New car smell
Chemical composition 
Both the scent and what produces it vary somewhat in different kinds of cars. Most of the interior of an automobile consists of plastic held together with a number of adhesives and sealers. When the car is first manufactured, these materials are left slightly unstable, and continue to release volatile organic compounds into the air afterward (cf. outgassing or offgassing). These fumes may also come from phthalates and other plastic-softening chemicals (plasticizers) that evaporate (or outgas) over time.
In 2012, the Ecology Center, a Michigan-based nonprofit environmental organization, tested more than 200 2011- and 2012-model year vehicles for chemicals such as "bromine (associated with brominated flame retardants, or BFRs), chlorine (indicating the presence of polyvinyl chloride, or PVC and plasticizers), lead, and heavy metals that off-gas from parts such as the steering wheel, dashboard, armrests and seats" and produced a ranking table.
Scientists who have studied the chemicals released recommend keeping new cars well ventilated while driving, especially during the summer. A 1995 analysis of the air from a new Lincoln Continental found over 50 volatile organic compounds, which were identified as coming from sources such as cleaning and lubricating compounds, paint, carpeting, leather and vinyl treatments, latex glue, and gasoline and exhaust fumes. An analysis two months after the initial one found a significant reduction in the chemicals. The researchers observed that the potential toxicity of many of these compounds could pose a danger to human health.
In a paper published in 2000 by researchers at the University of Texas at Austin, total volatile organic compound levels as high as 7,500 micrograms per cubic meter were measured in one new vehicle on the first day of sampling. Concentrations decayed approximately 90% over a three-week period. Over sixty chemicals were identified inside the interiors of the four vehicles in this study.
In some instances the odor can actually result from a manufacturing defect. According to official documents of Bentley Motors (BT26), there was an "obnoxious odor" in Bentley cars for model years 1999-2002. The smell emanated from a rust inhibitor that was used by Bentley during that time.
Health hazards 
A two-year study released in 2001 by the CSIRO in Australia found several health problems associated with these chemicals. CSIRO research scientist, Dr Stephen Brown, reported anecdotal accounts of disorientation, headache, and irritation in some drivers of new cars. He measured pollutant levels in new cars that were sufficient to cause similar effects within minutes in controlled experiments by other researchers. Chemicals found in the cars included the carcinogen benzene, two other possible carcinogens cyclohexanone and styrene, and several other toxic chemicals.
A more recent study in Japan found that the volatile organic chemicals in a new minivan were over 35 times the health limit the day after its delivery. In four months they had fallen under the limit but increased again in the hot summer months, taking three years to permanently remain below the limit. The limits were set by the Japanese health ministry in response to more car owners suffering from sick building syndrome. A Daily Telegraph article on the study described the enjoyment of new car smell as "akin to glue-sniffing".
However, a 2007 study by toxicologist Jeroen Buters at the Technical University of Munich in Germany and his colleagues, published in the journal Environmental Science & Technology found little toxicity in new car odors.
"New-car sprays" are available that purportedly reproduce the smell of a new car in older vehicles using an aerosol spray.
The probable origin of this fragrance concept was before the use of plastics and related chemicals, being simply a leather scent (based around castoreum and birch tar oil) to mimic the smell of expensive leather upholstery.
With the advent of cheaper vinyl upholstery, there was an interest in perfuming this with leather notes to regain the "luxury" experience. Today few people see leather notes as characteristic of a new car, so the "new car fragrance" concept has been altered.
- Overton, Santford V., Manura, John J. "Identification Of Volatile Organic Compounds In a New Automobile". Scientific Instrument Services, Inc. Archived from the original on March 7, 2005. Retrieved July 9, 2005.
- Grabbs, James S., Corsi, Richard L., Torres, Vincent M., "Volatile Organic Compounds in New Automobiles: Screening Assessment", Journal of Environmental Engineering, Vol. 126, No. 10, October, 2000. doi:10.1061/(ASCE)0733-9372(2000)126:10(974)
- "OBNOXIOUS ODOR" A Lemon Makes
- "New car drivers exposed to toxic emissions", Commonwealth Scientific and Industrial Research Organisation, December 19, 2001.
- Clover, Charles (15 January 2003). "Enjoying the smell of a new car 'is like glue-sniffing'". The Daily Telegraph.
- Choi, Charles (6 April 2007). "That New-Car Smell? Not Toxic, Study Finds". Live Science.