# Zone 0 — Certification marks and hazardous-area classifications: cross-market equivalences

For Zone 0, stated equivalent is 1G, verified against its source on 2026-08-11.

- **Designation:** Zone 0 _(verified: appears in the quote below)_
- **Stated equivalent:** 1G _(verified: appears in the quote below)_
- **Meaning:** Explosive atmosphere continuously or for long periods (>1000 hrs/yr) _(per exknowledge.com, not stated by the source above)_

## What the source says

> Zone 0 1G Ga

## What exknowledge.com says

> Zone 0 | Explosive atmosphere continuously or for long periods (>1000 hrs/yr)

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

## Source

- https://www.euroswitch.com/wp-content/uploads/euroswitch-hazardous-area-guide_V6.pdf
- 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/).