Sulfites are chemicals that are commonly used as preservatives for a range of different types of foods and beverages. For example, sulfites are often added to shellfish to prevent discoloring, processed foods to give them a longer shelf-life, and dehydrated fruits and vegetables to preserve them. You can also find these chemicals in soft drinks and alcoholic beverages like beer and wine. In addition, some medications contain sulfites, which work to keep the drugs stable and effective. Sulfites are also used in cosmetics.
The US Food and Drug Administration (FDA) labels sulfites as Generally Recognized as Safe (GRAS) in a variety of products. But, there are restrictions on how these agents can be used. For instance, the FDA does not allow this preservative on the raw vegetables that you find at your favorite salad bar, since sulfites would make them look fresh when they might not be.
And since the 1980s, the FDA has made companies identify food, drinks, and medications that do contain sulfites. Why the need for this labeling? The FDA made the ruling after reports came in that people were having allergic-like reactions—in some cases severe—after eating or drinking a product containing sulfites.
You are considered to be sensitive to sulfites if you have an allergic-like reaction after consuming or applying this preservative. The symptoms, which range from mild to severe, can include:
In extreme situations, a life-threatening allergic reaction called anaphylactic shock may occur, where the person is not able to breathe and experiences a drop in blood pressure.
How common is this sensitivity? Actually, the FDA estimates that the number of Americans who are sensitive to sulfites is low. However, people with asthma seem to have a higher risk of experiencing a reaction to these chemicals.
If you think that you may have sulfite sensitivity, one way an allergist can diagnose the condition is by doing a food challenge. This involves giving you a very small amount of sulfites and closely observing you for any reaction. If you do not have any symptoms, the amount you are given will slowly be increased. If you do have a reaction, medication will be given to reverse your symptoms and tests can be done to check your lung function. A food challenge should only be done under close supervision by an allergist.
If you are sensitive to sulfites, the best approach is to avoid these chemicals. This can be difficult considering how common sulfites are in the foods we eat and the fact that they come in so many different forms—like sulfur dioxide, potassium bisulfate, and potassium metabisulfite.
Despite these obstacles, there are ways that you can live a sulfite-free lifestyle.
Here are some examples of products that commonly contain sulfites:
Since there are many other products that contain sulfites, carefully check the food label.
Keep in mind, though, that food prepared from bulk ingredients, like bakery bread with raisins in it, would have the sulfites label on the original bulk packaging. And, while the grocery store should list sulfites on the bread’s label, ask the store manager if you are concerned. You can use the same approach when dining out by asking the waiter or chef about the use of sulfites.
Since sulfite is such a common preservative, it is challenging to fill your kitchen with sulfite-free products. But there are options available, like specialty grocery stores and websites that sell health foods.
Sulfites are added to many prescription and over-the-counter medications. Surprisingly, this preservative is often found in drugs used to treat asthma and allergies. Other types of medications that may have sulfites include:
Read the drug label carefully. If you have any questions, talk to your doctor and pharmacist.
If you have been diagnosed with a severe allergy to sulfite, carry any emergency medication with you at all times. Ask your doctor which medication is right for you. You can also wear a medic alert bracelet to inform those around you that you have a food allergy.
In the case that you do have a reaction, get emergency medical care right away.
American Academy of Allergy, Asthma &Immunology
Food Allergy Research & Education
Allergy Asthma Information Association
Allergy testing. American College of Allergy, Asthma & Immunology website. Available at: http://acaai.org/allergies/treatment/allergy-testing. Accessed May 4, 2017.
Garcia-Gavin J, Parente J, Goossens A. Allergic contact dermatitis caused by sodium metabisulfite: a challenging allergen: a case series and literature review. Contact Dermatitis. 2012;67(5):260-269.
Grotheer P, Marshall M, Simonne A. Sulfites: Separating fact from fiction. University of Florida website. Available at: http://edis.ifas.ufl.edu/fy731. Accessed May 4, 2017
Sulfites: FDA guide to foods and drugs with sulfties. The Extension Toxicology Network website. Available at: http://extoxnet.orst.edu/faqs/additive/sulf_tbl.htm. Accessed May 4, 2017.
Sulphites—priority allergens. Health Canada website. Available at: http://www.hc-sc.gc.ca/fn-an/pubs/securit/2016-allergen_sulphites-sulfites/index-eng.php. Accessed May 4, 2017.
Last reviewed May 2017 by Michael Woods, MD, FAAP Last Updated: 5/4/2017