ATEX Certification for Mobile Devices: What Engineers Need to Know About Zone 1 and Zone 21

Andreas Parr Bjørnsund — Fri, 03 Apr 2026 15:58:28 +0000

If you work in oil and gas, chemical processing, mining, or pharmaceuticals, you have probably encountered the term ATEX. It refers to a set of EU directives governing equipment used in potentially explosive atmospheres. Getting ATEX certification for electronic devices — especially smartphones — is a complex process that touches on electrical engineering, materials science, and regulatory compliance.

This article breaks down the key concepts behind ATEX certification, with a focus on what it means for mobile devices deployed in hazardous areas.

What is ATEX?

ATEX comes from the French "ATmosphères EXplosibles." It encompasses two EU directives:

Directive 2014/34/EU (ATEX Equipment Directive): Covers equipment and protective systems intended for use in explosive atmospheres.
Directive 1999/92/EC (ATEX Workplace Directive): Covers the safety and health of workers potentially at risk from explosive atmospheres.

For device manufacturers, the Equipment Directive is the one that matters. It mandates that any electrical or mechanical equipment used in classified hazardous zones must meet specific safety requirements and carry appropriate markings.

Zone Classification

Hazardous areas are classified based on the type of explosive substance and how often it is present:

Gas/Vapor Zones

Zone 0: Explosive gas atmosphere present continuously or for long periods. Equipment must be Category 1.
Zone 1: Explosive gas atmosphere likely to occur during normal operations. Equipment must be Category 2.
Zone 2: Explosive gas atmosphere not likely to occur, and if it does, only briefly. Category 3 equipment is sufficient.

Dust Zones

Zone 20: Combustible dust cloud present continuously. Category 1 required.
Zone 21: Combustible dust cloud likely during normal operations. Category 2 required.
Zone 22: Combustible dust cloud unlikely, and if present, only briefly. Category 3 sufficient.

Most industrial environments where smartphones are needed fall into Zone 1 (gas) and Zone 21 (dust). This is the sweet spot where mobile communication is needed but standard consumer electronics are prohibited.

Why Smartphones Are Difficult to Certify

Smartphones present particular challenges for ATEX certification:

Battery energy: Lithium-ion batteries store significant energy. A short circuit or thermal runaway could produce sparks or heat sufficient to ignite flammable gases.
Wireless transmissions: RF energy from cellular, Wi-Fi, and Bluetooth radios must be evaluated against ignition thresholds.
Camera flash: LED flash circuits can produce localized heating.
Touchscreen: Capacitive touchscreens carry voltage across their surface.
Rapid product cycles: New phone models release annually, each requiring fresh certification.

The traditional approach was to build purpose-built "intrinsically safe" (IS) phones from scratch. These were typically slow, outdated, and expensive. A newer approach is to design certified protective cases that limit the energy available to ignition-capable circuits while preserving full smartphone functionality.

Protection Concepts

ATEX certification uses several protection concepts. The most relevant for portable electronics:

Ex ia (Intrinsic Safety, Level a): The circuit cannot produce sufficient electrical or thermal energy to cause ignition, even with two faults. This is the gold standard for Zone 0.
Ex ib (Intrinsic Safety, Level b): Safe with one fault. Suitable for Zone 1.
Ex ic (Intrinsic Safety, Level c): Safe under normal operation. Zone 2 only.

For a smartphone case designed for Zone 1, the protection must ensure that:

Battery terminals are isolated from any conductive path that could cause sparking
The device meets temperature class requirements (typically T4: max 135°C surface temperature)
IP rating is sufficient (typically IP65 or higher for dust and water protection)

IECEx: The International Equivalent

While ATEX is an EU directive, IECEx is the international certification scheme managed by the International Electrotechnical Commission. IECEx certificates are recognized in over 30 countries including Australia, Singapore, South Korea, and across the Middle East.

For manufacturers targeting global markets, dual ATEX/IECEx certification is the standard approach. The technical requirements are largely harmonized, but testing and documentation must satisfy both schemes.

Gas and Dust Group Ratings

Equipment is further classified by the types of gas or dust it can safely operate around:

Gas Groups

IIA: Propane and similar
IIB: Ethylene and similar
IIC: Hydrogen and acetylene — the most demanding group

Dust Groups

IIIA: Combustible flyings (fibers)
IIIB: Non-conductive dust
IIIC: Conductive dust — the most demanding group

A device rated for Gas Group IIC and Dust Group IIIC can be used in virtually any industrial environment, from hydrogen processing facilities to coal mines.

Real-World Application

Companies like Xshielder are tackling this problem by designing ATEX and IECEx certified protective cases for current-generation iPhones. Their approach certifies the case itself as the protective barrier, which means users get a real smartphone (iPhone 15 Pro Max, iPhone 16 Pro Max) that is certified for Zone 1 gas and Zone 21 dust environments with IIC/IIIC group ratings.

