The distinct smell of a new car has captivated the senses of drivers for generations, a fragrance often associated with the excitement of a fresh set of wheels. “Happiness is the smell of a new car,” fictional character Don Draper once said on the TV show Mad Men.
But beneath that tantalizing scent lies a complex chemical concoction that has sparked public concern.
That New Car Smell
“New car smell” is a blend of volatile organic compounds (VOCs) that emanate from the materials used in vehicle interiors. These materials include plastics, adhesives, fabrics, and sealants, which release gases as they settle — a process known as off-gassing. VOCs such as benzene, toluene, and formaldehyde are some of the common culprits responsible for the “new car smell” — there are 50-60 different VOCs in new cars, though.
In recent years, researchers have scrutinized the potential health risks posed by prolonged exposure to these chemicals. Benzene, for instance, is a known carcinogen. And formaldehyde (also a known carcinogen) is associated with respiratory issues and skin irritation. So, the question arises: Is basking in the new car scent a health hazard? Some studies suggest so.
For instance, a 2023 study that measured VOC concentration in a brand-new SUV for 12 days found concentrations of formaldehyde exceeded safety standards by 35%. Elevated levels of benzene were seen as well.
Now, a new study reported by researchers in China from the Beijing Institute of Technology and Harvard T.H. Chan School of Public Health suggests that this concerning VOC exposure is amplified by high temperatures.
Heat fueled volatiles
With global temperatures rising due to climate change, this study is timely. Data collected from several hot summer days, with temperatures ranging from 25.3°C to 46.1°C (77.5°F to 115°F), showed high levels of formaldehyde, acetaldehyde, and hexaldehyde in the car interiors.
The Chinese national concentration limit for formaldehyde in passenger vehicle cabins is set at 100 μg/m3. However, the study found levels sometimes exceeding 200 μg/m3. Similarly, for acetaldehyde, the national limit is 50 μg/m3, but the experimental car showed levels as high as 140 μg/m3.
The study highlighted that material surface temperature is the most significant factor influencing in-cabin VOC concentrations. As temperatures rise, so does the emission of VOCs from carpets, upholstery, and other interior materials. This makes hot summer days particularly hazardous for passengers.
Exposure to these chemicals can lead to various health issues. Symptoms include headaches, eye, nose, and throat inflammation, fatigue, irritability, dry cough, lung disease, and disorientation.
To mitigate these risks, automakers and regulatory bodies need to consider stricter guidelines and better materials that emit fewer VOCs.
The researchers also developed a deep-learning model to predict the concentrations of 12 typical VOCs in car cabins. This model could be integrated into intelligent car systems to assess and control in-cabin air quality in real-time.
This study brings to light the hidden dangers of the beloved “new car smell” and urges both manufacturers and consumers to prioritize health and safety over sensory appeal.
The findings appeared in the journal PNAS Nexus.
