Because they come from the sea, sea vegetables sometimes hold tiny dried shellfish such as snails, periwinkles, and mussels within their fronds. We do our best to remove these as we sort and package, but they occasionally get through anyways.
Seaweed itself is not considered to be an allergenic food. Case reports of allergic reactions after eating sea vegetables are exceedingly rare; we’re aware of just one report worldwide as of 2020!
Our facility does not process any tree nuts, peanuts, dairy, eggs, wheat, crustacean shellfish, or other seafood, so there’s no danger of cross contamination from these common allergens during processing or packaging.
Although in 40+ years we've never had a customer report an allergic reaction after eating sea vegetables, we recommend that each person evaluate the risk for themselves.