This approach has significant advantages for industries where workers need modern mobile capabilities — high-resolution cameras for inspection documentation, LiDAR for measurements, and reliable connectivity — in areas where those devices would otherwise be banned.

What to Look For

If you are evaluating ATEX-certified mobile devices for your operation, check for:

Zone rating: Zone 1/21 is the standard for most oil and gas applications. Zone 2/22 is less restrictive and may not be accepted in many facilities.
Gas and dust groups: IIC/IIIC covers the widest range of environments.
Temperature class: T4 (135°C max) covers most applications.
IP rating: IP65 minimum for dust and water protection.
Certificate validity: Ensure the certificate covers the specific phone model you intend to use.
Notified Body: ATEX certificates must be issued by an EU Notified Body. IECEx certificates come from accredited ExCBs.

Conclusion

ATEX certification for mobile devices is a specialized but increasingly important field. As industries push for digital transformation in hazardous environments, the demand for certified smartphones will only grow. Understanding zone classifications, protection concepts, and certification schemes helps engineers make informed decisions about which devices to deploy.

For more information on ATEX-certified smartphone solutions, visit xshielder.com.

Why Intrinsic Safety Matters for Mobile Devices in Industrial Environments

Andreas Parr Bjørnsund — Sat, 28 Mar 2026 07:47:40 +0000

If you work in oil and gas, chemical processing, or pharmaceutical manufacturing, you already know that not every piece of equipment is welcome on the plant floor. Consumer electronics, including smartphones, can become ignition sources in areas where flammable gases, vapors, or dust are present.

This is where intrinsic safety (IS) certification comes in.

What Is Intrinsic Safety?

Intrinsic safety is a protection method that limits the electrical and thermal energy in a circuit so that it cannot cause ignition of a hazardous atmosphere. Unlike other protection methods that contain an explosion after it happens, IS prevents ignition in the first place.

The two main certification frameworks are:

ATEX (European Directive 2014/34/EU) - mandatory for equipment used in explosive atmospheres within the EU/EEA
IECEx (International Electrotechnical Commission) - the global equivalent, recognized in over 30 countries

Zone Classification

Hazardous areas are divided into zones based on the likelihood of an explosive atmosphere being present:

Zone	Gas/Vapor	Dust
Zone 0/20	Continuous or long periods	Continuous or long periods
Zone 1/21	Likely during normal operation	Likely during normal operation
Zone 2/22	Not likely, only briefly	Not likely, only briefly

Most industrial facilities have a mix of Zone 1 and Zone 2 areas. Zone 0 is relatively rare and typically found inside tanks or vessels.

The Mobile Device Problem

Modern industrial operations depend heavily on mobile devices for maintenance management, inspection workflows, permit-to-work systems, and real-time communication. But standard smartphones are not certified for use in hazardous areas.

The traditional solution has been purpose-built rugged devices running Android or custom firmware. These devices are typically bulky, expensive, and run outdated software. Workers carry two phones: one for personal use and one certified device for work.

A New Approach

Some manufacturers are now taking a different approach: instead of building a phone from scratch, they certify protective cases that make standard consumer phones safe for hazardous areas. Xshielder, for example, produces ATEX and IECEx Zone 1 certified cases for the iPhone Pro Max. This lets companies deploy familiar, powerful hardware while maintaining full compliance.

The advantage is clear: workers get a device they already know how to use, IT departments manage a single MDM platform, and the organization avoids the cost and complexity of maintaining a parallel device fleet.

What to Look For

When evaluating intrinsically safe mobile solutions, consider:

Certification scope - Is it Zone 1 or only Zone 2? Zone 1 certification is significantly harder to achieve but covers more areas in a typical facility.
Temperature class - Different gases ignite at different temperatures. T4 (135C max surface temp) covers most common gases.
Gas group - IIC covers hydrogen and is the most stringent. IIB covers ethylene. IIA covers propane.
Software updates - Can the device receive OS updates without recertification?
MDM compatibility - Can it integrate with your existing mobile device management platform?

The Bottom Line

Intrinsic safety certification exists to protect workers and facilities. As industrial operations become more digitized, the demand for certified mobile devices will only grow. The good news is that the technology is evolving fast, and workers no longer have to choose between safety compliance and a good user experience.

DEV Community: Andreas Parr Bjørnsund

ATEX Certification for Mobile Devices: What Engineers Need to Know About Zone 1 and Zone 21

What is ATEX?

Zone Classification

Gas/Vapor Zones

Dust Zones

Why Smartphones Are Difficult to Certify

Protection Concepts

IECEx: The International Equivalent

Gas and Dust Group Ratings

Gas Groups

Dust Groups

Real-World Application

What to Look For

Conclusion

Why Intrinsic Safety Matters for Mobile Devices in Industrial Environments

What Is Intrinsic Safety?

Zone Classification

The Mobile Device Problem

A New Approach

What to Look For

The Bottom Line

Further Reading