Sulfites (sulfiting agents; SO2 equivalents)

Additive

Sulfites are preservatives that slow spoilage and stop foods from turning brown. They are used in dried fruit, juices, wine and other foods. Labels may name sulfur dioxide, sulfite, bisulfite or metabisulfite. These agents are commonly measured as sulfur dioxide.

Also known as

sulfites · sulphites · sulfiting agents · sulphiting agents · sulfur dioxide · sulphur dioxide · sodium sulfite · sodium sulphite · sodium bisulfite · sodium hydrogen sulfite · sodium metabisulfite · potassium bisulfite · potassium hydrogen sulfite · potassium metabisulfite · potassium sulfite · calcium sulfite · calcium bisulfite · calcium hydrogen sulfite

Why PRūF tracks it

Sulfites can trigger severe reactions in susceptible people, especially some people with asthma, while animal-based exposure concerns and newer observational disease associations warrant attention without proving chronic harm from ordinary intake.

Read the research

Most people tolerate sulfites, but susceptible people can develop breathing difficulties or other allergy-like reactions, occasionally severe. Some people with asthma are particularly sensitive. A reaction to wine alone does not establish sulfite sensitivity, because wine contains other potential triggers. In 2022, EFSA withdrew its temporary acceptable daily intake because the evidence was insufficient to retain it.

EFSA instead compared estimated food exposure with an animal nervous-system reference point. The opinion, amended in November 2025, identifies potentially inadequate margins for high consumers across all age groups; this does not show that ordinary servings cause nerve damage. A separate 2025 report modeled possible lower food limits, without establishing a new safe intake or changing the law. Recent French cohort studies found associations between certain sulfite exposures and cancer, diabetes or hypertension.

Results differed between individual additives and the combined group, and several group results were not statistically clear. These overlapping observational studies cannot prove causation. Laboratory gut findings also need confirmation in people. Labels help identify sulfites but usually do not reveal the amount present, and disclosure thresholds are not personal safety thresholds.

Research reviewed on September 5, 2026 · 12 sources