Nonincendive equipment for Class I/II Division 2 and Class III hazardous locations (USA/Canada); successor to ISA 12.12.01.
The standard specifies minimum construction, design and marking requirements for electrical equipment or parts intended for Class I and Class II Division 2 and Class III Division 1 and 2 hazardous locations under the North American classification system (Class I: gases and vapors, Class II: combustible dusts, Class III: fibers and flyings; Division 1: more frequent hazard, Division 2: less frequent hazard).
Nonincendive equipment does not ignite the surrounding atmosphere in normal operation, although it may contain electronic components or field wiring in circuits capable of ignition. The standard harmonizes test methods for determining suitability of equipment, circuits and components with respect to ignition of specified gas/vapor-air mixtures, combustible dust, fibers or flyings.
Market: USA and Canada.
An “ANSI/ISA-12.12.01” or “UL 121201” entry in a datasheet for an electronic breaker, relay or power supply means the manufacturer references Division 2 (and Class III Div 1/2) requirements; evidence is a listing or certificate from an NRTL (UL, CSA, Intertek) with file number and Class, Division and Group marking on the product.
The standard addresses explosion hazards in North America and does not demonstrate ATEX/IECEx or railway-standard compliance. Listings to ISA 12.12.01 were subject to review and transfer to UL 121201 / CSA C22.2 No. 213:2017 by 30 June 2020; listings not updated lost validity after that date.
In September 2017, ISA 12.12.01 transferred to UL as UL 121201, 9th Edition (2017-09-15). An NRTL evaluates the design, performs testing to the standard, issues a listing report with authorization to use the mark, and then conducts production follow-up.
According to the Intertek Standards Update Notice, all existing listing reports required review against the new requirements, new evaluations were conducted to the revised standard, and manufacturers migrated documentation from ISA 12.12.01 to harmonized UL 121201 / CSA C22.2 No. 213:2017 with an effective date of 2020-06-30. UL states that equipment complying with the ISA/UL 60079 or CSA 60079 series is accepted without additional UL 121201 evaluation.
Check the Class/Division/Group designation and temperature code, the NRTL file number (e.g. UL File E…), and whether the listing references UL 121201 or withdrawn ISA 12.12.01; verify the record in UL Product iQ or the CSA / Intertek database.
