Explosion proof cameras are electrical equipment installed where flammable gases, vapors or combustible dust may be present. There, the camera is judged first by whether an independent body has tested the complete assembly and confirmed that it cannot become an ignition source. That is what ATEX, IECEx and FM certification provides. This guide explains how the three systems differ, how to read the marking on the camera label, what a certificate must show, and how to check that the paperwork matches the product you are offered. It is the certification companion to our pillar guide, Understanding Explosion Proof Cameras.
ATEX, IECEx and FM/NEC in plain terms
All three answer the same question: has this equipment been tested and shown to be safe for a defined type of hazardous area? They differ in where they apply, who issues the certificate, and what classification language they use.
ATEX (European Union)
ATEX comes from the French “Atmosphères Explosibles” and is a legal requirement in the EU. The Equipment Directive 2014/34/EU covers manufacturers and sets the essential health and safety requirements for equipment used in potentially explosive atmospheres; the Workplace Directive 1999/92/EC covers the end user and the classification of the workplace into zones. For Zone 1 equipment (Category 2) a Notified Body issues an EU-Type Examination Certificate against the EN IEC 60079 standards, and the manufacturer issues a Declaration of Conformity and applies the CE mark with the Ex hexagon. Great Britain follows the parallel UKCA route.
IECEx (international)
IECEx is the international scheme run under the International Electrotechnical Commission. It uses the same IEC 60079 series that ATEX relies on, which is why the two markings look nearly identical. An accredited certification body (ExCB) tests the product and issues a Certificate of Conformity, listed on the public IECEx online register. IECEx is not a law on its own. It is accepted, or used as the technical basis for national approval, in many countries across the Middle East, Asia, Africa, South America and Australia, and national schemes such as INMETRO in Brazil and PESO in India are built on the same IEC 60079 family.
FM, cFMus and the NEC (United States and Canada)
In North America, hazardous locations are defined by the National Electrical Code (NFPA 70) and the Canadian Electrical Code. The traditional method is the Class/Division system of NEC Articles 500 to 503. The Zone system, which mirrors IEC practice, is available through NEC Articles 505 and 506. Equipment must be listed or approved by a Nationally Recognized Testing Laboratory. FM Approvals is one of these, and the cFMus mark indicates approval for both Canada and the United States. UL and CSA are other common marks. A North American certificate can cover the Division system, the Zone system, or both.
The practical point: an ATEX certificate alone does not make a camera legal in a US refinery, and an FM certificate alone does not satisfy an EU inspector. Our overview of global certifications walks through the regional schemes one by one.
How to read an Ex marking
The label marking condenses the certificate into one line. Take a typical gas-area marking for a Zone 1 camera:
Ex db IIB+H2 T6 Gb
- Ex means the equipment is certified for explosive atmospheres.
- db is the protection concept: “d” is flameproof enclosure (the housing contains an internal explosion and cools escaping gases below ignition temperature), and “b” is the Equipment Protection Level, suitable for Zone 1.
- IIB+H2 is the gas group. IIA covers gases such as propane, IIB covers ethylene and similar gases, and IIC covers hydrogen and acetylene. “IIB+H2” means Group IIB plus hydrogen specifically.
- T6 is the temperature class: the maximum surface temperature does not exceed 85 °C. T6 is the most conservative class; T4 corresponds to 135 °C and T1 to 450 °C.
- Gb is the Equipment Protection Level: “G” for gas, “b” for Zone 1. A dust marking uses “D” and looks like Ex tb IIIC T85°C Db, where “tb” is protection by enclosure, “IIIC” covers conductive dust, and the surface temperature is stated in degrees.
ATEX adds a prefix such as II 2 G (Equipment Group II, surface industry; Category 2, suitable for Zone 1; G for gas) or II 2 D for dust. The North American Zone marking replaces “Ex” with AEx (for example AEx db IIB+H2 T6 Gb) to show evaluation to the US adoption of the IEC standards.
Class, Division and Group
The North American Division marking reads differently but carries the same information:
- Class I is flammable gas or vapor; Class II is combustible dust; Class III is ignitable fibers and flyings.
- Division 1 means the hazard is present under normal operation; Division 2 means only under abnormal conditions. Division 1 roughly corresponds to Zones 0 and 1, Division 2 to Zone 2.
- Groups A, B, C, D are the Class I gas groups (A acetylene, B hydrogen, C ethylene, D propane). Groups E, F, G are the Class II dust groups (metal, carbonaceous and other combustible dust).
So Class I Division 1 Groups B, C, D T6 is the Division-system equivalent of a Zone 1, IIB+H2, T6 rating, and Group B is what matters for hydrogen.
What a certificate must show, and how to verify it
A certificate is only useful if you can match it to the product on the shipping crate. Whichever scheme applies, the document should show:
- Certificate number and issuing body. ATEX certificates carry the Notified Body number; IECEx certificates carry the ExCB code and are searchable on the IECEx register; FM certificates carry an FM project number.
