Generally, aerosol spray cans—like your average cooking oil spray—have much more potential for causing accidents than other recyclable material because they’re pressurized. The cans themselves typically contain a liquid, like hair spray or an air freshener, and a propellant, a gas that pushes the liquid out to form a cloud or spray. (Since the late ‘70s, manufacturers have phased out the use of chlorofluorocarbons or CFCs as propellents after they were revealed that they depleted the ozone layer.)
Recycling aerosol cans is actually easy, depending on your local curbside program’s rules (and the can is valuable to recyclers because of its aluminum, steel, and other metal components). But, as Recycle Nation points out, a pressurized can also presents serious hazards to recycling facility workers. “Aerosol cans with even a little paint or bug spray still contain some of that propellant, and they can blow up under pressure, injuring sanitation workers or damaging equipment.”
Before you recycle your can, first perform an online search for your program’s rules. Depending on your local program, they might accept your cans in your blue bin. And if your can has a plastic cap, don’t forget to throw that in with your other plastics.
There is one exception, however. If your can is full or near-full, it’s likely you can’t recycle it in your bin, as the remaining liquid is considered hazardous waste that could pose a danger to the environment if it were to leak (like insecticide products, for example). Instead, find a hazardous waste facility near you that will accept your cans, using Earth911's search directory. And again, check your program’s rules on whether they accept full cans or not; certain facilities may be equipped to handle them and separate the liquid and can to dispose of them properly.
And as Recycle Nation suggests, use up the remaining liquid or find a friend who might need it before you decide to recycle it. And, as always, keep your Pam cans away from any hot stoves.