EPA hydrocarbons in gasoline test results

Benzene is currently subject to a 0.62% v/v limit, per the EPA’s Mobile Source Air Toxics 2 (MSAT2) regulation. The MSAT2 limit came into force on January 1, 2011. The EPA-published test data shows conventional gasoline (especially summertime conventional gasoline) slightly above the limit, but also shows reformulated gasoline consistently below the 0.62% v/v limit.

As shown below, aromatics content of all four gasolines had shown a downward trend from 2005 through 2013 before plateauing. However, per EPA test data, the aromatics content of conventional gasoline appears to have increased significantly in 2019 and then drama