- Manufacturer and exact product designation. The model or series on the certificate must be the one you are buying, including option codes.
- The full marking string, exactly as on the label: protection concept, gas and dust groups, temperature class and EPL.
- Certified ambient temperature range, because the temperature class is only valid inside it. A camera that is T6 up to +50 °C may be T5 or T4 at higher ambients.
- Specific conditions of use. An “X” at the end of a certificate number means special conditions apply, for example fastener grade or cable entry requirements. These belong in the installation drawings.
- Standards tested to (for example IEC 60079-0 and IEC 60079-1), issue date and supplements. Supplements record design changes; a certificate that has not been maintained may not cover the current build.
Verification is simple once you have the number. Look up the IECEx certificate on the public register. Ask for the ATEX EU-Type Examination Certificate and Declaration of Conformity, and check that the Notified Body number on the certificate matches the number next to the CE mark on the label. For FM, request the certificate PDF. Then compare the nameplate on the delivered unit to the certificate; any mismatch in model, marking or temperature range should stop the installation until the vendor explains it.
There is also a factory quality requirement behind the product certificate: ATEX requires a Quality Assurance Notification (QAN) and IECEx a Quality Assessment Report (QAR), both issued after an audit of the manufacturer, confirming that shipped units are built the same way as the tested ones.
Why cameras are certified as an assembly
A flameproof camera is not a certified housing with any camera inside. The certificate covers the complete assembly: enclosure, window, fasteners, cable entries, heater, power supply and the specific camera modules approved for that enclosure. Change the module, add a power component with different heat output, or drill an extra entry, and the tested thermal and pressure behavior no longer applies.
This is why a camera “built into an explosion proof box” by an integrator without a new assembly certificate is not a certified explosion proof camera. When comparing offers, ask whether the certificate names the complete camera assembly or only the empty enclosure. Only the first is acceptable for a Zone 1 or Division 1 installation.
What to ask a vendor
- Which certificate covers the complete camera assembly, including the camera module and power option I am ordering? Please send the PDF.
- Does it cover my site classification: Zone 1 or Division 1, the gas group (IIB+H2 or Group B for hydrogen), and dust if applicable?
- What is the certified ambient range, and which temperature class applies at my site’s maximum ambient?
- What are the specific conditions of use (the “X” conditions), and what cable entries are required?
- Can you provide the full submittal package: certificates, declaration of conformity, manual and drawings?
If a supplier cannot answer the first question with a document, stop there.
How Spectrum documents its certifications
Spectrum publishes its certificates by product family on the certifications page: FM US, FM Canada, ATEX, IECEx, INMETRO and PESO documents, plus the ISO 9001 and ISO 14001 certificates, the IECEx QAR and the ATEX QAN. Complete packages for audits and submittals are available on request.
As a worked example, the F2xx family of F-Series fixed cameras is FM certified under certificates FM24US0209X and FM24ATEX0026X for Class I Division 1 Groups B, C, D; Class II/III Division 1 Groups E, F, G; Zone 1 AEx db IIB+H2 Gb; and Zone 21 AEx tb IIIC Db, with ATEX and IECEx Ex db certification as well. The certified ambient ranges show how the temperature class moves with ambient: -50 to +50 °C at T6, -50 to +65 °C at T5, and -50 to +90 °C at T4, with wireless versions rated from -40 °C. Group B and gas group IIB+H2 cover hydrogen atmospheres. The enclosure has three cable entries (3/4″ 14-NPT or M25x1.5), a heater with thermostat, and accepts 120-240 Vac, 12 Vdc, 24 Vdc or PoE 802.3bt at up to 90 W. The F-Series is rated Type 4X / IP66. The D-Series dome cameras and the rest of the explosion proof camera range carry their own certificate sets on the same page.
For a specific site classification, request a quote with your Zone or Division, gas group and ambient range, and the matching certificate will be included with the proposal. Standard configurations can also be ordered through the official online store.
Frequently asked questions
Is an IECEx certificate accepted in Europe or the United States?
No. IECEx is the technical basis for many national approvals, but the EU requires ATEX certification under Directive 2014/34/EU, and the United States and Canada require approval by a recognized laboratory such as FM, UL or CSA under the NEC or CEC. A product can hold all three.
What does the “X” at the end of a certificate number mean?
It flags specific conditions of use, listed in the certificate text, such as fastener material, cable entries, or the ambient range in which a temperature class applies. The installer must follow them for the certification to remain valid.
Does Ex db IIB+H2 cover hydrogen?
Yes. IIB+H2 means gas group IIB plus hydrogen; the North American equivalent is Group B. Acetylene service needs full Group IIC or Group A coverage, which is a different test.
Can I install a Zone 1 camera in a Division 1 area?
Only if the certificate includes the Division 1 rating. An ATEX Zone 1 certificate does not by itself authorize use in a US Division 1 area. Check for the Class and Division marking the site requires, or an NEC 505 Zone marking where the site is classified under the Zone system.