As a Canadian registered air carrier, WestJet is required by several countries to spray insecticide in the flight deck and guest cabin prior to traveling to those countries. This is a preventative measure against the importation of foreign insects that may carry disease or damage crops.
WestJet uses Permethrin #216, an insecticide approved by the World Health Organization (WHO) for application onboard commercial aircraft. According to the WHO, short-term exposure when spraying this insecticide has not been found to cause any adverse health effects.
More information on disinsection can be found on the Transport Canada website at:
or at the U.S. Department of Transportation website at: