There are people who just love “that new car smell,” and why not? To many, it is a pleasant aroma that triggers happy olfactory memories of coming of age and being able to financially purchase your first car—and for some, it may bring them back to the time when they bought their first minivan as they were getting ready to start their family: nice memories! The problem is that the pleasant aroma is the result of volatile organic compound (VOC) emissions that could potentially be unhealthy for you.  As a result of that concern, many governments are enforcing more stringent regulations on the auto industry to reduce or eliminate the problem.

The European Union actually started developing regulations to address automotive in-cabin VOC emissions more than 10 years ago, and just two years ago they introduced new legislation calling for even greater emission reductions. US lawmakers are expected to follow suit and pass more restrictive emission requirements in the coming years. But, even if the US doesn’t act, auto manufacturers always build to the most stringent requirements and are working to meet the standards already implemented in the EU.

So, what causes these VOC emissions? They come from polymer additives, found in resins such as polypropylene used in the auto cabin, and the breakdown products from catalysts used in the manufacture of the resin. Auto manufacturers are using polypropylene to replace metal and other heavier weight materials in the manufacture of car interiors—in the dash, steering wheel, glove compartment, cup holders, and other areas. Polypropylene is preferred because of its life expectancy in use and its high toughness-to-weight characteristics. The EU regulations now significantly limit the number of emissions in the automobile cabin due to concerns about the effects on human health, although there is no single, definitive study that proves that a hazard to human health exists.

Fortunately, the chemical industry is helping auto manufacturers to meet this challenge. One example of this is that new advancements are being brought forward to improve the post-reactor modification of polypropylene used for making many interior and exterior automobile parts. Organic peroxides are typically used to modify the viscosity of post-reactor polypropylene to improve its processing and use characteristics.  At least one organic peroxide producer continues to develop new molecules for this application which are lower in VOC emissions than previous generation organic peroxide products.  As a result of this auto manufacturers are able to use polypropylene even more extensively within a car’s interior to reduce not only weight but also in-cabin VOC emissions.

Chemical producers and major resin manufacturers are also working together to create and implement sustainable solutions to address a growing array of regulatory challenges.  The industries continue to work together to provide solutions that can reduce fuel consumption and move towards the goal of a totally recyclable automobile. 

Some new offerings have the potential of reducing in-cabin auto emissions by up to 30 percent using current technology.  Additional future improvements seem possible!  Work will continue to be focused to further reduce emissions from polypropylene and other plastic resins used in the automobile cabin. 

In-cabin auto emissions will remain a hot-button issue for EU and US regulatory bodies.  They will continue to put pressure on automobile manufacturers to achieve further reductions. Innovation from the chemical industry is well-positioned to help automobile manufacturers meet these requirements.

Paul Iacobucci is currently Commercial Manager for Organic Peroxides at Nouryon and has worked in the chemical industry for more than 35 years. Paul has been an active member of the Organic Peroxide Producers’ Safety Division (OPPSD) of Plastics (previously the SPI) and is an industry representative on the NFPA Technical Committee of Code 400 (Hazardous Materials).  He has also been previously active in the American Institute of Chemical Engineers (AIChE).