Sunwing did not spray during descent this year as far as I know, nor the last 3 flight with them. They may be using the “residual” method of spraying. Funny thing, Sunwing is not on the Transport Canada list.
Disinsection involves the spraying of insecticide in various areas of the aircraft, including the flight deck and the passenger cabin. This procedure, which is intended to prevent the transmission of disease by insects, has been in place for a number of years in various parts of the world and has been considered to be a necessary public health measure in many International Civil Aviation Organization (ICAO) Contracting States.
There are three methods of disinsection that have been found to be effective. The first method, known as “blocks away” disinsection, takes place after passengers have boarded and the doors have been closed, prior to take-off. The aircraft is treated by crew members walking through the cabins discharging approved single shot aerosols in the prescribed dosage. Cargo holds are sprayed prior to departure and the flight deck is sprayed prior to boarding by the crew.
The second method consists of pre-flight and “top-of-descent” spraying. It is similar to “blocks away” except that the aircraft cabin is sprayed on the ground prior to passengers boarding, using an aerosol containing a residual insecticide. At the time this method is used, lockers can be opened and there is no inconvenience to passengers. Pre flight spraying is followed by a further in-flight space spraying of the cabin carried out at “top of descent” as the aircraft starts its descent to the arrival airport.
The third method consists of residual treatment. The internal surfaces of the aircraft, excluding food preparation areas, are regularly sprayed with a residual insecticide to ensure that if an insect gains access to the aircraft and lands on a surface, it will receive an effective dose of insecticide. Insofar as efficiency, convenience and safety of passengers with predisposition to adverse health reactions are concerned, the residual disinsection method provides the most assurance. It remains effective for eight weeks and does not expose crews or passengers to aerosol sprays.