Until the introduction of the PTIR, ionisation technology was the most responsive and stable detector available for the rapid detection of fast flaming fires; however, it contains small amounts of radioactive material, so manufacturing, transport and end of life disposal costs have rightly increased in response to environmental concerns. Indeed, many countries now forbid their use completely and the great majority will only approve their use when an effective alternative is not available.

PTIR consists of independent photoelectric, thermal and infrared sensors, managed and controlled by sophisticated algorithms running on an embedded processor. The addition of the IR sensor to the established photo-thermal multi-sensor design increases the unit's performance to the point where it can be used to replace the environmentally unfriendly ionisation detector without degradation in speed of response or increased false alarm frequency.

PTIR, in common with all System Sensor devices, is an environmentally friendly detector, meeting the WEEE and RoHS legislative requirements even though they are not mandatory in the fixed installation fire industry. By not using any environmentally hazardous materials, the widespread adoption of the PTIR as a high performance replacement for the ionisation detector will immediately reduce the amount of hazardous material contaminating an increasingly fragile world.