Compliance & Classification
Hazardous location classification
Class I and Class II, Divisions 1 and 2, dust Groups E, F and G, temperature codes, intrinsic safety and ATEX — the hazardous-location framework explained.
Start with the classification, not the product
Almost every difficult equipment conversation starts in the wrong place — with a machine, rather than with the classification of the space it has to work in. The Class tells you what kind of hazard is present, the Division tells you how often it is expected, the Group tells you which material, and the temperature code caps how hot the equipment may get. Equipment follows all four together.
Classification is assigned by your own electrical or process engineer and accepted by the authority having jurisdiction. These pages explain the framework so the conversation with your supplier can be specific.
Class II — combustible dust
- Classification referenceClass II, Division 1Class II is the combustible-dust classification, and Division 1 is where the dust is airborne in ignitible quantities under normal operation — or where equipment failure could both produce that cloud and supply the ignition source.Read
- Classification referenceClass II, Division 2Class II, Division 2 applies where combustible dust is present but is not normally suspended in ignitible concentrations — dust accumulations exist, and abnormal operation could put enough of it into the air to matter..Read
- ComparisonClass II Div 1 vs Div 2For combustible dust the division turns on whether an ignitible cloud is part of normal operation or only appears when something malfunctions.Read
- Classification referenceClass II Groups E, F & GClass II locations are subdivided by the dust itself, because conductivity and combustion behaviour differ enormously between aluminium powder, coal dust and flour.Read
- StandardsCombustible dust classificationOne of the most common questions about dust safety has a surprising answer: there is no single comprehensive OSHA combustible dust standard.Read
Class I — gases and vapours
- Classification referenceClass I, Division 1Class I covers flammable gases, flammable liquid-produced vapours and combustible liquid-produced vapours.Read
- Classification referenceClass I, Division 2Class I, Division 2 covers locations where flammable gas or vapour is handled, processed or stored, but is confined in closed containers or systems during normal operation — so an ignitible atmosphere appears only if that containment fails..Read
- ComparisonClass I Div 1 vs Div 2Both divisions describe areas where flammable gas or vapour is a factor.Read
Equipment standards & certification
- StandardsUL 1203UL 1203 is the North American standard for explosion-proof and dust-ignition-proof electrical equipment intended for hazardous (classified) locations.Read
- Protection conceptsIntrinsic safetyIntrinsic safety is a specific, defined protection concept — not a general synonym for safe in a hazardous area.Read
- StandardsNFPA 70 / NECThe National Electrical Code, published as NFPA 70, is where the North American hazardous location framework comes from.Read
Combustible dust standards
- StandardsNFPA 660For years the combustible dust requirements lived across half a dozen NFPA documents — a fundamentals standard, several industry-specific ones, and a separate standard for metals.Read
- StandardsNFPA 652NFPA 652 was the fundamentals standard — the document that established a common baseline across every industry handling combustible dust, sitting above the industry-specific standards rather than replacing them.Read
- StandardsNFPA 654NFPA 654 was the general-industry standard for combustible particulate solids — the document that applied where a facility manufactured, processed, blended, conveyed or handled combustible dusts that did not fall under one of the more specific standards.Read
- StandardsNFPA 484Combustible metals were governed by their own standard for a straightforward reason: they behave differently from organic dusts in ways that change both prevention and response.Read
- RegulationOSHA & combustible dustFacilities frequently ask which OSHA combustible dust standard applies to them, and the answer surprises people: there isn't one comprehensive standard.Read
International schemes
- StandardsATEXATEX is the European framework covering explosive atmospheres.Read
- StandardsIECExIECEx is the international certification scheme for equipment used in explosive atmospheres.Read
- JurisdictionsATEX vs North AmericanEurope and North America classify hazardous areas differently, and equipment approved under one scheme is not automatically acceptable under the other.Read
These pages are explanatory. They do not classify your facility, they do not replace the applicable code or your Dust Hazard Analysis, and they are not a substitute for advice Our listing is CSA Certificate 70122393, assessed against UL 1203 (5th Edition). It carries two scopes: the EX1 HEPA line for Class I, Gp. D and Class II, Gps. E, F and G at T3C; the EV EX HEPA line for Class II, Div. 2, Gps. F and G only. Ask us for the documents that apply
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