That distinctive “new car smell” – it’s a sensory experience that divides opinions. For many, it’s an alluring aroma, synonymous with fresh beginnings and the thrill of a new purchase. It’s that leathery, plasticky scent that hits you the moment you open the door and slide into the driver’s seat. Some find it seductive, even addictive. But for others, especially those with heightened chemical sensitivities, that same smell can be overwhelmingly unpleasant, even headache-inducing.
So, what exactly creates this iconic New Smell Car experience? As automotive repair specialists, we delve into the science behind the scents you encounter in your vehicle. The answer, as chemists would tell you, lies in a complex cocktail of volatile organic compounds, or VOCs. These are primarily alkanes and substituted benzenes, mixed with smaller amounts of aldehydes and ketones.
Nearly every interior surface of a modern vehicle, from the dashboard to the seats, is constructed from fabrics and plastics. These materials are often bound together using adhesives and sealants. The new smell car phenomenon is essentially the result of “outgassing.” This is the process where residual solvents and other chemicals escape from these materials, releasing a diverse range of VOCs into the car’s cabin. This same process isn’t unique to cars; it also occurs in new airplanes, homes, and offices.
Automakers are aware of this phenomenon and have standards to manage it. A key metric in the automotive industry is minimizing the total amount of VOCs emitted from textiles and flexible plastics to prevent the recurring fogging of interior windows. While each car manufacturer has its own internal benchmarks for total VOC levels, surprisingly, there aren’t yet any overarching government regulations specifically targeting air quality inside new vehicles.
While individual VOC components in a new smell car are likely present in concentrations too low to be immediately harmful, the cumulative effect of prolonged exposure to the entire mixture of VOCs could potentially pose health concerns over time. The good news is that the concentration of these compounds decreases significantly within just a few months after a vehicle is manufactured. Although VOC levels can spike to potentially unhealthy levels in a closed car on a hot day, the natural air exchange rate in a car is quite efficient whenever a door is opened, a window is lowered, or the air conditioning is activated.
However, the window fogging tests that automakers conduct don’t provide a detailed chemical breakdown of the air composition within new cars. Popular perception, fueled by media commentators and online discussions, often attributes the pleasant aspect of new smell car mainly to phthalate plasticizers. These are commonly used in polyvinyl chloride (PVC) and other plastics to make them flexible. However, bis(2-ethylhexyl) phthalate, a frequently used phthalate in PVC, isn’t particularly volatile. Intriguingly, the limited publicly accessible studies that have analyzed VOCs in new cars don’t typically list phthalates as major components within the overall VOC mixture.
One notable study, published in December, was conducted by Stephen K. Brown and Min Cheng from Australia’s Commonwealth Scientific & Industrial Research Organization (CSIRO). They investigated VOCs in three brand new 1998 model vehicles. Using gas chromatography/mass spectrometry, they analyzed air samples taken from the cars after they had been sealed for several hours. The cars were then re-sampled at various intervals for up to two years to track the VOC dissipation.
The CSIRO researchers identified between 30 and 40 different VOCs in the cars. The most prevalent compounds included toluene, acetone, xylenes, styrene, 1,2,4-trimethylbenzene, a range of C5 to C12 alkanes, ethylbenzene, and ethylene glycol butyl ether. Initially, the total VOC concentrations in these new cars were as high as 64 milligrams per cubic meter of air (mg/m3). Interestingly, in one car that was a few weeks older due to import delays, the initial total VOC level was considerably lower at 2.1 mg/m3. These values fall within the parts-per-million to parts-per-billion range.
For context, the CSIRO report compared these findings to indoor air quality standards. They noted that total VOC levels in the indoor air of new buildings typically range from 20 to 40 mg/m3, while established buildings generally have VOC levels below 1 mg/m3. According to the report, negative sensory effects such as headaches, drowsiness, nausea, respiratory issues, and irritation of the eyes, nose, and throat are more likely to occur at VOC concentrations exceeding approximately 10 mg/m3.
The CSIRO study revealed that total VOC concentrations in cars decrease exponentially over time, reaching around 1.5 mg/m3 after about six months. After two years, two of the cars tested had VOC levels around 0.4 mg/m3. Outdoor air measured near the cars registered approximately 0.1 mg/m3. Temperature also plays a role: as the temperature inside a car increases, so does the total VOC concentration.
The CSIRO report also highlighted that not all VOCs originate from the car’s interior materials. Compounds like benzene and others from fuel or exhaust fumes, as well as siloxanes from cleaning products, can also significantly contribute to the total VOC load inside a vehicle. To address these indoor air quality concerns more broadly, CSIRO has considered developing a “green air label.” This initiative aims to help consumers make informed choices when selecting environments – including cars, airplanes, offices, and homes – that potentially offer healthier indoor air quality. In line with this, automakers are continually working to reduce or eliminate parts that emit high levels of VOCs.
Paradoxically, these efforts to reduce VOCs have led to a curious outcome: some new smell car experiences are becoming less pronounced, or even disappearing altogether. This brings us to a twist of irony. A whole market of air freshener products specifically designed to recreate the “new car scent” has emerged, promising to keep vehicles smelling showroom-fresh indefinitely. These products, readily available at car washes and auto supply stores, are often sold as “household products” and are not required to list their ingredients. Companies contacted for information about their composition have been reluctant to disclose proprietary details.
Industry experts in fragrance manufacturing indicate that these “new car smell” air fresheners typically consist of a small amount of fragrance oil applied to a blotter card, incorporated into a gel, or diluted with water and/or alcohol. Simpler fragrances might contain only a few fragrance ingredients, commonly aldehydes, esters, and ketones.
One early fragrance designed for cars was the scent of treated leather. Tanned leather can sometimes emit a slightly unpleasant odor, so tanneries often add artificial fragrances to leather to maintain a fresh scent – think about the characteristic smell inside a shoe store. This concept apparently resonated with some automakers, who have been known to incorporate leather scents and other fragrances into vehicle interiors.
Leaving aromatherapy aside, for those who appreciate the genuine new smell car experience, it’s worth enjoying it while it lasts. From a health-conscious perspective, a practical tip from the CSIRO researchers is to ensure ample fresh air circulation within the vehicle, particularly during the first six months after purchase. Opening windows or using the ventilation system can help to dissipate VOCs and contribute to a healthier in-cabin environment.
