( 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 .
NEW : Environmental official says area evacuated , no traces of chemical remain . Toxic cloud forms Saturday after chemical spill at Pennsylvania plant . Local residents taken to hospital ; cause of death not known .