Fill Up, Don’t Foul Up the Air!

Courtesy of California Air Resources Board
Special imaging shows how you can be venting air-polluting chemical vapors into the atmosphere if you're not filling up your gas tank the right way.

Of course you know how to fill your gas tank— but are you sure you’re doing it right?

Because if you’re not, you could be spilling volatile, air-polluting vapors like ethylbenzene, toluene and benzene into the air that can create smog.

Modern vehicles and gas pumps use built-in vapor recovery systems to help keep us from letting chemical vapors escape into the air. But just in case, the County’s Air Pollution Control District (APCD) has some handy tips to make you a non-polluting, fill-up expert.

APCD constantly monitors San Diego County’s air quality and enforces regulations to protect the public health, conducting thousands of inspections a year at gas stations, auto body shops, businesses, power plants, manufacturing facilities and shipyards throughout the county. APCD also measures air pollution levels around the county 24 hours a day, seven days a week and publishes air quality forecasts every day.

So, here are five steps to help you fill your tank the right way!

Pull up so Your Gas Tank Is on the Same Side as the Pump You’re Using

  1. The idea is to get a good seal between the fuel nozzle and your tank so vapors don’t escape. Some gas stations have longer gas pump hoses that can let you stretch them over the top of your car if you’ve pulled up with the tank on the opposite side of the pump. But it’s not ideal. That stretch can create a bad seal that can let gas vapors escape into the air, helping create smog and exposing people to carcinogens.
    If you’re driving an unfamiliar car and don’t know what side of the car the tank is on, most modern cars have a gas tank indicator light on their dashboard — with a little arrow pointing to the right or left — to show you.

Don’t Remove Your Gas Cap Until You’re Ready To Insert The Fuel Nozzle

  1. This will help limit the time your gas tank is exposed and can let vapors escape. Some stations will let you insert the fuel nozzle before paying by inserting cash or running your credit or debit card; others won’t let you insert the fuel nozzle until you’ve finished the paying process. Either way, the key is this — limit the time your gas tank is open. Anytime your gas cap is off, gas vapors can escape and harm the atmosphere. Leaving the cap on until you’re ready to pump can help prevent that.

Insert the Fuel Nozzle Snugly into your Tank and Squeeze the Handle

  1. Insert the fuel nozzle fully into your gas tank, let the handle rest and use handle’s locking latch to keep the pump running until it shuts off. If you can, stand upwind to keep from breathing any vapors that might escape. 

Don’t Top Off

  1. Gas pumps are designed to shut off automatically when they sense the gas tank is full. So don’t continue to pump the handle trying to squeeze every last drop into your tank. All you’re doing is potentially spilling gas onto the ground and venting harmful vapors into the air. Topping off can also cost you money, according to APCD officials. When you top off your tank, some of the fuel you’re trying to pump can back up into the fuel line’s vapor recovery hose, charging you for gas you don’t actually get.

Remove The Fuel Nozzle From Your Tank, Put It Back In The Pump Holder And Replace Your Gas Cap

  1. Once the gas pump shuts off, tip the nozzle down and wait a couple of seconds to let any gas in the nozzle drain into your tank. Then pull the nozzle out, pointing the tip of the nozzle straight up so you don’t drip gas that can quickly evaporate into the air. Replace the nozzle into the pump and replace your cap, twisting it until you hear clicking sounds. That means you’ve got it on tight! (Here’s something else you might not know: if your gas cap isn’t on snugly, or isn’t working correctly to seal the tank, it can trigger your car’s check engine light to come on!)

There you go. Now you know how to fill up the right way — and you can help keep our air clean! For more information about the Air Pollution Control District, go to their website.



Gig Conaughton is a communications specialist with the County of San Diego Communications Office. Contact