The Unsettling Truth Behind 'New Car Smell' Is Easily Explained By Science

Flowers, food, and new cars: the holy trinity of beloved scents. It seems strange that the interior of an automobile could bring us as much pleasure as the bounties of nature, but for many, the scent of a new car is the ultimate olfactory delight. While almost everybody has experienced "new car smell" at some point, few understand what causes it, and the truth behind the source is actually rather concerning.

New car smell is caused by volatile organic compounds (VOCs) that are involved in the manufacturing of automobile parts. In chemistry, the term "volatile" is used to refer to compounds that evaporate easily. They have very low boiling points, meaning they generally become gaseous at room temperature. VOCs are heavily present in synthetic polymers, such as plastics and rubbers. Virtually every element of a car's interior, from the fabric of the seats to the vinyl control panel to the adhesives that hold everything together, contains VOCs.

When a brand new car is assembled, all of those materials begin off-gassing. Off-gassing refers to the release of VOCs from within synthetic (man-made) materials. As VOCs leak out of the plastic, vinyl, rubber, and leather, they fill the car's interior with a characteristic scent. It's actually similar to the smell of gasoline, though much subtler, and the truth is that the appeal of new car smell is largely psychological. We associate purchasing a new car with a sense of accomplishment, and the scent comes to represent that. Unfortunately, VOCs can be harmful to your health.

Volatile organic compounds are one of the major causes of air pollution, so you certainly don't want them trapped inside your car. Numerous medical studies have linked VOCs to cancer and birth defects. Car interiors release several types of these VOCs, including formaldehyde, benzene, and toluene. Cars also contain per- and polyfluoroalkyl substances (PFAS), which are used in heat-resistant coatings that protect the interior from warping. Sometimes known as forever chemicals due to the fact that they are very slow to break down, PFAS have been found to have many harmful health effects of their own.

A 2021 study conducted by researchers at the University of California, Riverside, and published in the journal Environment International found that spending just 20 minutes in a car could expose a person to unsafe levels of formaldehyde and benzene, while the average American spends over 50 minutes a day commuting. A 2023 report published in Cell Reports Physical Science echoed these findings, this time led by researchers at Harvard and the Beijing Institute of Technology. They found that the formaldehyde levels in new car interiors exceeds Chinese national safety standards by 34.9%.

There's no way to keep VOCs out of cars to begin with, as they are so intrinsic to the manufacturing process. However, off-gassing is highest when the car is brand new, so it's a good idea to keep the windows down when you drive until that new car smell goes away.