An Example of How Chemical Regulation Is Misshaping Litigation and What Defendants Can Do to Rebut Government Risk Assessments at Trial

In 2016, the US Environmental Protection Agency (EPA) revised its Integrated Risk Information System (“IRIS”) risk value for ethylene oxide (EtO), a colorless, odorless gas that is used widely as a sterilizer and a critical component in a host of consumer products and industrial manufacturing. IRIS changed EtO’s inhalation unit risk from.0001 per microgram per cubic meter to.003 per microgram per cubic meter – a 30-fold increase in so-called cancer potency, resulting in the premise that exposures to as low as 1 part per trillion (ppt) increase the risk of cancer. This revised value estimates a much higher cancer incidence at much lower exposure levels by orders of magnitude from the original value, and this new value has generated significant controversy.