On Friday October 23rd at 2200 Station 37 was dispatched to 450 Amwell Road for an activated alarm. Assistant 37 arrived on scene, noticed a haze in the building, and upgraded the call to a district response. Chief 36 arrived on scene, took operations, performed a 360, and reported a water gong alarm sounding on the Charlie side of the building. Engines 36 and 37 arrived on scene with crews heading interior to investigate. A thorough search was performed on divisions 1 and 2 with negative findings for both occupants and fire. The haze was determined to be the result of a discharged dry chemical fire extinguisher. Crews set up fans and vented the structure. All units cleared the scene and command was terminated at approximately 2330.