- Write the zone, minimum equipment protection level, gas and dust groups, temperature class and acceptable protection concepts into the tender, not simply 'explosion proof phone'.
- Require the ambient temperature range on the certificate itself; a device rated only to plus 40 °C does not meet Gulf open-plant conditions in July.
- Every accessory that connects electrically, including headsets, cables and docks, must be covered by the certification, or the assembly no longer meets it.
- Specify camera policy, the Android patch end date and EMM enrolment in advance, because hazardous area handsets often fail on management after passing certification.
Most tenders for hazardous area handsets are lost or won before a single product is compared, in the drafting of the requirement. A specification that reads “supply 120 explosion proof phones, ATEX approved” invites four incomparable bids: a Zone 2 rugged Android, a Zone 1 feature phone, a certified tablet and a phone case. A specification that names the classification, the protection level, the management platform and the repair route produces four bids you can put in a table.
This is a working intrinsically safe smartphone specification checklist, written to be lifted into a tender document and edited. Each section explains what the clause is for, because the reasoning is what you will need in the clarification meeting.
1. Start with the area, not the device
Everything downstream depends on the hazardous area classification, and the classification belongs to you, not to the supplier. Pull the current classification drawings and the schedule behind them, walk the routes your users actually take, and record the most onerous case on each route rather than the typical one. A portable device has to be selected for the worst place it will be carried.
Clauses to write:
- The device shall be suitable for gas zone [Zone 1] and dust zone [Zone 21], classified under IEC 60079-10-1 and IEC 60079-10-2. Where the site is classified to NFPA 70, the device shall be suitable for [Class I, Division 1, Groups C and D].
- Minimum equipment protection level [Gb] for gas and [Db] for dust. Devices marked Gc or Dc only shall not be offered.
- Gas group [IIC]. Dust group [IIIC].
- Temperature class [T4] or better.
- Certified ambient temperature range shall cover [minus 20 °C to plus 55 °C] and shall be stated on the certificate, not only in marketing material.
- Acceptable protection concepts: intrinsic safety to IEC 60079-11 at level [ia or ib]. Increased safety at level ec, non-sparking nA and restricted breathing nR are not acceptable for this area.
The ambient range clause earns its place more often than people expect. A device certified to plus 40 °C is not compliant on open plant in the Gulf in July, and a device certified to minus 10 °C is not compliant on a northern winter shift. The certificate limit is the limit.
2. Certification and market access
Name the schemes you will accept and the evidence you expect, and require it before award rather than on delivery.
- A current IECEx Certificate of Conformity covering the exact model and variant offered.
- For equipment placed on the European market, an ATEX EU-type examination certificate from a named notified body, together with the EU declaration of conformity. For Great Britain, either the UKCA route or CE under the current recognition arrangements.
- For sites under NFPA 70, listing for the classified location by a nationally recognised testing laboratory.
- Radio approvals for every country of use: Radio Equipment Directive conformity in the EU, the equivalent UK regulations, an FCC identifier in the United States, and national type approval elsewhere.
- Any national conformity instrument required for import, for example the SASO and SABER route in Saudi Arabia or PESO approval in India.
Explosion protection and radio compliance are separate tracks. A device can hold a faultless Ex certificate and still be illegal to switch on in your country. Ask for both.
3. Ingress, drop and the physical environment
This is where marketing shorthand does the most damage, because the two headline claims on every rugged datasheet mean less than they appear to.
IP ratings. IP68 is declared under IEC 60529, and for the 8 digit the test conditions are agreed between manufacturer and user rather than fixed by the standard. So IP68 alone tells you very little. Ask for the declared immersion depth and duration, and put a minimum in the specification.
Environmental and drop testing. A rugged or drop-tested claim is not a certificate, and there is no pass or fail stamp to hold. A device described this way is claiming that some test methods were run at some profiles. Ask which methods, at which levels, and for the report. Drop height, drop surface and number of drops are the numbers that decide whether a handset survives a grating.
Clauses to write:
- Minimum ingress protection IP68 to IEC 60529, with declared immersion depth of at least [1.5 m] for at least [30 minutes].
- Environmental and drop test methods and profiles to be stated, with the drop test method, drop height, impact surface and number of drops declared, and the test report available on request.
- Display shall be operable with [nitrile and leather rigger] gloves and legible in direct sunlight; state the measured display brightness.
- Chemical resistance to the substances handled on site, where the housing materials are likely to be exposed.
