The process of applying pesticides in aircraft to kill insects is called disinsection. Some countries require that inbound flights be treated with pesticides to prevent the spread of insects or diseases carried by insects.

Disinsection methods can include spraying the aircraft cabin with an insecticide either before or after passengers board, or while in flight or by treating the aircraft's inside surfaces while passengers are not on board.

Aircrew and passengers are exposed to pesticide during aircraft disinsection or by contact with treated surfaces within the aircraft. The insecticides can be effective up to eight weeks as they stick to the walls, seats and other materials inside the cabin.

You can unknowingly be exposed to insecticides even on flights that don't require disinsection, including flights within the continental United States or any other country, because aircraft treated with insecticides can be used on multiple flight routes.

Aircrew may spray a pesticide in the aircraft cabin after the aircraft leaves the gate and/or before it lands.
Ground crew (including maintenance or cleaning staff) may treat surfaces inside the aircraft with a pesticide before aircrew and passengers board. Additionally, the ground crew might enter an aircraft shortly after disinsection and before treated surfaces have dried.

Pesticides used for aircraft disinsection are mixtures including solvents, propellants, surfactants, and synergists.

Impacts of pesticides on our health

Pesticides are poisons and, unfortunately, they can harm more than just the “pests” at which they are targeted. They are toxic, and exposure to pesticides can cause a number of health effects. They are linked to a range of serious illnesses and diseases from respiratory problems to cancer.

The sprays can cause allergy or asthma symptoms, allergic sensitization, asthma symptoms, and even anaphylaxis, a sudden and very severe allergic reaction, that have been reported related to exposure to commercial aircraft disinsection products.

Pesticides can cause harmful effects over an extended period, usually following repeated or continuous exposure at low levels. Low doses don’t always cause immediate effects, but over time, they can cause very serious illnesses.

Long term pesticide exposure has been linked to the development of Parkinson’s disease; asthma; depression and anxiety; attention deficit and hyperactivity disorder (ADHD); and cancer, including leukaemia and non-Hodgkin’s lymphoma. (sic Pestizide Action Network UK ©)

There is no single set of standards for how aircraft disinsection is conducted. It is unknown whether all aircraft disinsection adheres to the WHO guidelines regarding disinsection, label directions, and good occupational hygiene practices. Reports from passengers and aircrew suggest that there are major differences in how disinsection is performed.

Some insects are resistant to the pesticides used in aircraft disinsection.

Some researchers doubt the usefulness of chemical disinsection, and are concerned about the health effects on exposed crew and passengers.