When you’re jetting off from Bristol Airport this winter to escape the chilly weather, you may notice cabin crew spraying a mysterious liquid into the air before take-off.
Then, on some flights, you won’t see this happen at all.
So, what is it?
Here’s everything you’ve ever wondered about the process, so you can spend less time worrying and more time thinking about sunning on the beach:
Why do they spray the inside of the aircraft?
The process is known as disinsection and is required on flights to and from certain destinations to prevent infectious and contagious diseases, a Civil Aviation Authority spokesman said.
It’s mainly sprayed in countries where diseases are spread by insects, such as malaria and yellow fever.
The World Health Organisation has a set of guidelines outlining when and where it is necessary.
There are numerous countries where the aircraft is routinely disinsected before take off, Manchester Evening News reports.
This includes Cuba, Jamaica, India, Australia and New Zealand, among others.
The World Health Organisation website says: “There have been a number of cases of malaria affecting individuals who live or work in the vicinity of airports in countries where malaria is not present, thought to be due to the escape of malaria-carrying mosquitoes transported on aircraft.
“Some countries, e.g. Australia and New Zealand, routinely carry out disinsection to prevent the inadvertent introduction of species that may harm their agriculture.”
In 2012, there was a Dengue outbreak in Madeira – the first outbreak of such disease since the 1920s.
What is the procedure used to disinsect the aircraft?
These are the three procedures used to disinsect the aircraft, according to the World Health Organisation website:
1. Treatment of the interior of the cabin using an insecticide spray just before take-off
2. A spray of the interior of the aircraft before passengers get on board using a residual-insecticide aerosol, as well as inflight treatment with a spray before landing
3. Regular application of a residual insecticide to all internal surfaces of the aircraft, except food preparation area
Is the spray dangerous?
The website says that the spray poses no risk to health, despite passengers sometimes complaining of feeling ill after it’s sprayed.
It states: “Passengers are sometimes concerned about their exposure to insecticide sprays during air travel, and some have reported feeling unwell after spraying of aircraft for disinsection.
“However, WHO has found no evidence that the specified insecticide sprays are harmful to human health when used as recommended.”
Want more news?
To subscribe to our daily newsletter, enter your email address into the box at the top of this story.