4. Battery, charging and endurance
Battery clauses do double duty: they cover the shift, and they cover a compliance obligation most buyers discover late.
An intrinsically safe device is certified with specific cell types, identified in the certificate schedule. Substituting a visually identical cell invalidates the certification. In almost every case the certificate also carries a condition that charging must take place outside the hazardous area, and often that the battery may only be changed outside it. Those conditions have to reach the people carrying the device, through the site operating procedure and the toolbox talk, not just the filing cabinet.
- Battery capacity sufficient for a [12 hour] shift with [the site profile: continuous PTT, periodic camera use, GNSS on], with the assumed usage profile stated.
- State whether the battery is user replaceable, and where. Confirm in writing whether battery exchange in a classified area is permitted by the certificate.
- Only cell types listed in the certificate schedule shall be supplied as spares; supply the part numbers.
- Charging equipment shall be identified, and its location requirement stated. Multi-bay chargers for a non-hazardous charging room shall be quoted as an option.
- UN 38.3 test summary and the applicable transport classification for the cells to be provided.
- Battery replacement policy over the device lifetime, including availability of spares for at least [5 years] after last shipment.
5. Camera policy
A 50 MP camera is the single most useful feature on a field handset and the single most likely reason your specification gets rejected by a site security review. Decide the policy before the tender, not after.
Realistic options, in rough order of how often they are chosen:
- Camera present, disabled centrally by device management, enabled by exception under a photography permit.
- Camera present and enabled, with geofenced or application-level restriction.
- Camera present, restricted to an approved inspection or permit application which stores images inside the corporate system and blocks the gallery.
- Camera-free variant for sites where any imaging device is prohibited.
Write the chosen option into the specification along with the mechanism, because “the camera can be turned off” is true of nearly every phone and tells your security reviewer nothing. What they need to know is whether it can be turned off in a way the user cannot reverse.
6. Operating system and device management
Hazardous area handsets are estate devices. They fail on management long after they have passed on certification.
- Android version at delivery, and the committed horizon for operating system upgrades and monthly or quarterly security patches. State the end date, not a promise of “regular updates”.
- Enterprise mobility management support: the device shall enrol into [your EMM or MDM platform] in fully managed mode, with a work profile where required.
- Zero-touch or equivalent bulk enrolment, so devices arrive provisioned rather than being configured one at a time.
- Application allowlisting, kiosk or dedicated-device mode, and remote wipe.
- Hardware controls that can be policy-managed: camera, microphone, USB data, Bluetooth, tethering, GNSS.
- Certificate-based Wi-Fi and VPN enrolment for site network access.
If you already run a fleet of standard rugged devices, add one line requiring that the hazardous area handsets be manageable from the same console with the same policy set. Two consoles is a recurring cost your IT team will pay forever.
7. Voice, radio and push to talk
Field crews communicate by voice first and everything else second. The technical detail here is what decides whether the device replaces a two-way radio or ends up carried alongside one.
- Cellular bands required for every country of use, with VoLTE support stated.
- Wi-Fi standards and enterprise authentication, plus Wi-Fi calling if it is part of the coverage plan for indoor or offshore areas.
- Push to talk over cellular, naming the platform you use, plus interworking with the existing radio system through a gateway if one is in place.
- Speaker output level, measured, against the noise levels in the areas of use. A handset that cannot be heard next to a compressor will not be used.
- Accessories: headsets, remote speaker microphones, holsters and vehicle mounts. Every accessory that connects to the device electrically must itself be covered by the certification. An uncertified headset plugged into a certified handset is a non-compliant assembly, and this is one of the most common findings in an Ex equipment audit.
8. Lone worker and location
Lone worker functions sell devices and disappoint buyers, usually because nobody separated the feature from the system around it.
- Which alarms are required: manual panic, man-down by tilt, no-motion, and any pre-alarm and cancellation behaviour.
- Whether the alarm function is an application feature or a certified safety function, and if a functional safety claim is made, the standard and level it is assessed against. Ask this explicitly; the honest answer for most handsets is that it is a software feature.
- Where the alarm goes, who is monitoring it around the clock, and what the escalation is if the alarm is not acknowledged.
- Location: four-constellation GNSS improves fix time and accuracy outdoors and around structures, but no satellite system works reliably inside a process module or a tank. If indoor location is a requirement, specify the infrastructure that will deliver it rather than expecting the handset to solve it.
- Battery consequences of continuous location reporting, stated in the endurance assumption in section 4.
