Hawaii County Civil Defense Administrator Talmadge Magno said Sunday at a news conference the Puna Geothermal Venture, a geothermal power plant, has been evacuated and an emergency shutdown procedure was conducted.

There are still nearly 50,000 gallons of pentane stored at the site, according to Hawaii News Now.

"Everything is still on property," Magno said. "They moved it to high ground just in case any flows would start coming that way, give them a little more time. But their plans are made to get them out of there if it gets to that next level."

The Puna Geothermal Venture, located near the latest volcanic eruption on Hawaii's Big Island.  (Hawaiian Electric Company)

Pentane is a clear colorless liquid with a petroleum-like odor that's a component of some fuels, and "is employed as a specialty solvent in the laboratory," according to PubChem, a public repository for information on chemical substances and their biological activities, run by the US National Institutes of Health. 

The NIH lists pentane as an "extremely flammable liquid and vapor."