If someone is allergic to peanuts or some other ingredient, they take their own life in their hands when they eat food that doesn't have the ingredients listed. Those people usually carry EpiPens as a safeguard.

If one passes away (which happens, though not as often nowadays) there needs to be proof the person was intentionally given something the issuer knew would do harm.

It's really hard to prove, and genuine mistakes happen (parent giving a child a snack with wheat or peanut in it, that kind of thing).