In Ontario, Canada, red tags are issued by licensed gas technicians or inspectors when a gas appliance or system is deemed unsafe or non-compliant with safety standards. These tags serve as a visible warning that there is a potential hazard, and immediate action is needed to resolve the issue. Red tags are a serious indication that the gas installation or equipment poses a risk to the occupants' safety and should not be used until repairs are completed and the issue is rectified. If left unaddressed, red tags can lead to disconnection of gas services, fines, or further safety violations.