The chemical spill that left 300,000 West Virginia residents without usable water involved more chemicals than the company responsible had previously reported, officials revealed this week, leading the state’s Department of Environmental Protection to order that company to give a full accounting of the chemicals that had leaked into the Elk River.

The newly disclosed chemical appears to be somewhat less toxic than MCHM, the chemical initially identified, and it made up only a small part of the Jan. 9 spill. But the late disclosure outraged officials and citizens who had been hungry for reliable information.

“It is very disturbing that we are just now finding out about this new chemical, almost two weeks after the leak,” said West Virginia’s secretary of state, Natalie E. Tennant, in a statement on Wednesday. She called for the Centers for Disease Control and Prevention to post its water test results online. “We must have confidence that the water coming out of our faucets is not going to make our families sick.”

The owner of the storage tank where the leak occurred, Freedom Industries, initially said it had released crude MCHM — or 4-methylcyclohexane methanol, a toxic blend of coal cleaners — in the spill. But on Tuesday, the company revealed that the tank, which leaked about 7,500 gallons into the ground by the Elk River, had also contained a mixture of glycol ethers known as PPH, with a similar function as MCHM.