In A History of Wine In America, Volume 2, Thomas Pinney recaps some of the maneuvering from the 1980s that led to this warning. A group tried to have ingredients listed on wine labels as early as 1972. After over a decade of ping-ponging between agencies, proposals getting rebuffed from the industry, and ultimately a legal challenge that succeeded in striking it down, ingredient labeling was off the table.
But the forces of “neoprohibitionism” had started gathering steam and in Senator Strom Thurmond, they found their man. This time, Pinney writes, “their goal was not to inform but to frighten.” Initial efforts to get a government warning were stymied, but they scored a victory in getting “CONTAINS SULFITES” to appear on labels starting in 1987. The following year, the government warning language on labels also passed and went into effect. While a small portion of the population is allergic to sulfites, an allergist once told me that those who are allergic generally have preconditions, such as asthma. Further, the reactions are most often severe and may include anaphylaxis (note: they don’t cause headaches).
So if you’ve ever wondered why dried fruits that have higher levels of sulfur than wine contain no government warning, know you know why. First, they’re regulated by different agencies (TTB vs FDA). Second, there’s no anti-dried fruit lobby.