⚠️ A small cause – with explosive effects
In potentially explosive areas, a single moment is often enough: a spark, a hot surface, or an electrostatic discharge. If an ignitable air-gas or air-dust mixture is present at the same time, an explosion will occur. That is why avoiding ignition sources is the be-all and end-all of explosion protection.
💥 Overview of the most common sources of ignition
Here is an excerpt of the 13 types of ignition sources according to DIN EN 1127-1, summarized in an easy-to-understand manner:
💥 Overview of the 13 ignition sources according to DIN EN 1127-1
| No. | Ignition source | Practical example | Precautionary measure |
|---|---|---|---|
| 1 | Hot surfaces | Motors, bearings, lights | Temperature monitoring, correct selection |
| 2 | Flames, hot gases | Welding work, open flames | Permit requirement, fire ban |
| 3 | Mechanically generated sparks | Grinding, hammering on metal | Spark-free tools, suitable materials |
| 4 | Electrical systems | Switching sparks, defective cables | ATEX-certified equipment, maintenance |
| 5 | Currents through direct current and high frequency | Induction heating, HF drying | Shielding, distance, suitable devices |
| 6 | Electrostatic discharge | Plastic pipes, powder silos | Grounding, antistatic equipment |
| 7 | Lightning strike | External tanks, pipe bridges | Lightning protection systems |
| 8 | Electromagnetic waves (EMW) | Radar, mobile communications, radio equipment | Distance, EMW-safe design |
| 9 | Ionizing radiation | X-ray testing equipment, radioactive sources | Shielding, labeling |
| 10 | Ultrasound | Cleaning with high-frequency sound | Check restrictions and approvals |
| 11 | Adiabatic compression | Quick-acting valves, compressors | Slow opening, pressure shock-free systems |
| 12 | Shock waves | Explosion pressure relief, gas breakthroughs | Pressure surge prevention, decoupling |
| 13 | Chemical reactions | Spontaneous combustion of oils, metal dust | Material separation, temperature control |
🧰 How can ignition sources be avoided?
DIN EN 80079-36 provides clear guidance. It is important to note that:
- Prevention of potential ignition sources through design
- Use of certified components
- Continuous maintenance and monitoring
- Employee training: Recognizing ignition sources means avoiding them
✅ Practical checklist: Avoid ignition sources
Before using a device, tool, or machine in zones 0, 1, 2, or 20, 21, 22:
☐ Is there a possibility of mechanical friction or sparking?
☐ Are there any hot surfaces or electrical components?
☐ Are materials used that can become statically charged?
☐ Is there an assessment of ignition sources in accordance with EN 1127-1 or EN ISO 80079-36?
☐ Is there an ATEX marking (if required)?
💬 Important:
An explosion is equally dangerous in every Ex zone.
The zone classification only indicates the frequency of explosive atmospheres – not the consequences of ignition. Therefore, explosion protection in Zone 2 or 22 must be taken just as seriously as in Zone 0 or 20.
🧯 Conclusion
The best explosion is the one that never happens.
Avoiding ignition sources is the first and most important step in explosion protection. If you know the typical mistakes, you can recognize risks—and prevent them with simple measures.