Functional safety in the process industry

Partner for the process industry

With groundbreaking solutions in connection and automation technology, Phoenix Contact is your key partner for superior availability in the process industry.

We offer:

  • Safe components for safety applications in process plants, certified in accordance with IEC 61508 and IEC 61511

  • ATEX-certified, robust safety technology for use in potentially explosive environments

  • Safe diagnostics and easy proof test in accordance with IEC 61508

Find out more now!
Man with safety helmet in front of process industry plant

When planning, setting up, and operating safe process plants and machines, current directives and laws provide the framework to be observed. These standards reflect the minimum state of the art of technology that is to be adhered to. The IEC 61511 series of standards governs the application of the functional safety of systems in the process industry.

The planners, manufacturers, and operators of systems are just as responsible for implementation as the system integration department that implements functional safety. Amendments to the requirements require regular adjustment to verification documents, processes, and employee training. Modifications and integration of subunits into existing systems make continuous checks necessary.


The process industry deals with a wide range of potential hazards for humans, property, and the environment. To minimize these risks, operation and regulation functions maintain the process control engineering sequences. Systems are protected with integrated safety technology systems.

Emergency shutdown (ESD) safety relays
Emergency shutdown (ESD) safety relays YouTube

Emergency shutdown (ESD) Safe shutdown if there is danger

When emergency situations occur in process plants, the protection of people and the environment has highest priority. To minimize hazards, immediate shutdown of affected systems is required, among other things. In this case, the emergency shutdown system (ESD) intervenes.

Safe coupling relays from Phoenix Contact safely switch off affected applications in an emergency.

Fire and gas (F&G) safety relays
Fire and gas (F&G) safety relays YouTube

Fire and gas Switch on warning systems at an early stage

In addition to the emergency shutdown system, the process industry also requires a fire-and-gas system. If fire occurs or explosive gases escape, early warning of danger is necessary.

Safe coupling relays from Phoenix Contact safely switch on sirens and warning lights in an emergency.

Video series
Functional safety in the process industry
What does HAZOP stand for and what is an interlock function? Manuel Ungermann, Safety Product Manager at Phoenix Contact, explains terms, topics, and products related to safe switching on and off in process engineering systems.
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Functional safety in the process industry


For functional safety applications in the process industry, Phoenix Contact offers a wide range of SIL-certified products, from safe coupling relays to safe controllers.

Standards and directives Requirements for designing protective functions in the process industry

There are special design guidelines with respect to functional safety when it comes to the fundamental requirements for safe operation of systems in the process industry. The internationally harmonized procedure for PCE safety equipment is described in IEC 61511. A significant part of this procedure is the safety lifecycle in conjunction with functional safety management. The individual phases of the procedure are highly interdependent and make it possible to bear in mind all requirements over the entire lifecycle of the safety equipment.

Safety lifecycle Information for planning, system integration, operation

Safety lifecycle for system planners
Safety lifecycle for system integrators
Safety lifecycle for system operators
Safety lifecycle for system planners

  • Safety planning
    Planning of the activities that are required for achieving functional safety (FS) of the system, including  verification and validation.

  • Risk assessment
    Systematic identification and evaluation of all risks and establishment of measures to be taken for adequate risk reduction.

  • Assigning protection layers
    Assigning the planned measures to individual protection levels and establishing the required SIL for safety functions.

  • Functional safety management
    Establishing a management system for controlling the safety lifecycle and for resource planning.

  • Evaluating functional safety
    Recurring assessment of whether the safety planning and functional safety management were applied correctly.

Safety lifecycle for system integrators

  • Specification of safety requirements
    Specification of the requirements for the safety system including the safety functions.

  • Validation planning
    Planning of the necessary activities for checking the specified safety functions.

  • Design and planning of the safety system
    Detailed planning of the implementation of the safety requirements and the safety functions, validation of the safety integrity.

  • Assembly and startup
    Installation of the safety system and commissioning.

  • Validation
    Implementation of the function test based on the validation planing and providing evidence of adequate risk reduction in accordance with the risk assessment.

Safety lifecycle for system operators

  • Operation and modification
    Maintenance of the functional safety during operation and in the event of system modifications

  • Decommissioning
    Deactivation and complete removal of safety functions that are no longer necessary