A chemical spill into West Virginia's Elk River has led to a tap water ban for up to 300,000 people, shut down bars and restaurants and led to a run on bottled water in some stores as people looked to stock up.

The only safe use for the company's water is to flush down a toilet or put out a fire, Lawrence Messina, spokesman for the state Department of Military Affairs and Public Safety announced on Twitter Thursday evening.

West Virginia Gov. Earl Ray Tomblin declared a state of emergency Thursday for nine counties and includes West Virginia American Water customers in Boone, Cabell, Clay, Jackson, Kanawha, Lincoln, Logan, Putnam, and Roane counties.

A federal disaster declaration was issued shortly after, and allows for direct federal assistance in dealing with the spill, Bill Hines of the Federal Emergency Management Agency said early Friday. It remained unclear how much of the chemical spilled into the river and at what concentration, or how long the advisory would last.

The leak, which was first reported at 11:40 a.m., came from a 48,000-gallon storage tank, Tom Aluise, a spokesman for West Virginia’s department of environmental protection, told The Los Angeles Times. “All we know is that they discovered a hole in the tank, and material was leaking,” Aluise said. “How that hole got there, we don’t know.”

The company said on its Facebook page that a chemical spill occurred along the Elk River, causing contamination within the Kanawha Valley water system.

The chemical, 4-Methylcyclohexane Methanol, is not toxic, but harmful if swallowed, according to Thomas Aluise, a spokesman for the state Department of Environmental Protection. It is used to wash coal before it goes to market.

According to a fact sheet from Fisher Scientific, the chemical is harmful if swallowed and causes eye and skin irritation and could be harmful if inhaled.

The chemical, a foaming agent used in the coal preparation process, leaked from a tank at Freedom Industries, overran a containment area and went into the river earlier Thursday. The amount that spilled wasn't immediately known, but West Virginia American Water has a treatment plant nearby and it is the company's customers who are affected.

In the capital city of Charleston, a smell similar to licorice or cough syrup was evident in the air both outdoors and in areas where it had already reached the water supply.

The West Virginia Department of Health and Human Resources told NBC affiliate WSAZ symptoms include: severe burning in throat, severe eye irritation, non-stop vomiting, trouble breathing or severe skin irritation such as skin blistering.

The West Virginia National Guard planned to mobilize at an air base at Charleston's Yeager Airport on Friday to distribute bottled drinking water to emergency services agencies in the nine counties, Department of Military Affairs and Public Safety spokesman Lawrence Messina told The Associated Press.

The Charleston Daily Mail notes that "If residents have consumed the water late Thursday afternoon and are experiencing severe symptoms -- severe burning in throat, severe eye irritation, non-stop vomiting, trouble breathing or severe skin blistering or irritation -- should call the Poison Center at 1-800-222-1222 or go to an emergency room."

"Those who consumed the water but are not experiencing symptoms most likely will not be affected."

Once word got out about the governor's declaration Thursday, customers stripped store shelves in many areas of items such as bottled water, paper cups and bowls. As many as 50 customers had lined up to buy water at a convenience store near the state Capitol in Charleston.

"It was chaos, that's what it was," cashier Danny Cardwell said.