Explosive Environments & ATEX Zone 1—Key ConceptsWhat qualifies as a “hazardous location”?Any area where flammable gases, vapours, liquids, dusts, or fibres could mix with air and find an ignition source is deemed hazardous. Typical culprits include gasoline, paint thinners, naturally occurring hydrocarbons, decomposing organic matter, and similar substances. When oxygen, fuel, and an ignition source coexist, fire or explosion is possible.
Our explosion-proof pipe inspection robots are certified for ATEX Zone 1 service (IECEx analogue of Class I, Division 1 in North America, as defined by NFPA 70 / NEC). No pipe-inspection robot on today’s market is rated for ATEX Zone 0 or carries full intrinsic-safety approval, so users must confirm the classification of every work site before deployment.
What does “explosion-proof” actually mean?Under NFPA 70 (NEC) the term describes an enclosure built to contain an internal ignition and prevent flames, sparks or hot gases from reaching the surrounding atmosphere. It is not designed to survive an external blast; instead, it stops a small internal event from becoming a large external disaster.
Explosion-proof apparatus must also respect the installation's temperature code - its surface temperature in normal service may never exceed the ignition point of ambient gases or dusts.
North American classification system (Class / Division)Class I – Flammable gases or vapours may exist.
Class II – Combustible or conductive dust is present.
Class III – Easily ignitable fibres or flyings are present.
CI D1 Hazard is present under normal conditions.
CI D2 Hazard appears only under abnormal or infrequent conditions.
Equipment approved for CI D1 is automatically acceptable in CI D2 areas of the same class, gas group and temperature rating.
International (Zone) classification now adopted by the US & CanadaZone 0 – Explosive atmosphere continuously or for > 1,000 h/yr.
Zone 1 – Explosive atmosphere likely in normal operation (≈ 10–1,000 h/yr).
Zone 2 – Explosive atmosphere unlikely or only for < 10 h/yr.
ATEX Zone 1, therefore, matches Class I, Division 1 for gas hazards.
Explosion-proof equipment, being the highest gas-hazard category, can always be installed where Division 2 or Zone 2 standards apply, provided the gas group and temperature class match.
Sources for further referenceNational Fire Protection Association NFPA / NEC (NFPA 70, ANSI/NFPA 70)
ATEX Directives ATEX Directives 2014/34/EU & 1999/92/EC
Underwriters Laboratories (UL) UL / CSA
Know your site’s classification first; then select equipment, such as the Proteus™ ExZ1 pipe inspection crawler, whose protection concept, gas group, and temperature code fully align with that classification.