US shale drillers are using benzine in fracking liquids.

Bloomberg: “Some oil and gas drillers are using benzene, which can cause cancer, in the mix of water and chemicals they shoot underground to free trapped hydrocarbons from shale rock, an environmental watchdog group said today.”
“Benzene isn’t banned in hydraulic fracturing, although diesel is restricted because regulators determined it may have carcinogens, including benzene. Drillers need a permit before using diesel in the fracking mixture that’s blasted into shale with oil and gas deposits; they don’t need one for benzene. The Environmental Integrity Project today said at least six fracking fluid additives contain that compound.
“It’s bombs away. You can use benzene in large quantities, just as long as you don’t call it diesel,” said Eric Schaeffer, the Washington-based group’s executive director. Schaeffer said the compound could contaminate drinking water, although the group didn’t provide any evidence today showing such contamination.
In 2005, Congress exempted fracking from requirements of the Safe Drinking Water Act. Health advocates called it the “Halliburton loophole,” referring to Halliburton Co. (HAL), the largest provider of fracking services, led by Richard Cheney before he was elected vice president in 2000.
The law maintained the EPA’s oversight of fracking if diesel is part of the mix, in large part because the agency found that benzene and other so-called BTEX compounds in diesel pose the greatest threat to drinking water.
Representatives of drilling companies said that fracked wells haven’t leaked chemicals into the aquifer, and so the use of benzene raised by the Environmental Integrity Project shouldn’t be a worry to the public.
“The risk EIP claims to exist would only actually exist if there were examples of hydraulic fracturing contaminating groundwater. There aren’t,” Steve Everley, a spokesman for Energy in Depth, which represents companies that drill and frack, said in an e-mail. “Presence doesn’t indicate harm.”
….Studies on benzene show that it causes cancer in humans and animals, especially leukemia and other blood cancers, according to the American Cancer Society.”