SIL achievement requires that the design of a safety function meets three specific criteria as outlined in the standard. This section will concentrate on number 1 – Random Hardware Integrity. What is functional safety? Functional safety is the active detection of potentially dangerous conditions, resulting in a demand for a protective mechanism or function to prevent or reduce the impact of hazardous events that might occur. Forming part of the overall safety of equipment under control (EUC), functional safety has focused on electronics and related software. IEC 61508 is an international standard for “Functional Safety or electrical/electronic/programmable electronic safety-related systems”.