Singapore Airlines is the most recent airline to reconsider serving nuts on the plane. A recent incident with a toddler going into anaphylactic shock while on board is the reason behind the change.
The child was served a nut-free meal but seemed to have an allergic reaction just from being around other people who were eating nuts on the plane. Current nut-free airline cabins include those of Qantas, Air New Zealand, and British Airways.
The airline handled the situation by removing nuts in his proximity and his family gave him allergy medication while the plane finished its last hour in flight.
Even when an airline doesn’t serve nuts it can be challenging to become completely nut-free since people are also allowed to bring their own snacks on board.