Welcome to the County of Berks
Is Paint Hazardous?‚Äč That Depends
Attention, all Berks County residents -- latex paint is not a hazardous material!
Take the lid off (latex paint cans) and let the paint dry. You can also use sand, cat litter, shredded paper, or saw dust, to soak up the paint. Scrape out the contents and flatten the can. Then it can be thrown out.
Trash haulers often reject paint cans. The main reason trash haulers will not pick up paint cans because they don't know what is in them. They don't have time to read labels. Trash haulers avoid full paint cans because they can explode and cause major messes for the trash haulers, trash trucks and streets.
Aerosol cans are not accepted in any of the recycling programs throughout the County. Once aerosol cans are emptied they can be thrown out. If they are marked as poisonous then they must be deposed of at a Household Hazardous Waste Collection Program. 
When getting ready to paint, buy just the amount you need to do the job. When you avoid buying too much at the start -- what's called "source reduction" -- there's less chance that leftovers land in the trash later.
Suppose, despite your best efforts, you still have leftover paint? Easy! Store paint properly for future touch-ups or small projects. Just make sure the lid fits securely so the paint doesn't leak, and store the paint can upside down. The paint will create a tight seal around the lid, keeping the pint fresh until you need it again.
You still can't use up your leftover paint? Donate it. There are civic groups, clubs, churches, school, theater troupes and organizations in your area that would really appreciate the extra paint -- especially since the price is right! Some donations may even be tax deductible!
If you've tried your very best to use it up or donate it and you still have leftover latex-based paint, then there's a last resort: dry and discard it. First, air-dry leftover latex paint out of the reach of the children and pets. To speed up' add some absorbent material like cat-box filler. When dry, smash the can and it's out the door with the normal trash.
Remember, air-drying liquid solvent-based paint is generally not recommended, but if the paint has already solidified in a close can, after smashing the can, you can dispose of it in the regular trash.
When leftover solvent-based paint is still liquid, you shouldn't put it out with the regular trash. Instead, save it for collection. Check community sources and include the leftover paint in special household waste or paint collection programs.
The above information was from the National Paint & Coatings Association.