Standards

The main process safety standards are as follows:

- DIN V 19250 (Germany, 1989):  Defined the plant risk analysis method and the AK 1-8 (for hardware) requirement classes, which were certified exclusively by TÜV Germany. 
This was accepted by the global market as the only official standard for safety instrumented systems (SIS). After being adopted in IEC 61508, DIN V 19250 was withdrawn in 2004.

- ISA S84.01 (US, 1996):  For chemical plants. Many parts of ISA S84.01 were adopted in IEC 61511.

- IEC 61508 (Europe, 1999), IEC 61511 (Europe 2003)