Two ATEX directives
Two ATEX directives apply in the EU (from the French “ATmosphères EXplosibles”):
- Directive 2014/34/EU – for manufacturers. It sets requirements for equipment and protective systems intended for use in explosive atmospheres. It has applied since 20 April 2016 and replaced Directive 94/9/EC.
- Directive 1999/92/EC – for employers and users. It requires them to assess explosion risk, divide sites into zones and select suitable equipment for them.
The European Commission publishes detailed guidelines on Directive 2014/34/EU. The current, sixth edition dates from January 2026.
Hazardous zones
Zones are defined by the site operator, e.g. a refinery or terminal, depending on how often and how long an explosive atmosphere is present:
| Gases, vapours, mists | Dusts | When an explosive atmosphere is present | Required equipment category |
|---|---|---|---|
| Zone 0 | Zone 20 | continuously, for long periods or frequently | 1 |
| Zone 1 | Zone 21 | occasionally, in normal operation | 1 or 2 |
| Zone 2 | Zone 22 | rarely and briefly, not in normal operation | 1, 2 or 3 |
Category 1 provides a very high level of protection – the device stays safe even with two independent faults. Category 2 provides a high level of protection, including under common faults, and category 3 a normal level of protection in normal operation.
How to read an ATEX marking
Example: II 2G Ex ib IIC T4 Gb
- II – equipment group: II is surface industry, I is underground mining.
- 2G – category 2, gas atmosphere (G); D stands for dust.
- Ex ib – type of protection: “i” is intrinsic safety; others include “d” (flameproof enclosure), “e” (increased safety) and “m” (encapsulation).
- IIC – gas group: IIA (e.g. propane), IIB (e.g. ethylene), IIC (hydrogen, acetylene) – the most demanding.
- T4 – temperature class: maximum surface temperature 135 °C. The scale runs from T1 (450 °C) to T6 (85 °C).
- Gb – equipment protection level; Gb typically corresponds to zone 1.
Always check the marking against the certificate and the manufacturer's instructions – they also state limits such as the permitted ambient temperature.
Does a tanker tracker need ATEX?
Not always – which surprises many companies. According to the Commission's guidelines (§ 234), vehicles carrying dangerous goods fall under the ADR rules (Directives 2008/68/EC and 98/91/EC), not the ATEX Directive. If a tanker runs on public roads and an explosive atmosphere only occurs temporarily during loading and unloading, the ATEX exclusion covers the whole vehicle with all its equipment – the guidelines explicitly name vehicle tracking systems.
Things change when a vehicle or device is meant to work inside a designated hazardous zone. The guidelines note that the operator of a site, e.g. a terminal with a zone 1, may require the carrier to use ATEX-compliant products. In practice, refineries, fuel depots and chemical plants often put this requirement in their contracts.
When to choose an ATEX seal or padlock
- you secure hatches and valves of tankers carrying fuel, gas or chemicals that enter Ex zones,
- you monitor tanks, containers or cabinets at a refinery, terminal or chemical plant,
- your customer or the site operator requires ATEX in the contract.
STARCONT's ATEX-certified devices include the AT10H, G-360N and G-508N seals and the G-300N padlock. Before ordering a device for a specific zone, compare its marking with the category required there – ask us for the certificate of the chosen model. More on the differences between seals in Electronic vs mechanical seals.