There has been much industry debate over the categorization of Fire and Gas Systems (FGS) as Safety Instrumented Systems (SIS), especially as the concept of functional safety matures in the marketplace and compliance to IEC 61508 / 61511 standards is more prevalent. Fire and gas detection products and technologies are fundamentally different from other forms of instrumentation in a plant. Incorrect detector placement and poor environmental conditions can prevent the product from detecting a hazardous gas leak or flame, even when the unit is functioning properly. When a safety hazard is undetected, then the appropriate safety action (shut down, deluge, venting, etc.) cannot be initiated. Because of this, many end-users and system integrators are wondering if the functional safety standards are applicable to a FGS.