Safe Ignition Sources

If an atmosphere subject to explosion cannot be prevented in a work area, secondary explosion protection is brought to bear. Secondary measures include prevention of any ignition sources in the Ex area.

However, these are not so easy to detect. Only with knowledge of what can cause a spark or heat can measures be taken to prevent explosions. The ignition sources are listed in the basic standard EN 1127-1 “Atmosphere subject to explosion – Explosion protection Part 1” as well as in the “Technical rules for operational safety” TRBS 2152, Part 3. Appropriate protective measures for preventing ignition sources are also listed there.

WAGO in Explosion Protection

Principles of Explosion Protection

Everything worth knowing about Ex protection at a single glance.

Ignition sources and their causes

Ignition sourceCause (example)
Hot surfacesHeating devices, mechanical processes due to friction and chipping, heat losses (friction coupling and braking)
Electric arcsMechanically generated sparks (e.g., due to friction, impact or machining processes), electrical sparks, electrical switch arcs
Flames and hot gasesFlames or their hot reaction products such as hot gases and glowing material particles can ignite an explosive atmosphere.
Sparks generated mechanicallyFriction, impact or machining processes such as grinding, tools such as wrenches, pliers or tools such as a ladder; work on rusty components with aluminum tools (thermite reaction)
Electrical systemsOpening and closing of electrical circuits, equalizing currents, electromagnetic fields, conductive dust
Note: Protective low voltage is not a measure to protect against explosion, since ignition is also possible with less than 50 V!
Cathode corrosion protectionReverse current to the current source, induction, short or ground faults
Static electricityStatic electric discharge
Lightening strike-
Electromagnetic fieldsFrequency ranges from 9 x 103 to 3 x 1011 Hz. These include high-frequency equipment such as radio equipment or high-frequency generators.
Electromagnetic radiationFrequency ranges from 3 x 1011 to 3 x 1015 Hz and wavelengths of 1000 to 0.1 μm. This includes optical radiation such as sunlight, lasers, lightning strikes, electric arcs.
Ionizing radiationIgnition due to energy absorption, with causes such as short-wave UV rays, X-rays or radioactive materials
UltrasoundIgnition due to energy absorption, with causes such as short-wave UV rays, X-rays or radioactive materials.
Adiabatic compression and streaming gasesDue to the high temperatures that occur due to shock waves and in instances of adiabatic compression, an atmosphere subject to explosion can ignite.
Chemical reactionDue to chemical reactions that cause heat development (exothermic reactions), materials heat up and can cause an explosion.

Read More Here

What happens during an explosion, which factors are important, and what protective measures are available? Everything you need to know about ATEX, Ex zones, ignition protection categories, etc.

Zone Classification

Depending on the type of materials that occur, hazardous locations are not equally at risk. The frequency and duration of occurrence of one of these substances give rise to the different protective requirements for operating equipment.

Ex Protection Measures

Who needs explosion protection? To whom does explosion protection apply? What must be noted here? And what is constructive explosion protection? WAGO has compiled answers to the most important questions for you.

Device Groups

Like the devices, gases, vapors, and dust are divided into various groups according to their properties. This division simplifies the right selection of devices for the various gases, vapors, and dusts.

What Is an Explosion?

Ex|plo|si|on; -s <lat.> (explosio) means "escaping under pressure." What happens during an explosion, which factors are important and what protective measures are available? You will learn everything you need to know about explosion protection right here.

Types of Protection

Only equipment protected against explosion is permitted in Ex areas. Ignition protection categories are constructive and electrical measures for equipment and qualify as secondary explosion protection.

Directives, Standards and Regulations

The requirements for electrical equipment for hazardous locations are multi-layered: National and international determinations, guidelines and standards must be complied with to achieve the highest possible level of safety. We give you an overview of the most important regulations and recommendations, such as the ATEX directive.

WAGO Products for Explosion Protection


Automation under adverse environmental conditions? WAGO products and solutions are made for this.


Connection Technology



Approved for the Ex area: WAGO products form secure connections even under the most extreme conditions


WAGO at Work

Customer Applications: Explosion Protection

As a partner and innovation leader, WAGO implements many interesting projects. Learn about the creative, efficient solutions we make possible in the process engineering area.

Aircraft Fueling and Automation

Finally failsafe: Thanks to the switch to spring pressure connection technology from WAGO, the aircraft tankers at Brazil’s airports are safer than ever before.


Automation for Pipelines

Trace heating prevents pipelines from freezing in Siberian temperatures. Explosion-protected components from WAGO play an important role.


Absolutely Reliable Quality

The requirements for the technical equipment aboard vessels are extraordinarily stringent. The WAGO I/O-System fulfills all of them.


This May Also Interest You

More from the Process Engineering Area

Whether modular process automation, explosion protection, cybersecurity or Process 4.0 – WAGO offers solutions for every challenge facing the industry.

Process 4.0

Transform and reshape processes digitally: WAGO is your reliable partner for custom development and implementation.


Modular Process Automation

Modular systems concepts are the solution to constantly shifting market demands. WAGO supports your development process.


Recommended Reading

WAGO in Other Industries

WAGO’s automation and electrical interconnection technologies are also popular beyond process engineering. Learn what solutions WAGO offers in other industries.

Marine and Offshore

Modern propulsion technology, networking subsystems – automation and digitization are standard on ships.


Power Engineering

Modern automation and digitization technologies give rise to communicative smart grids.

MM-36674  website update Energietechnik_2000x1125.jpg