As shocking as this may be, it's true.  In fact, if you look on the back of any can of everyday, household nonstick cooking spray, you'll see that it clearly states warning about the negative health effects that may be caused by huffing the spray.  The main ingredient which causes the intoxicating effect is the propellant, nitrous oxide, which is commonly known as "laughing gas."  Nitrous oxide is also found in whipped cream cans, another commonly abused household item. 

Kids "huff" these chemicals, deliberately concentrating them and then inhaling them, because they're cheap, readily available, and not suspicious if parents find them missing.  So, if you find that you've recently been going through a lot more nonstick spray, it might be time to sit the kids down and have a little chat.

For more information about this, and other interesting facts about nonstick cooking spray, check out this article.