IEC 61508 is an internationally recognized standard that guarantees and proves the level of reliability of a device or system, identifying the related risks to humans, the environment and things. The probability that a device or system meets the required safety level corresponds to a SIL rating, which is an integer (from a minimum of 1 to a maximum of 4). In accordance with IEC 61508, ACTUATECH pneumatic actuators have an Safety Integrity Level of SIL3.