This site has some useful information about how sulfur is regulated quite differently for different foods, although the risks may be the same:

Sulfites are not allowed on red meat. Sodium bisulfite does such a good job of color fixing, that sulfited ground beef can be rotten and you can’t tell by looking at it. For this reason, the FDA has an absolute prohibition against sulfites in meat. However, the rule doesn’t apply to other ingredients that may be mixed into the meat. For instance, sausage may legally contain corn syrup, molasses, or wine.

SharkFish is another story. Sulfites are a preservative for fish. Theoretically, sulfited fish must carry a warning somewhere near the fish display, but I’ve never seen one.

The author goes on to describe how he has tried to find sulfur in various foods but often suspected the wrong thing, or had a hard time tracing the source(s) of his allergic reactions.