It’s the airline PA request that will be familiar to millions: please refrain from eating peanut-based foods during the flight to protect a passenger with allergies.
But now the largest review of its kind suggests aircraft nut ban announcements are “unlikely to be effective”, and may even give people with nut allergies a false sense of security.
There is no evidence for the commonly held belief that nut allergens can be spread through aircraft ventilation systems, say allergy and aviation medicine specialists in a paper published in the Archives of Disease in Childhood.
Allergen residues on surfaces, such as tray tables, and seat-back video screens, pose the main risk – a risk that is likely heightened by the fast turnaround times deployed by many low-cost carriers, the experts suggested.
And allergic reactions to foods are about 10 to 100 times less common during flights than they are “on the ground”, they said, although they acknowledged that this could be due to passengers with food allergies taking more precautions when flying.
People with nut allergies should not be worried about the spread of allergens through aeroplane air conditioning systems, the academics concluded, but they should ask to be allowed to board first so they can clean their seat area.
Experts from Imperial College London and Aviation Medical Consultancy conducted an analysis of studies on nut particles travelling through ventilation systems, to examine the common perception that peanut or tree nut particles can be transmitted through aircraft ventilation systems.
Their analysis, funded by the UK Civil Aviation Authority and the UK Medical Research Council, concluded that research studies show “no evidence to support airborne transmission of nut allergens as a likely phenomenon”.
“Announcements requesting nut bans are not therefore supported, and may install a false sense of security,” they wrote. Airlines should instead give people with allergies “pre-boarding” so they can wipe down their seat area.
But the authors said that people at risk of a severe allergic reaction – also known as anaphylaxis – should carry two pre-filled EpiPen devices at all times – including when flying. Airlines should also consider including a separate supply of “general use” adrenaline autoinjectors.
Prof Paul Turner, an expert in anaphylaxis and allergy at the University of Sydney and Imperial College London, said: “People shouldn’t be worried about what food is being transmitted in the air when they fly.
“We didn’t find any evidence that nut particles could travel through the cabin ventilation system on aeroplanes and cause reactions. The one thing people must do to protect themselves is to clean their seat area.
“Allergenic food is really sticky, and can be found on seat surfaces, table tops, and seat-back entertainment screens. People touch these surfaces, and then the allergens can be transferred to their mouths.
“If food-allergic people can board first, and have time to clean their seat area with something like a baby wipe or antibacterial wipe, they are much less likely to have accidental reactions.”
He added: “We’re having discussions with a number of major airlines as well as patient groups and anaphylaxis charities to see if we can get some consistent changes in airline policy across airlines operating out of the UK and internationally, to reflect what the evidence is and really make a difference to food-allergic passengers.”
Simon Williams, chief executive of Anaphylaxis UK, added: “A key take-home message is the importance of passengers cleaning their seat area, including the tray table and the seat-back entertainment system.”
