Non-Toxic Insecticide

I think my favorite airline experience so far has to have been the flight from Abu Dhabi to Delhi.  As we were preparing to take off, the flight attendants announced, "Ladies and gentlemen, per legal requirements, we must now spray the plane with a non-toxic insecticide."

Non-toxic insecticide?  That sounds like a pretty useless insecticide.

"The insecticide is not harmful, but if you would like to cover your mouth and nose, you may."

I'm pretty sure covering my mouth and nose is not going to be an effective approach for avoiding insecticide inhalation given that I will be breathing the same recirculating air for three hours.

One of the flight attendants proceeded to walk down the aisle with three misting aerosol cans, squinting her eyes and covering her nose and mouth.