with dried fruits, wine, and processed vegetables. Its primary functions are to prevent enzymatic and non-enzymatic browning, which maintains the fruit's bright color, and to inhibit the growth of spoilage microorganisms like bacteria and yeast, thereby extending shelf life. Without this treatment, light-colored dried fruits like apricots and golden raisins would quickly turn dark brown and spoil more rapidly.

The Health Effects of Sulfur Dioxide

For the vast majority of the population, consuming fruit treated with sulfur dioxide at legally permitted levels is not a health concern. The human body can typically metabolize and excrete sulfites, the compounds formed from sulfur dioxide. However, a significant concern exists for susceptible individuals, particularly those with asthma. The U.S. Food and Drug Administration (FDA) banned the use of sulfites on fresh produce in 1986 due to adverse reactions in asthmatics, but it remains approved for other food products, including dried fruit.

Potential adverse reactions for sulfite-sensitive individuals include:

Respiratory symptoms: Wheezing, shortness of breath, and chest tightness.
Skin reactions: Hives, rashes, and swelling.
Gastrointestinal issues: Nausea, stomach pain, and diarrhea.
Other symptoms: Headaches and nasal congestion.
Anaphylaxis: In rare but serious cases, life-threatening anaphylactic shock can occur.

Legal Regulations and Labeling

To protect consumers, food safety regulations around the world mandate the labeling of sulfites. In many regions, including the U.S. and the EU, if a product contains 10 parts per million (ppm) or more of sulfites, it must be declared on the label. This helps sensitive individuals avoid foods that could trigger a reaction. Common ingredient names for sulfites include sulfur dioxide, sodium sulfite, sodium bisulfite, and sodium metabisulfite. Consumers should always check the ingredient list, especially on processed foods with a long shelf life.

Can You Remove Sulfur Dioxide from Dried Fruit?

Some studies have explored methods for reducing the sulfite content in dried fruits. Soaking dried fruit in water, particularly hot water, or in a dilute solution of organic acids like citric acid can help reduce the residual sulfur dioxide levels. For example, research has shown that soaking raisins in warm water can significantly decrease their $SO_2$ concentration. However, this process is not guaranteed to remove all sulfites, and it may also affect the fruit's texture and flavor.

Alternatives and Safe Consumption Practices

For those with a sulfite sensitivity, or who prefer to avoid food additives, several alternatives are available. Organic dried fruits are a reliable option, as certified organic products generally prohibit the use of synthetic preservatives like sulfur dioxide. These sulfite-free fruits often have a naturally darker, browner color and a more intense, sometimes slightly caramelized flavor. To prolong their freshness without chemical preservatives, they can be stored in the refrigerator or freezer.

Comparison of Dried Fruit Treatments


Feature	Sulfur Dioxide-Treated Dried Fruit	Sulfite-Free / Organic Dried Fruit
Appearance	Bright, vibrant colors (e.g., golden raisins, bright orange apricots).	Naturally darker, browner, or more muted colors.
Taste	Can have a slightly tangy, sometimes slightly chemical aftertaste.	Richer, more concentrated fruit flavor; can have a caramelized note.
Preservation	Inhibits spoilage, extends shelf life significantly.	Preserved by drying process; shelf life is shorter.
Sulfite Content	Contains detectable levels of sulfites, requiring labeling above 10 ppm.	Minimal to no added sulfites. Naturally occurring sulfites may be present.
Health Impact	Generally safe for most; poses risk to asthmatics and sensitive individuals.	Safer for individuals with sulfite sensitivities.

Conclusion

For the majority of people, consuming fruit treated with sulfur dioxide is safe and poses no health risk, as long as it adheres to regulatory standards. However, for the specific population with asthma or a diagnosed sulfite sensitivity, the risk of an allergic-type reaction is a serious concern. Awareness is the most powerful tool: reading food labels to identify the presence of sulfites is crucial for vulnerable individuals. Thankfully, the market offers plenty of sulfite-free alternatives, including organic options, ensuring that everyone can enjoy dried fruit safely. CDC Medical Management Guidelines for Sulfur Dioxide

Frequently Asked Questions

Sulfur dioxide is a colorless gas used as a preservative and antioxidant in many foods, including dried fruits. It prevents the fruit from browning or darkening during drying and storage, and it inhibits the growth of bacteria and mold to extend its shelf life.

No, it is not harmful to everyone. Health authorities classify it as 'Generally Recognized As Safe' for the general population when used within regulated limits. The risks are concentrated in a small percentage of individuals who have a sensitivity or allergy.

Symptoms can range from mild to severe and may include wheezing, chest tightness, hives, skin rashes, stomach cramps, and headaches. In rare cases, it can trigger life-threatening anaphylaxis.

Light-colored dried fruits are most often treated with sulfur dioxide to maintain their bright color. Examples include golden raisins, dried apricots, and some dried peaches and pears.

You can tell by reading the food label. Under regulations, if the sulfite content is 10 ppm or higher, it must be listed as an ingredient, such as 'sulfur dioxide,' 'sulfites,' or 'sodium metabisulfite'.

Yes, certified organic dried fruits are typically free of sulfur dioxide and other synthetic preservatives. They are a safe alternative for those with sulfite sensitivities, and their color is naturally darker.

Soaking dried fruit in water can help reduce the amount of residual sulfites. However, it may not remove all of it and can alter the fruit's texture. It is not a reliable method for individuals with severe sulfite sensitivities.