RALEIGH (AP) — North Carolina is one of 33 states not tracking the use of a toxic firefighting foam even as the military is checking bases across the nation for potential groundwater contamination triggered by the use of the foam.

The foam was used at 664 military bases and was likely used at airports and other sites where catastrophic petroleum fires were a possibility.

The chemicals in the foam are known as perfluorinated compounds, or PFCs, which have been linked to prostate, kidney and testicular cancer, along with other illnesses.

North Carolina Department of Environmental Quality spokesman Jamie Kritzer said the agency is awaiting guidance from the Environmental Protection Agency and the Department of Defense on the issue of the foam.