The EU _nearly_ solved this (or at least solved for 99% of cases) by mandating 14 allergens (or, well, problem ingredients; gluten and dairy are more likely to be intolerance issues than actual allergies) which must be declared. They then fumbled this by not specifying a canonical ordering; number 7 is _usually_ dairy, say, but the ordering is not actually mandated. So you still need to know the local language.

(My personal favourite quirky use of the fact that there is no mandated order is by a Kosher deli in Dublin; they don't have numbers for dairy, crustaceans or mollusks because, well, it's Kosher so I suppose it can be assumed. They use the free'd-up address space to call out wheat, rye, barley and oats, which is going beyond the obligation; these can all be grouped together).