9. Repair, spares and the service route
An intrinsically safe device cannot be opened by a general phone workshop. Repair of Ex equipment is governed by IEC 60079-19, and repair facilities can themselves be certified under the IECEx service facility scheme. A repair performed outside that framework does not just void a warranty, it removes the basis on which the device is permitted in a classified area.
- Named repair route and turnaround target, with the location of the workshop stated.
- Whether the repairer is assessed against IEC 60079-19, and whether a certified service facility is used.
- Warranty term, and what specifically voids it.
- Spare pool sizing and where the pool is held, with in-country holding stated where import clearance is slow.
- Availability commitment for spares and batteries after end of production.
- What happens to a device that fails its next periodic inspection under IEC 60079-17.
10. The documentation pack
Require the documents as a deliverable of the award, indexed, in one submission. The full list and how to check each item is the subject of a separate guide in our insights library, but at minimum:
- Certificate of conformity and its full schedule.
- All specific conditions of use, where the certificate number carries an X suffix.
- EU and, where applicable, UK declarations of conformity.
- Ingress and mechanical test reports.
- Radio approvals for each country of use.
- Battery documentation, including the UN 38.3 test summary.
- Instruction manual in the languages required at site.
- A photograph of the actual product label, to be compared character by character with the certificate marking.
The five mistakes that cost the most
- Specifying by marketing category. “Explosion proof phone” or “ATEX phone” as the whole requirement lets a Zone 2 device bid against a Zone 1 need. Name the zone, the EPL and the concept.
- Forgetting dust. A gas-only certificate is silent on Zone 21, not partially compliant with it.
- Ignoring the ambient range. The certified range is a hard limit and it is frequently narrower than the commercial operating range on the datasheet.
- Leaving accessories out of scope. Headsets, cables and docks form part of the certified assembly. Buying them separately from a general supplier breaks it.
- Treating the repair route as an afterthought. The first failed handset is when the route gets tested, and by then the fleet is deployed.
A note on evaluating a pre-launch device
If a supplier is offering a device whose certification is still in progress, that is not automatically disqualifying, but it changes what you can ask for. Request the certification programme in writing: which schemes, which certification body, which standards and editions, and the target dates. Ask what is not held today, in plain words. Run handling and device management trials in a non-hazardous area, and hold the classified-area pilot until the certificate exists.
The SAMS IS-04Z1 sits in exactly that position. It is designed for Zone 1 and Zone 21 with a Qualcomm Snapdragon octa-core platform, a 4,000 mAh battery, IP68 and rugged build, a 50 MP PDAF camera, Android 16 with EMM and MDM support, 4G LTE, Wi-Fi, Bluetooth, NFC and four-constellation GNSS, with an ATEX target marking of II 2 G Ex ib IIC T4 and a NEC 500 Class I Division 1 target. Certification is in progress and launch is Q4 2026, so the datasheet and the certification schedule are what a buyer should be asking us for today. Country requirements are set out on the market pages, including the UAE, the United Kingdom, Nigeria and India.
Frequently asked questions
Can you change the battery of an intrinsically safe phone in a hazardous area?
Only if the certificate permits it, so confirm this in writing. Certificates almost always require charging outside the hazardous area, and often require battery changes outside it too. Only cell types listed in the certificate schedule may be fitted, and substituting a visually identical cell invalidates the certification. These conditions must reach users through site procedures and toolbox talks.
Is a man-down alarm on a rugged phone a safety function?
Usually not. For most handsets the honest answer is that lone worker alarms are a software feature. Ask explicitly whether the alarm is an application feature or an assessed safety function, and if a functional safety claim is made, which standard and level apply. Also specify where alarms go, who monitors them around the clock and the escalation route.
How should a buyer handle the camera on a hazardous area smartphone?
Decide the policy before the tender. Common options are a camera disabled centrally by device management and enabled under a photography permit, geofenced or application-level restriction, restriction to a designated inspection or permit application, or a camera-free variant. Write the mechanism into the specification, because security reviewers need to know whether the user can reverse it.
Can a buyer evaluate a smartphone whose Ex certification is still in progress?
Yes, with limits. Request the certification programme in writing, covering schemes, certification body, standards, editions and target dates, and ask plainly what is not held today. Run handling and device management trials in a non-hazardous area, and hold any classified-area pilot until the certificate exists. The SAMS IS-04Z1 is in this position, with certification in progress ahead of a Q4 2026 launch.