IEC 61508 is an international standard for functional safety of electrical, electronic, and programmable electronic safety-related systems. It provides a framework for safety lifecycle and defines requirements for safety integrity levels (SIL).
The standard applies to all industries and serves as the foundation for sector-specific standards. Key concepts include Safety Integrity Level (SIL) as a quantitative measure of safety performance, Safety Lifecycle as a systematic approach to safety management, Risk Assessment for evaluation of hazards and risks, and Functional Safety as part of overall safety dependent on correct functioning.
SIL levels range from SIL 1 (low risk reduction) to SIL 4 (very high risk reduction). Each level represents a specific probability of failure on demand (PFD) range and risk reduction factor, providing a standardized approach to safety system design.
For F&G control systems, IEC 61508 certification ensures reliability and safety, is required for worker protection, and is critical for asset protection in hazardous environments. F&G systems should be SIL-certified to meet international safety requirements.
The relationship to other standards is important: IEC 61511 is the process industry sector implementation of IEC 61508, and IEC 61508 serves as the foundation for F&G system certification, ensuring a systematic safety approach across all industries.