"Hundreds of environmental groups on Tuesday submitted a petition calling on the Environmental Protection Agency (EPA) to take action to curtail ethane and methane emissions responsible for smog.
In a statement Tuesday, the Center for Biological Diversity, one of the groups petitioning, noted that despite ethane and methane’s contributions to smog, they are exempt from emissions limits based on a 1977 understanding of their contributions.
The agency’s official definition of “volatile organic compounds” exempts some compounds by classifying them as “negligibly reactive.”"
Source: The Hill, 04/07/2021