Next time you fill up on gas, make sure not to top off your gas tank. Once the nozzle clicks off the first time, the gas you're paying for is not going into your tank. You’re wasting money on gas that is stuck in the hose or getting ready to spill on the next person. Topping off your tank damages the vapor recovery system that's designed to minimize the amount of vapors released into the air. Gas vapors pollute the air with volatile organic compounds that are harmful to our lungs and our environment.