A method andor system of a breathable air safety system for civilians in a building structure in an emergency. In a circuit, a first tunable CMOS inverter, controlled by a control signal, receives a first voltage from a first circuit node and outputs a second voltage to a second circuit node. The mounting plate engages its base with an upper surface of the roof. The first phosphor particles are chosen such that the first spectrum is independent of the size of the particles. Some of the reminder methods selected between may include, for example, voice, ring, vibration, light, andor text.