What is the proper way to dispose of aerosol cans?

In general, aerosol cans are capable of holding either compressed gas or liquid. According to EPA guidance, if the can is sent for scrap metal recycling, the can and its contents are exempt from regulation as a scrap metal under 261.6(a)(3)(iii).

The act of emptying the can may be an exempt recycling activity under 261.6(c), and any residues from emptying the can would be regulated if they are listed or exhibit a characteristic of hazardous waste.

If the can is sent for disposal, both the contents of the can and the can itself are subject to regulation. To dispose of the aerosol can as nonhazardous, the can must be RCRA empty according to 261.7, and the can itself must not qualify as a hazardous waste. If the aerosol can is holding a compressed gas, it is unclear whether the act of venting to render the can empty would constitute treatment. This question must be answered by the appropriate EPA Region or authorized state.