PITTSBURGH (AP) -- The oil and gas industry is trying to ease environmental concerns by developing nontoxic fluids for the drilling process known as fracking.

But it's not clear whether the fluids will be widely embraced by drilling companies.

Fracking has made it possible to tap into energy reserves across the nation but also has raised concerns about pollution, since large volumes of water along with sand and hazardous chemicals are injected underground to free the oil and gas from rock.

CleanStim is a product by energy giant Halliburton Inc. that uses only food-grade additives. The company says it is working to reduce safety and environmental concerns for both workers and the public.

Two environmental groups say they welcome the development, but still have questions about other issues caused by drilling.