REF8-S has been developed as environmentally friendly test gas for the testing of smoke detectors. REF8-S can be used in the temperature range of -20... +40 °C in dry or in humid environments. REF8-S remains measurable longer than REF8, and is used for detectors having a longer signal evaluation time. Complies with environmental laws. Protects atmosphere and ozone layer. Use only together with detector tester RE6.