Last edit: 07/08/2026
This book provides a practical guide to risk reduction in machinery through Functional Safety.
Three key international standards address this topic: ISO 13849-1, IEC 62061, and ISO 13849-2. The second edition of IEC 62061 was published in 2021, while the fourth edition of ISO 13849-1 was published in April 2023.
Almost every machine presents hazards during its lifecycle. To achieve an acceptable level of safety, appropriate risk reduction measures must therefore be implemented.
Some of these measures are inherently independent of Functional Safety. For example, a fire hazard in a forging press may be reduced by replacing hydraulic oil with a less flammable water-glycol fluid, while access to hazardous machine movements may be prevented by means of fixed guards. In both cases, risk is reduced without relying on a control system.
In many other situations, however, safety depends on the correct operation of a control system.
Consider, for example, an interlocking device used to detect the opening of a movable guard protecting access to a hazardous area. When the guard is opened, hazardous machine movements must be stopped. Similarly, a high-pressure switch may detect an excessive pressure condition and initiate the closing of a valve to bring the system to a safe state.
These are examples of safety functions. Once a safety function has been defined, a safety-related control system must be designed to perform it with an appropriate level of reliability.
This is the essence of Functional Safety.
ISO 13849 and IEC 62061 establish requirements for the design and evaluation of safety-related control systems used to reduce the risk of injury or harm to people operating, maintaining, or working in the vicinity of machinery.
Whenever risk reduction depends on a control system, an essential question arises:
How likely is it that the safety function will fail when it is required?
For example, what is the probability that a compressor will fail to stop, when excessive pressure develops in a vessel? Or that an hazardous movement inside a robot cell will continue after an access door has been opened?
Answering these questions is one of the fundamental objectives of Functional Safety.
This book explains how ISO 13849-1 and IEC 62061 follow remarkably similar principles for achieving functional safety in machinery, while also highlighting the important differences between the two approaches.
Our objective is to provide readers with a clear and practical understanding of both standards and to show how they can be applied effectively when designing and validating safety-related control systems.
It is possible to buy the book directly on the Wiley website or on your local Amazon webstore.