Ban all nuts! A danger to life! And while you’re at it ban gluten products too! And alcohol (would have been a Class A drug if categories had been around when it was first introduced!) Seriously, we have to be mindful of those with allergies or disabilities which are in fact often hidden. In this case, a directive by airlines for passengers to list allergies might help. But what about buses/trains/public places etc? A manufacturer/restaurant should obviously state the ingredients in the product or meal, of course. Otherwise I think it is up to the individual to take responsibility and anticipate the co operation of other people, which, considering the seriousness of a potential outcome, should be forthcoming. We cannot legislate for every single danger in the world, unfortunately. By the way, I do have a family member who is severely gluten intolerant (coeliac disease) but she does manage very well.