What causes 'new car smell'?


The 2015 Ford Mustang 50-Year Limited Edition interior in Wimbledon White and black leather with contrasting cashmere accents and stitching — and probably a bunch of VOCs, too.
The 2015 Ford Mustang 50-Year Limited Edition interior in Wimbledon White and black leather with contrasting cashmere accents and stitching — and probably a bunch of VOCs, too.
(Courtesy of the Ford Motor Company)

There is nothing like new car smell. You probably wouldn't call it a fresh smell, but it's definitely an unused smell. No one else's funk has permeated the car; it's a blank slate for you and your very own funk. It smells like money — maybe like your first real job, or a graduation present, or a reward for your retirement. It might smell a bit like leather if you're fancy, or it might smell more like vinyl (before the kids have spilled who-knows-what on its easy-to-clean surface). Either way, it smells like you made a decision and committed the cash to paying for it over the next few years.

All of this is lovely, but what actually is new car smell? The truth is it's a far less romantic, yet still heady, mix of 50 to 60 volatile organic compounds, or VOCs, off-gassing in your car. (These are the same compounds that cause a greasy film to form on your car's windshield.) At new-car concentrations, these chemicals are not terribly dangerous, but they're not exactly aromatherapy, either. They do break down quickly, to the tune of about 20 percent decay every week, so the smell doesn't linger all that long. That's why we call it new-car smell, not car-I've-had-for-five-years smell.

As much as we love new-car smell, auto manufacturers are working to eliminate it. Not that they don't like the smell, but they'd rather not use the chemicals involved in the smell if they can help it. Automotive materials that include fewer VOCs, like soy-based foam seats cushions, don't off-gas quite so much, and they don't really have a smell. In fact, there may come a time when new-car smell is only available in a bottle. And if you're into that kind of thing, rest easy knowing that fragrance manufacturers aren't bottling up semi-dangerous VOCs. They're faking it, which is probably a good thing.

That's the easy answer to the question. Super nerds may proceed to the next page, where we'll look at each of the VOCs that cause new car small in more detail.

The 5 VOCs That Make Up Most of That Smell

New-car VOCs break down quickly — at a rate of about 20 percent decay every week, so the smell doesn't linger all that long.
New-car VOCs break down quickly — at a rate of about 20 percent decay every week, so the smell doesn't linger all that long.
(drbimages/E+/Getty Images)

Though there are dozens of chemicals that contribute to new-car smell, and that chemical cocktail varies by manufacturer, there are five common VOCs that make up most of the off-gassing found in the interiors of new cars:

Toluene: This liquid solvent comes from crude oil, though you probably know it best for its starring role in many nail polish removers. It's used in paints and glues, which can show up in a car's interior. It's also an anti-knock agent in gasoline, and it shows up in a car's exhaust.

Ethylbenzene: This is also a solvent, but it's a colorless, flammable gas. It's found in coal tar and petroleum, so it's probably not a surprise that it smells like gasoline. It's used in paint, but it's also used to create styrene (next on the list). Once it's off-gassed into the air, it breaks down into other (presumably less smelly) chemicals within three days.

Styrene: You won't find vast styrene deposits in nature — it's a synthetic chemical created in a lab (though there are small amounts of it in foods, including fruits and veggies). It's used in so many materials that will likely end up in your car, like rubber, insulation and carpet backing, that billions of pounds of the stuff are produced each year. It breaks down in the air within a day or two of being released in the off-gassing process.

Xylenes: This sweet-smelling, very flammable liquid is found in coal tar and petroleum. It's a solvent in both the rubber and leather industries, which is how it ends up in the new-car-smell mix. It's also one of the top 30 chemicals produced in the United States, so it's not surprising that it makes this top-five list of VOCs in your car.

Trimethylbenzene: This guy is an "aromatic hydrocarbon," though Toxipedia.org notes that it has a "strong, peculiar odor." It's a liquid used in solvents and thinners, as well as an additive in auto fuel. It breaks down in sunlight, so maybe parking in a sunny spot for a couple of days will help clear it out quicker.

If none of this seems appealing (and really, how could it?), just open your windows. Getting fresh air in the cabin of your car will clear out these VOCs more quickly and speed up the breakdown process for most of them.

Author's Note: What causes 'new car smell'?

As an automotive journalist, I've driven a lot of cars over the years. I'm often asked which is my favorite car, but no one ever asks me which is the best smelling car. I will tell you right now: any Aston Martin. I prefer the smell of their leather-and-wood interiors over any other. There's something of a British club smell about the thing, though I'm probably projecting that. There are plenty of luxury car makers who use lovely leathers, but Aston's are my personal favorite, smell-wise.

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Sources

  • Agency for Toxic Substances and Disease Registry. "Ethylbenzene." CDC.gov. Aug. 27, 2014. (Jan. 4, 2015) http://www.atsdr.cdc.gov/toxfaqs/tf.asp?id=382&tid=66
  • Agency for Toxic Substances and Disease Registry. "Styrene." CDC.gov. Mar. 3, 2011. (Jan. 4, 2015) http://www.atsdr.cdc.gov/substances/toxsubstance.asp?toxid=74
  • Agency for Toxic Substances and Disease Registry. "Toluene." CDC.gov. Mar. 28, 2015. (Jan. 4, 2015) http://www.atsdr.cdc.gov/toxfaqs/tf.asp?id=420&tid=74
  • Agency for Toxic Substances and Disease Registry. "Xylenes." CDC.gov. Mar. 18, 2014. (Jan. 4, 2015) http://www.atsdr.cdc.gov/toxfaqs/TF.asp?id=295&tid=53
  • Compound Interest. "The Chemicals Behind the 'New Car Smell.'" CompoundChem.com. June 16, 2014. (Jan. 3, 2015) http://www.compoundchem.com/2014/06/16/newcarsmell/
  • Swaby, Rachel. "What Exactly Is That New Car Smell?" Gizmodo. Mar. 27, 2012. (Jan. 3, 2015) http://gizmodo.com/5896801/what-exactly-is-that-new-car-smell
  • Thorp, Nick. "1,3,5-Trimethylbenzene." Toxipedia. July 2, 2010. (Jan. 4, 2015) http://toxipedia.org/display/toxipedia/1%2C3%2C5-Trimethylbenzene
  • Wisconsin Department of Health Services. "Toluene." Dec. 3, 2014. (Jan. 3, 2015) https://www.dhs.wisconsin.gov/chemical/toluene.htm