Growth Energy Wednesday filed a motion in a U.S. federal appeals court to intervene in a challenge to the Environmental Protection Agency’s rule allowing year-round E15 sales.

The final rule is being challenged by the American Fuel and Petrochemical Manufacturers who filed the lawsuit on Monday.

Growth Energy CEO Emily Skor called the challenge “no surprise,” noting the industry saw similar challenges when E15 was first approved in 2011.

Skor says the oil industry “wants to inject uncertainty into the marketplace.”AFMP contends, “the plain language of the Clean Air Act does not authorize an RVP waiver expansion beyond E10.”

Year-round E15 sales were authorized through a Reid vapor pressure waiver. Under the Clean Air Act, legal challenges to EPA’s E15 rulemaking may be brought as a “petition for review” within 60 days of publication of the final rule in the Federal Register.

Interested parties such as Growth Energy may also file a motion to intervene in the petition for review to protect their interests.