(CNN) -- Residents of a western Pennsylvania neighborhood can return home Sunday after a chemical leak forced them to evacuate the night before.



Hundreds of residents were forced to flee Saturday after a chemical leak in Petrolia, Pennsylvania.



Authorities surveyed the neighborhood in Petrolia and determined that no traces of the toxic chemical remained, said Freda Tarbell, spokeswoman for the Pennsylvania Department of Environmental Protection.



A leak at the Indspec Chemical Corp. plant in Petrolia on Saturday formed a cloud affecting at least 2,000 residents -- some of whom fled their homes. Others huddled indoors with their windows shut, authorities said.



Three people were taken to hospitals, but officials could not immediately say why.  Watch why residents were asked to evacuate »



It was not immediately clear how many people were injured, though plant manager Dave Dorko said all employees and inspectors at the plant were safe and accounted for.



Tarbell described the chemical as fuming sulfuric acid, which is also known as oleum.



The plant uses the chemical during its production process, she said. The plant produces a chemical called Resorcinol -- essentially a strong glue used in the tire industry.



The leak affected between 2,000 and 2,500 residents, Tarbell said. Some stayed the night with friends and relatives and some sought refuge in shelters. Others opted to stay indoors and "shut their windows and doors to make sure the acid cloud was not entering their home," she said.



Ed Schrecengost, a former Indspec employee, said firefighters showed up at his son's wedding reception, urging the guests to leave.



"It's about as dangerous as you can get," Schrecengost told CNN affiliate WPXI. "It's a very fuming acid. A quart bottle of this material could fill a household in two seconds."



Dorko said the leak was caused by an overflow from a tank. The material, he said, evaporates easily, creating a toxic cloud.



CNN's Saeed Ahmed and Janet DiGiacomo contributed to this report.
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question: what was the cause for toxic cloud?, answer: chemical leak | question: Were there any traces of chemicals?, answer: no | question: Where was the chemical leak?, answer: Petrolia, Pennsylvania. | question: what was the information provided by officials about chemicals?, answer: no traces of the toxic | question: Who was taken to hospital?, answer: Three people | question: When did the Toxic cloud form?, answer: Saturday | question: Who says the area is surveyed?, answer: Authorities | question: How many residents where taken to hospital, answer: Three | question: What did officials say after surveying the area, answer: no traces of the toxic chemical remained, | question: Does the area show traces of chemical?, answer: no | question: How many residents were injured?, answer: 2,000 | question: What day did toxic clouds appear?, answer: Saturday | question: What leaked from the Pennsylvania plant, answer: a chemical | question: what Environmental official says area surveyed?, answer: Freda Tarbell,