KOKOMO, Ind. (AP) _ The U.S. Environmental Protection Agency accuses an Indiana art glass manufacturer of violating federal clean-air standards and emitting elevated amounts of potentially toxic materials.

The EPA recently notified Kokomo Opalescent Glass that it was violating the Clean Air Act by failing to obtain a federal permit regulating glass manufacturers. The Kokomo Tribune reports that the EPA claims the violation resulted in the emission of elevated amounts of metals into the air such as cadmium, chromium and arsenic.

The Indiana Department of Environmental Management says the company holds a state permit because it emits fewer pollutants than the more stringent federal permits required for art glass factories.

But the EPA alleges that the company should be required to obtain a federal permit because of the furnaces it uses to melt glass.