April 12, 2023

expert reaction to study looking at volatile organic compounds in a vehicle (including those chemicals associated with ‘new car smell’) and surface temperature of materials in the car

A study published in Cell Reports Physical Science looks at volatile organic compounds in a vehicle cabin environment.

Prof Oliver Jones, Professor of Chemistry, RMIT University in Melbourne, Australia, said:

“This is a detailed study that seems to have been conducted thoroughly, in a real-world environment rather than a lab.  The authors built a predictive model of the release of the chemicals that cause new car smell and then tested the predictions against measured concentrations.

“Many of us like new car smell (myself included).  This study doesn’t look at health effects of these chemicals, but we know from previous research that some of these chemicals aren’t really good for us.

“New car smell is the result of a chemical process called off-gassing.  The term doesn’t sound appealing, but it just means the airborne release of a chemical or chemicals as a vapour, in this case from materials such as plastics and adhesives in the car’s interior.  Such chemicals can include acetaldehyde, benzene, formaldehyde, hexanal, and styrene.  Many of these compounds are listed as carcinogenic (cancer-causing), but then so are sunlight and alcohol.  It is the dose that makes the poison – just because something is present does not automatically mean it’s a problem; it’s about quantity (even water is toxic if you drink enough of it).  The current paper is focused on ways to better model how much of the chemicals that cause new car smell might be released over time in a car under different conditions.

“That said, new car smell is not without risks – we know from previous research that for some people it can cause health problems such as dizziness, nausea, and shortness of breath.  Healthwise the best new-car smell is probably no smell.

“The fact that higher temperatures increase the rate of off-gassing from materials is not new but what is interesting here is that the authors use the surface temperature of the materials to predict the amount of compound that might be released over time rather than the more commonly used metric of air temperature in the cabin.  This makes sense when you think about how hot the seats and the steering wheel can get on a hot summer day, especially in places like Australia.  A more accurate model gives us a better idea of the likely levels of potentially harmful chemicals over time and this gives us a better idea of the risks – which can only be a good thing for drivers.”

‘Observation, prediction, and risk assessment of volatile organic compounds in a vehicle cabin environment’ by Haimei Wang et al. was published in Cell Reports Physical Science at 16:00 UK time on Wednesday 12 April 2023.

DOI: 10.1016/j.xcrp.2023.101375

Declared interests

Prof Oliver Jones: “I have no conflicts of interest to declare.”