“FDA will take the existence of natural levels of sulfites into account in determining whether a shipment of food complies with the labeling requirement of this regulation. The Agency has no reason to believe that these naturally occurring sulfur dioxide yielding compounds would have adverse reactions in sulfite-sensitive individuals. These foods have been consumed safely. There is no record of sulfite-type adverse reactions to Allium and Brassica vegetables that do not contain added sulfating agent”.
Mustard seed and mustard is considered as a priority allergen in Canada and the EU and has regulatory labelling requirements as such. Currently the United States does not consider this as an allergen and does not regulate use levels or labelling requirements