# T4 — Certification marks and hazardous-area classifications: cross-market equivalences

For T4, applies to is 135º C (275ºF), verified against its source on 2026-08-11.

- **Designation:** T4 _(verified: appears in the quote below)_
- **Applies to:** 135º C (275ºF) _(verified: appears in the quote below)_

## What the source says

> 135º C (275ºF) T4

## Source

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

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/).