Recently, the International Agency for Research on Cancer (IARC) classified diesel engine exhaust as carcinogenic to humans.  The IARC which is part of the World Health Organization (WHO) determined that there was sufficient evidence that exposure to diesel fumes causes lung cancer.  A positive association between diesel fumes and an increased risk of bladder cancer was also found. 

This finding does not come as a great shock since the IARC classified diesel exhaust as “probably carcinogenic to humans” about 24 years ago.  Since then increasing environmental concerns have lead to regulatory action in the developed world resulting in tighter emissions standards.  Advancements in technology have resulted in decreases in sulfur content, engines that burn diesel more efficiently and better exhaust control.  Exposure to toxic tort liability for companies that utilize advanced equipment should be limited compared to those companies that continue to use diesel fuel in older equipment.  For companies that have used and/or continue to use older equipment this finding should be considered as part of a risk assessment into liability exposure.  Risk assessments aimed at determining the level of exposure employees or others may have to diesel exhaust could help limit potential liabilities in the future.  Understanding of applicable legal standards and strategies to combat the IARC findings is critical to such an assessment.    

For example, in New York, pursuant to Parker v. Mobil Oil, just because there is no dispute that a substance is a known carcinogen does not mean plaintiffs have automatically overcome the Frye standard.  The epidemiology of any conclusion that a specific diesel fuel causes any form of cancer must be challenged.  Unlike asbestos which causes mesothelioma, diesel has not been associated with a cancer unique to itself.  Thus, development of alternative causes will be critical to defending any toxic tort claims arising from diesel fume exposure.    

In addition to companies that use diesel fuel and/or older engines that run on diesel, companies that produce alternative fuels should study the science behind the IARC’s finding about diesel exhaust, in order to understand why diesel fumes are carcinogenic and avoid pitfalls in the future.

For more information, please contact:

• Sean T. Stadelman