# (IS) — Certification marks and hazardous-area classifications: cross-market equivalences

For (IS), market / system is US; stated equivalent is Division 1; applies to is Class I; governing standard / law is UL 913 / FM 3610, verified against its source on 2026-08-11.

- **Designation:** (IS) _(verified: appears in the quote below)_
- **Market / system:** US _(verified: appears in the quote below)_
- **Stated equivalent:** Division 1 _(verified: appears in the quote below)_
- **Applies to:** Class I _(verified: appears in the quote below)_
- **Governing standard / law:** UL 913 / FM 3610 _(verified: appears in the quote below)_

## What the source says

> (IS) US Class I Division 1 UL 913 / FM 3610

## Sources disagree

More than one authority states this, and they do not state the same
thing. Both are reproduced with the source each came from.

### Applies to

euroswitch.com says applies to is **Class I**, as of 2026-08-11.

> (IS) US Class I Division 1 UL 913 / FM 3610

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

euroswitch.com says applies to is **Class II**, as of 2026-08-11.

> (IS) US Class II Division 1 UL 913 / FM 3610

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

euroswitch.com says applies to is **Class III**, as of 2026-08-11.

> (IS) US Class III Division 1 UL 913 / FM 3610

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


## 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/).