Internationally recognized functional safety standards have been developed and adopted to increase equipment and process safety. The primary goal of these standards is to develop a continuous improvement approach to safety system management and enable end users to understand the safety status of their assets.
IEC 61508 and IEC/ISA 61511
The International Electrotechnical Commission (IEC) published IEC 61508, Functional safety of electrical/electronic/programmable electronic safety-related systems, as a general standard applicable to many different industries. IEC 61508 provides the core requirements for safe system design of hardware and software, and it is the framework for sector-specific standards, such as IEC 61511 (process industries), IEC 61513 (nuclear applications), and IEC 62061 (discrete manufacturing and machineries).
ANSI/ISA-84.00.01-2004, Functional Safety: Safety Instrumented Systems for the Process Industry Sector, was first issued in 1996. The series of standards have been harmonized with IEC 61511.
In 2000, the U.S. regulatory body OSHA issued a letter identifying the ISA 84 standard as “good engineering practice” for safety instrumented system design. Reaffirmed by OSHA in 2005, the guidance effectively makes the ISA 84 standard part of process safety management (PSM) requirements. Paragraph (d)(3)(ii) of the OSHA PSM standard specifies: "The employer shall document that equipment complies with recognized and generally accepted good engineering practices.”
The European standards body, CENELEC, has adopted the standard as EN 61511. Each member state in the European Union has subsequently published the standard as a national standard. As recently as a few months ago, IEC 61511 was adopted into the Canadian Electrical Code as CSA-C22.2 NO.61511:17.
Widespread adoption, however, doesn’t guarantee a safer environment. Compliance with the standard requires a focused and continuous approach to functional safety.
Contact one of our experts at the International Society of Automation (ISA) to talk about standards-based safety training for your plant: