To empty these cans, it is important to open the safety valve or to puncture the can. Aerosol cans containing compressed gases or liquids, especially when these substances are flammable, toxic, or corrosive, should only be punctured under strictly controlled conditions. Emptying aerosol cans at facilities authorized under the Environmental Protection and Enhancement Act allows for the collection and destruction of active ingredients prior to the recycling or disposal of the cans.