Growing up, my household of six exclusively road-tripped to any vacation destination. Considering my parents were very much outnumbered, having four daughters within a five-year window, I completely understand the rigid insistence on taking the car, especially now that I have my own kiddos. In the 90s, though, long drives in a backseat cramped with coolers, pillows, and other odds and ends felt like torture much of the time. Stale air was a problem, too, and one that my dad addressed regularly with “air changes.”

He’d suddenly (and without warning, for “comedic effect”) roll down all the car windows and demand the back row pop open their window hinges. After a healthy dose of highway gusts, he’d declare the air “changed” and the windows would go back up. We continue the tradition on our own road trips today, and it turns out, there’s science behind why regularly changing your car’s air is a really good idea.

Change your car’s air as often as possible to avoid toxicity

A 2024 Swedish study from Umeå University found that car interiors release chemicals called SVOCs, which can affect hormones and health. These chemicals come from plastics, flame retardants, and other materials inside your car. On hot days, the levels of these chemicals can be up to 40,000 times higher than on cooler days.

At a minimum, rolling your windows down before driving and keeping the ventilation system on (without using recirculate) helps clear out these chemicals. The study showed that cars with active ventilation had much lower chemical levels.

Aside from SVOCs, running your car’s heater on recirculate can build up C02. Experts warn of the same phenomenon in your home, but few people understand that the same buildup happens in your car…perhaps in even higher concentrations since the space is so much smaller.

So, whether it’s summer or winter, letting fresh air in is a simple way to keep your car’s air cleaner and healthier. And anyway, it’s a tiny way of reconnecting with our breath.