The International Civil Aviation Organization reports that most airlines use permethrin and pyrethroid, both are suspected endocrine disruptors, and permethrin may be a carcinogen. The Northwest Coalition for Alternatives to Pesticides (NCAP) points out that pesticides cause even greater harm on airplanes, where up to 50% of the air in the cabins is recycled. "Pesticides break down slowly in the enclosed, poorly ventilated aircraft," says a NCAP spokesperson.

The airlines are not required to inform passengers at ticket purchase of flight sprays, and there is also no control over how much pesticide is applied on the aircraft. The Association of Flight Attendants reported in 2001 that one airline used 50-60% more pesticide than the maximum recommended by the World Health Organization. Between 2000 and 2001, one cabin crew union received complaints of pesticide-related illness on more than 200 flights. Many complaints cite damp surfaces and pesticide odors in crew rest compartments. Crews and passengers have reported sinus problems, swollen and itchy eyes, cough, difficulty breathing, hoarseness, skin rashes/hives that vary in intensity, severe headaches and fatigue, and heightened sensitivity to other chemicals. Some crew members have medical documentation of reactions consistent with nerve gas exposure, such as blood, optic nerve, and nervous system abnormalities.