There's mud. Some wrappers and crumbs. Something spilled once. (You don't know what it is, but the sticky residue is still there.) And maybe there's some sort of interesting smell going on. Yep, we're talking about your car. And more specifically, cleaning it (or, you know, not).
Your car is a transitional hub between the real world and your home, Kelly Reynolds, PhD, professor at the University of Arizona Zuckerman College of Public Health, tells LIVESTRONG.com. What that means: You pick up microbes (read: germs) out at a restaurant, work or an event and then transfer them to your car. "And those microbes sort of sit there. We find a lot of germs in cars," Reynolds says.
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But car cleaning — especially a deep clean — doesn't happen at the same clip as your home where you might sanitize the bathroom and kitchen on the regular, Reynolds adds: "Cars are part of our cycle of life — and yet, they are not part of our cycle of cleaning."
What Do We Mean By 'Deep Cleaning,' Exactly?
Deep cleaning is more than just taking the wrappers and empty cups out of your car (though you should do that, too!) — it’s cleaning the upholstery and wiping down high-touch surfaces, says Reynolds. You might also vacuum the inside and take out the floor mats to wipe them down to get some of the built-up dirt or crumbs out of there. And it definitely includes washing a car seat if you have a baby or little kid, she adds.
The Possible Effects of Never Deep Cleaning Your Car
Leaving your car interior grimy isn't just unpleasant — it may lead to health problems, too.
1. Your Hands Easily Pick Up Bacteria (and That Can Transfer Into Your Mouth)
Your hands are germ magnets, which is why there's a public health recommendation to wash them often.
"In our research, we've put bacteria on peoples' hands and had them go about their day. We find that bacteria later in the car — the car interior gets contaminated just like everywhere else," Reynolds says. The problem is, you touch the interior with your hands, and then you touch your face.
In a July 2022 study in Ergonomics, researchers analyzed 31 hours of videos of drivers in their car and found that people generally touch their face 26 times per hour, for about four seconds per touch. In about half of contacts, people touched mucous membranes (present in your nose, mouth and eyelids). That's precisely how germs enter into the body, and how they can potentially make you sick (though there isn't clear data on how many people get infected with a virus from their cars).
In addition, earlier research has found staphylococcus and propionibacterium (a bacteria that causes acne) present on high-touch areas, like the steering wheel, gear shifters and center console. These skin bacteria get deposited onto surfaces when you touch them with your hands. The researchers point out that skin microbes can also cause a stink, which may contribute to car odor.
It's best practice to wash your hands when you come home. Keeping hand sanitizer in your bag or car and using it in the car is also smart. And make sure you sanitize your hands before eating anything (and maybe don't eat in your car if you can help it).
2. Germs Grow on Old Pieces of Food
You know that old fry that slipped in between your seats? Or the crumble of granola bar. Or that milky coffee drink that spilled when you needed to take a sudden stop?
"Food particles attract germs, and mold and fungus grow right away," Reynolds says. "If it's food for us, it's food for [microbes], too."
Remove uneaten food and wrappers from your car on the regular.
3. Dust Can Build Up
Dust doesn't just mar the look of your car's dashboard — it also carries chemicals, such as flame retardants added to materials during manufacturing, which decrease the air quality inside your vehicle, notes a July 2019 study in the International Journal of Environmental Research and Public Health. In addition to the dash, dust also accumulates in car seats and car floor mats.
Additional research has detected an abundance of dust mites present on most drivers' seats and child car seats, per a 2015 study in the Annals of Agricultural and Environmental Medicine. Researchers found that over 12 percent of driver seats and 15 percent of child car seats contained high enough levels of dust mites that could trigger indoor allergy symptoms.
How to Clean Your Car's Interior
A car's surfaces are not always easy to sanitize — there are nooks and crannies to work around. But there are ways to fit "good enough" cleaning into your regular routine without adding stress to your already-busy life.
1. Remove Clutter
Bag up any trash, wrappers, wayward pieces of food, empty cups and anything else that does not need to be in your car.
Now's the time to suck up pet hair, piles of crumbs, dirt and dust off of seats and floors. A wet-dry vacuum cleaner can get the job done quickly.
Try one of these:
3. Spray It Down
Use a disinfectant spray that's designed or safe for the material in your car's interior, whether that's a leather, vegan leather or upholstery. "It's a good idea to spray seats down, since we sweat and eat in our cars," Reynolds says.
Regular sanitizing is a maintenance practice that can help keep seats clean, and then you can use an upholstery cleaner (below) less often.
4. Wipe on the Regular
Reynolds keeps sanitizing wipes in her car and wipes down hard surfaces (the steering wheel, dash, displays and knobs). Use an alcohol-based wipe, not one with bleach, as that can harm interior surfaces.
Try Armor All Car Cleaning Wipes ($4.18, Amazon or Walmart.com).
5. Clean Upholstery
Use a car upholstery cleaner when there is visible dirt or oil on seats. "Bacteria like to cling onto dirt and oil. Dirt particles you can see can hide millions of bacteria," says Reynolds.
Because dirt protects germs from sanitizing spray, she says, you'll want to take your cleaning efforts up a notch when you see noticeable dirt.
- Chemical Guys Nonsense Invisible Super Cleaner ($9.97, Amazon or Walmart.com)
- Mothers Carpet & Upholstery All Fabric Cleaner ($16.20, Amazon; $18.76, Walmart.com)
6. Wash Car Seats
If you're a parent to a baby or toddler, you know how absolutely gross those car seats can get. "In our research, we've found that car seats are the most contaminated surfaces in any environment anywhere," says Reynolds. That's thanks to leaky diapers, food and mucous.
The outside padding can be taken off and tossed into the wash; read the washing instructions on your model (and make sure you know how to put it back together).
A Few More Tips
- Remember to use products that are suitable for your car's interior materials (check the back of the label!), and follow the directions.
- You might need to leave these products on to sit and do their job before wiping off.
- Open the car doors/windows when using these products, as they can be harsh to breathe in, Reynolds says.
Reynolds recommends cleaning your car about once a month. You can generally do that on your own, but if there's stubborn dirt, if the job seems too big or you want to get things really like-new, you can also consider getting it detailed at a car wash, auto detailer or your car dealer.
So, How Bad Is It Really to Never Deep Clean Your Car?
While it's generally good for your health to keep your car on the tidier side, you don't have to go crazy cleaning it. "You won't be able to completely eliminate any risk of getting sick, but you can certainly reduce it with basic hygiene practices," Reynolds says.
Those things — such as removing trash every time you leave your car, wiping down surfaces more regularly and spraying with a sanitizing spray — can serve as a good foundation for a clean car.
Deeper cleaning practices, such as shampooing upholstery, can be done on occasion. This can reduce your exposure to germs, which, in turn, reduces your risk of illness.
- Britannica: “Mucous Membrane.”
- Ergonomics: “U can't touch this! Face touching behaviour whilst driving: implications for health, hygiene and human factors”
- Biofueling: “Elucidation of bacteria found in car interiors and strategies to reduce the presence of potential pathogens”
- International Journal of Environmental Research and Public Health: “Indoor Air Pollution in Cars: An Update on Novel Insights.”
- Annals of Agricultural and Environmental Medicine: "Child car seats - a habitat for house dust mites and reservoir for harmful allergens."
Is this an emergency? If you are experiencing serious medical symptoms, please see the National Library of Medicine’s list of signs you need emergency medical attention or call 911.