A large hydrochloric acid spill early Saturday at an east-central Ohio plant that makes chemical additives spawned a massive vapor cloud that took hours to dissipate, officials said. No injuries were reported.

More than 27,000 gallons of hydrochloric acid leaked from a storage tank into a retention basin at Dover Chemical Corporation around 12:30 a.m. Saturday, Dover Fire Chief Brooks Ross said. The leak was contained onsite, but a vapor cloud developed and lingered for more than five hours after the leak was discovered, Ross said.

"It was a large spill," the chief said, "and it was a huge vapor cloud that covered a large area."

Ross said it was fortunate the leak occurred overnight because the company is located near heavily traveled Interstate 77, and the area is heavily populated.

The company pumped the spilled hydrochloric acid out of a diked area into tankers and other tanks to limit vaporizing, Dover Chemical vice president of operations Tom Freeman said. Firefighters used a vapor suppressant foam to help trap any vapors, the company said.

Police and fire officials described the cloud as a minor irritant. Five hours after the leak, Ross said the cloud was limited to the spill site.

There were no evacuations, and police said residents in the area received a reverse 911 call telling them to keep doors and windows closed.

"What occurred is not acceptable, and we are very sorry this happened," Freeman said in a statement. "We will also do a thorough investigation of why the leak occurred and will put appropriate corrective actions in place to prevent reoccurrence."

Dover Chemical, located about 45 minutes south of Akron, is a subsidiary of New York-based ICC Industries Inc.