On September 4th, 2015 at approx 2242 hours, Station 14 was alerted to Co. 10's area for a Hazmat Investigation. Engine 143 responded with 4 volunteers, Ambulance 148 with 4 volunteers, EMS Utility 14 with 1, and Paramedic Ambulance 149 with 2. While en route, Communications advised of an occupant that had mixed bleach and lysol causing a vapor cloud. Two occupants were reported to be ill. Engine 143 was first arriving and laid out at the driveway, passing command. DO1 arrived and assumed command, and E143 was assigned recon. E143 metered the house, and found all readings within normal limits. The house was ventilated and PA149 obtained one refusal of care. Units packed up and returned to service.