“What we know scares us, and we know there’s a lot more we don’t know,” a West Virginia environmental scientist said Wednesday after revealing he had found formaldehyde in water samples taken after officials had declared the water safe for drinking.

Scott Simonton, a Marshall University environmental scientist and member of the state Environmental Quality Board, told a joint legislative committee on water resources that he found traces of formaldehyde in water samples taken from a restaurant in downtown Charleston, the Charleston Gazette reported.

“I can guarantee that citizens in this valley are, at least in some instances, breathing formaldehyde. They’re taking a hot shower. This stuff is breaking down into formaldehyde in the shower or in the water system, and they’re inhaling it.” —Scott Simonton, EQB

Though he did not say exactly when he took the sample or how much was found, Simonton’s statement comes weeks after local officials declared the water safe to drink following the spill of over 10,000 gallons of coal processing chemicals MCHM and PPH into regional water source, the Elk River.

Crude MCHM has methanol as one of its main components and methanol breaks down into formaldehyde, a known carcinogen, Simonton explained.

“We know that (crude MCHM) turns into other things, and these other things are bad,” Simonton told reporters Wednesday. “And we haven’t been looking for those other things. So we can’t say the water is safe yet. We just absolutely cannot.”