Yes, your car's recirculate button helps reduce air pollution in your vehicle

Smoke from wildfires frequently lowers the quality of air across much of the U.S., triggering air quality alerts in those areas.

Many people online are looking for ways to protect themselves from the smoke. On Twitter, two meteorologists claimed that using the recirculation button in your car — which is often encouraged to maximize your A/C efficiency — can help keep outside air from getting inside your vehicle when it's smoky outdoors. But is that true?

THE QUESTION

Does your car's recirculate button help reduce air pollution in your vehicle?

THE SOURCES

• AutoDeal
• Eden Tyres & Servicing
• Ken Brown Motors
• Fuel Freedom Foundation
• A study published in Environmental Science & Technology
• University of Rochester Medical Center
• Rob Poinsett, auto body technician at Team Collision Center of Ewing in Ewing, New Jersey

THE ANSWER

Yes, your car's recirculate button helps reduce air pollution in your vehicle.

WHAT WE FOUND

The recirculate button in your car does help reduce some air pollution from entering your vehicle when the air quality outside is poor or smoky. The air recirculation setting in most vehicles usually appears as a button with an arrow turning around inside the shape of a car.

The recirculation button takes the air within the car and recycles it inside the cabin instead of pulling fresh air from outside, according to car experts at AutoDeal, Eden Tyres & Servicing and Ken Brown Motors. They all recommend pressing the recirculate button to reduce the air pollution that gets inside the vehicle.

“It's not a foolproof way, but it will keep most of the contaminants out for a small period of time,” Rob Poinsett, an auto body technician at Team Collision Center of Ewing in Ewing, New Jersey, told VERIFY.

A 2013 study published in the Environmental Science & Technology journal measured how much air pollution reaches people inside their vehicles. The researchers found that using the recirculate button significantly reduces the amount of pollution that can enter a typical car, keeping about 80% of those pollutants outside. 

In addition to stopping some air pollution from getting into your car, the recirculation button boosts the air conditioner to help the cabin get as cold as possible as quickly as possible, reduces pollen from getting into the vehicle and can help prevent strong outdoor odors from entering the car. It also helps keep your air filter cleaner longer.

But health experts at the University of Rochester Medical Center say the best thing you can do to protect yourself when the air quality is poor is to stay inside if possible, avoid strenuous activity outdoors, wear an N95 mask or respirator when outside and use an indoor air cleaner if able. Visit AirNow.gov to check on the air quality in your area.

The Associated Press contributed to this report.