Congress is again asking questions about the nation’s federal helium reserve — yep, such a thing exists — after a critical audit in April.

Sure, helium is used in balloons, and can make your voice sound funny if you inhale it. But there are so many other uses for helium.

“Computer chips and fiber optics are some big uses now,” says Tim Spisak, a senior adviser at the Bureau of Land Management, which runs the reserve. “MRI is a big use.”

The reserve was first dreamed up about a hundred years ago for the military. Today, Spisak says, private industry uses about half of the helium to cool the magnets in MRIs and purify silicon.

“It is crucial, because we have no alternative,” says Moses Chan, a professor of physics at Pennsylvania State University who uses helium in his lab. 

Chan says 20 years ago, he paid $2 for a liter of helium. Today’s price: $8. 

Martha Morton, director of research instrumentation at University of Nebraska, Lincoln, works with huge magnets and uses helium to cool them. Morton says helium production isn’t keeping up with demand. And ideally, “I would like to see at least some helium reserve just to balance out price spikes,” she says.

But Congress has told the Bureau of Land Management to get out of the helium business by 2021, selling what’s left in the reserve.