Margy Natalie wrote:
to the sufferer via airborne particles. My sister had one kid in her class who
was so allergic she couldn't grade papers in her kitchen for fear off passing

If such a ridiculously allergic person is flying, shouldn't s/he be
wearing some sort of mask then? Otherwise, the airlines and airports
could go through incredible amounts of expense and not even make a
dent in effectiveness of filtering out peanut particles. And then
consider that probably a good number of airports are located fairly
near peanut farms, so there is really nothing that can be done on a
global basis.