A chemical that leaked from a truck at the Ametek Plant in Nesquehoning caused some anxious moments on Friday, with officials worried that a major explosion might occur.

The situation was resolved without any fire or explosion, but two individuals were hospitalized with reactions from the chemical.The leak prompted a response from several fire departments, as well as officials of the U.S. Environmental Protection Agency and the Pa. Department of Environmental Protection.The Rapid Response Unit, which deals with chemical spills, was dispatched and the situation was declared under control about an hour later.Assistant Fire Chief Bob Stempa of Nesquehoning identified the chemical as maleic anhydrid which, when it mixes with water and metal, becomes acidic with harmful vapors. It also becomes flammable and explosive when combined with water and metal alloys.The truck contained 40,000 pounds (20 tons) of the substance. The chemical was shipped to Ametek, a plastics division of the global company, from China, according to Stempa. He said the container arrived in New Jersey yesterday and then was transported by truck to the Nesquehoning plant.The incident began at about 10 a.m. and wasn't declared under control until about 3 p.m. Rain began falling around noon, which Stempa said could have increased the chance of an explosion.When the doors of the vehicle were opened at the loading dock of Ametek, the leak was discovered.Initially, all departments of the Nesquehoning Fire Company were dispatched to the scene.Mutual aid was quickly summoned from other departments, especially those which have foam units.Responding were volunteers from fire departments in Mahoning Township, Lehighton, Bowmanstown, Penn Forest Township, and Summit Hill.Also present was Mark Nalesnik, director of the Carbon County Emergency Management Agency.The Ametek plant was evacuated and employees were instructed to leave the premises because of the volatility of the chemical. A Kovatch Corporation plant, next to Ametek, was also evacuated. The Kovatch employees were utilized at other plants.At one point, the evacuation of nearby homes was discussed, but this did not occur.Route 54 remained open. The tracks of the Reading and Northern Railroad also were kept open. Rails go through Ametek's property.Stempa said trains were instructed to slow down out of concern that vibrations could cause problems with the chemical.Mayor Tony Walck of Nesquehoning said the evacuation of the two plants followed protocol for such a situation. He served as a volunteer fire policeman at the scene and was utilized at the entrance to the plant.Maleic anhydrid is reportedly used as a co-monomer for unsaturated polyester resins.