Police believe an air conditioner released carbon monoxide into a Hauppauge business Wednesday afternoon, sending 17 employees to the hospital.

According to the Suffolk County Police Department, a female employee at Liqui-Mark on Davids Drive had complained of a headache and nausea. Officers from the 4th Precinct, the Hauppauge Fire Department, the Smithtown fire marshal and local ambulance personnel responded to the scene. When carbon monoxide detectors showed high levels of the gas, the HFD tested about 30 employees for exposure — 17 of whom tested positive.

The woman who first reported feeling ill was treated for non-life-threatening conditions at Good Samaritan Hospital Medical Center in West Islip, police said. The other 16 exposed employees, who felt no symptoms, were treated at Good Samaritan, Bay Shore’s Southside Hospital and St. Catherine of Sienna Medical Center in Smithtown.

Officials said an air conditioning unit is believed to have caused the high levels of carbon monoxide at the business, which will be closed until that unit is repaired. Police said additional carbon monoxide detectors are being installed at the building.

The fire marshal is still investigating.