Used in wine, dried fruit and some foods. Can trigger reactions in some people with asthma, so they must be declared.
Job
Antimicrobial and antioxidant; keeps dried fruit bright.
Sensitivity
A small portion of people, especially with asthma, react to sulfites. US labels must declare ≥10 ppm.
Evidence & sources
US labels must declare sulfites at 10 ppm or more, because they can trigger reactions in some people with asthma. Evidence: regulatory. Known: US labeling regulation. Unknown: Most people tolerate sulfites without problems. Source: US FDA, 21 CFR 101.100 (Current revision).