Firefighters helped an adhesives manufacturer regain control of its workspace Thursday after a chemical reaction overheated, said Fire Chief Jack Bergeron. Bergeron said firefighters used water to cool the reaction process at Key Polymer, located at 17 Shepard St. He said that during the manufacturing process, company workers mix chemicals and then put them through a heat-producing reaction. The reactions created “too much heat in too short a period of time,” fire officials said. He said the company’s employees are not sure why the process went awry. “The reaction kind of ran away,” Bergeron said. There was no fire, although heat and smoke were present, but no injuries were reported.