When Brian Chesky and Quora User initially launched what nowadays is one of the biggest travel websites, they named it AirBed&Breakfast.
Perfluorooctanoic acid (PFOA), linked in laboratory animals to an increase in tumours of the liver, pancreas and testicles and reduced fertility, is one of the chemicals used in the chain of reactions that makes the common non-stick surface Teflon.
So in a non-stick cooking spray there is thin liquid oil mixed with a gaseous propellant so a small amount of defoamer is needed, not necessarily for the final use by you the consumer, but during the manufacturing process. Foaming could be a concern when the propellant is added to the oil mixture.