Non-Electrical Explosion Protection – Why You Should Take It Seriously

When it comes to explosion protection, many people first think of electrical devices: motors, sensors, or controllers used in potentially explosive environments. However, an equally important area often receives less attention – non-electrical explosion protection. This concerns devices and systems such as mixers, conveyors, or pneumatic assemblies that operate without electricity but can still become sources of ignition.

Non-electrical explosion protection includes all measures for mechanical devices or assemblies aimed at preventing the occurrence of an explosion. A key measure is the avoidance of ignition sources. While this may sound straightforward, in practice it is highly complex. These devices can generate potential ignition sources through friction, impact, overheating, or electrostatic charging.

For manufacturers, this means that a comprehensive ignition hazard assessment must be conducted during product development. Potential ignition sources are identified and either eliminated or reduced to a safe level. For operators, this means monitoring these devices in operation, performing regular maintenance, and consistently following the instructions in the operating manuals.

In Europe, the ATEX Directive (2014/34/EU) is the governing regulation. It defines which products require mandatory explosion protection. The decisive factor is the presence of a potential ignition source – this applies to both electrical and non-electrical devices.

For example, pneumatic hoses or fittings without their own ignition source do not require explosion protection certification. However, if electrostatic charging could occur due to their use in an assembly, this risk must be assessed through an ignition hazard evaluation of the assembly.

Since 2016, ISO 80079-36 has provided the international basis for non-electrical explosion protection. It describes the fundamental requirements and methods for ignition hazard assessment. ISO 80079-37 complements this by defining specific protection methods for non-electrical devices, such as design safety or ignition source monitoring.

For certification under ATEX Directive 2014/34/EU, electrical devices in equipment categories 1 and 2 require type examination by notified bodies. The process for non-electrical explosion protection devices is more nuanced:

• Category 3: Manufacturers may carry out the conformity assessment according to ATEX 2014/34/EU independently and issue the declaration of conformity themselves.
• Category 2: Manufacturers may carry out the conformity assessment independently and issue the declaration of conformity, but must submit the technical documentation to a notified body.
• Category 1: Type examination by a notified body is mandatory.

For international markets, the IECEx system comes into play. It is based on international standards and simplifies certification outside Europe, as test reports can serve as the basis for national approvals.

For operators of potentially explosive plants with non-electrical explosion-protected devices, responsibility does not end with the purchase of a certified product. They must:

• Follow operating manuals consistently
• Observe the manufacturer’s prescribed maintenance intervals to detect wear and ignition hazards early
• Maintain explosion protection documentation and inspections according to the Occupational Safety and Health Ordinance
• Monitor interfaces between different devices

If operators develop devices for their own use, they are legally considered manufacturers and must comply with all ATEX requirements.

Non-electrical explosion protection is not a peripheral issue but a central part of plant safety. Manufacturers must address it early in development, and operators must implement it during operation. The ignition hazard assessment conducted by the manufacturer is at the core – it requires expertise, experience, and diligence.

Given the high complexity, regular training and further education are essential to stay up to date with the latest technology and standards. Only then can safety, compliance, and cost-effectiveness be aligned.