The Natural Resources Defense Council filed a lawsuit Tuesday against the Food and Drug Administration for its failure to act on the group’s petition to ban bisphenol A from food packaging.

BPA is a chemical used to make hard plastic and to line the cans of most food products. The advocacy group sent a petition to the FDA in 2008 asking that it ban the use of BPA in food packaging. By law, the FDA had 90 days to respond to the petition.

“And 20 months later, the FDA has not responded to that petition, so we are asking the court to intervene and require the FDA to take action,” said Sarah Janssen, a senior scientist with the council.

If the suit is successful, the court can order the FDA to respond to the petition and hold the agency in contempt of court if it fails to do so, said Aaron Colangelo, a senior attorney with defense council.

The FDA does not comment on pending lawsuits, said Michael Herndon, an agency spokesman.

The American Chemistry Council, a chemical industry lobbying group, released a public statement in response, saying it “believes that the scientific process and the public interest are both best served by allowing the FDA to complete its ongoing review of the science surrounding the safety profile of BPA.”