# Class II — Certification marks and hazardous-area classifications: cross-market equivalences

For Class II, stated equivalent is Zone 20/21/22; meaning is NEC separates dust into Class II (Groups E, F, G); IEC integrates dust into the same zone framework (Zone 20/21/22) with dust groups IIIA, IIIB, IIIC, verified against its source on 2026-08-11.

- **Designation:** Class II _(verified: appears in the quote below)_
- **Stated equivalent:** Zone 20/21/22 _(verified: appears in the quote below)_
- **Meaning:** NEC separates dust into Class II (Groups E, F, G); IEC integrates dust into the same zone framework (Zone 20/21/22) with dust groups IIIA, IIIB, IIIC _(verified: appears in the quote below)_

## What the source says

> Dust handling: NEC separates dust into Class II (Groups E, F, G); IEC integrates dust into the same zone framework (Zone 20/21/22) with dust groups IIIA, IIIB, IIIC.

## Source

- https://exknowledge.com/pages/nec-500-vs-atex-iec.html

Last verified: 2026-08-11. Review by: 2027-08-11.
Part of [Certification marks and hazardous-area classifications: cross-market equivalences](https://referencesource.org/certification-standards-equivalence/).