WESTBROOK – Officials on Monday were seeking the cause of a chemical spill at a pool supply business in Westbrook.

Two employees who were working Sunday evening at NAMCO Pool and Patio were taken to a hospital as a precaution. Officials said the two spilled a mix of chemicals in a back room of the business, but it’s unclear how the accident happened.

John True of the Presumpscot Valley Hazardous Materials Unit said officials sealed the building and were working to eliminate vapors and clean up the spilled chemicals.

The chemicals included sodium sulfate, boric acid and chlorine.