Check
Choose the substance and the zone, then enter the EPL, gas group and temperature class from the label. The check runs in your browser; nothing is sent anywhere.
| Check | Equipment | Required | Result |
|---|
Three checks
- EPL and zone. Zone 0 needs Ga; zone 1 Ga or Gb; zone 2 Ga, Gb or Gc. The ATEX categories 1G, 2G and 3G correspond to them.
- Gas group. IIA equipment is for IIA substances only; IIB equipment for IIB and IIA. IIC and undivided II may be used for all groups. IIB + H2 adds hydrogen to IIB.
- Temperature class. The maximum surface temperature of the equipment must stay below the substance's autoignition temperature (AIT). If the label gives a temperature in degrees instead of a class, that value is used.
Temperature classes
| Class | Maximum surface temperature |
|---|---|
| T1 | 450 °C |
| T2 | 300 °C |
| T3 | 200 °C |
| T4 | 135 °C |
| T5 | 100 °C |
| T6 | 85 °C |
Autoignition temperatures and required classes are in the explosive limits table.
What this check does not cover
- Specific conditions of use in the certificate (X marking) and the permitted ambient temperature range (Ta).
- Installation, cable entries, inspection and maintenance (IEC 60079-14 and IEC 60079-17).
- Dust atmospheres: dust groups (IIIA–IIIC) and temperature rules differ; the dust layer calculator helps.
- Associated apparatus in square brackets (such as [Ex ia]): these are installed outside the hazardous area.
- The zone itself: the check assumes you know it.
Where this check sits in the explosion protection document
- Equipment suitability. The document compares the marking of every item in the zone with these three checks and records the result in a table.
- Unsuitable equipment. Replacement, relocation or a measure that reduces the zone goes into the action plan: who does what, and by when?
- Zone first. This check assumes the zone is right.
Sources
- Turkish regulation on the protection of workers from explosive atmospheres, Annex 3 (zones and equipment categories)
- IEC 60079-0 (groups, temperature classes, EPL)
- IEC 60079-14 (selection and installation)
This check is for information. Decisions rest on the equipment certificate, the manufacturer's instructions and the zoning in the explosion protection document.
Frequently asked questions
Can I use T4 equipment where T3 is required?
Yes. The higher the class number, the lower the permitted surface temperature: 135 °C for T4, 200 °C for T3.
Are category 2G and EPL Gb the same?
They correspond: 1G–Ga, 2G–Gb, 3G–Gc. The ATEX marking gives the category, the IEC marking the EPL; labels usually carry both.
I do not know the zone. What now?
The zone is set in the explosion protection document from the sources of release and the ventilation. If there is no document or the zone map is outdated, that comes first.
How do I read the label?
Type the marking into the Ex marking decoder; the EPL, group and temperature class are explained one by one.