Reference Source

Group C

For Group C, category is gas group; iec / atex designation is IIB; basis or note is MESG 0.50–0.90 mm, recorded from its source on 2026-08-06.

Category
gas group our reading
North American designation
Group C
IEC / ATEX designation
IIB verified
Basis or note
MESG 0.50–0.90 mm
Sourceexknowledge.com
Verified2026-08-06
Review by2028-08-05
DatasetNorth American vs IEC/ATEX explosion protection designations

Values marked our reading are our classification of what the source says — the source does not print them in those words. The quote below is the evidence for each one; judge it yourself.

What the source says

C | IIB | Ethylene, ethyl ether | 0.50–0.90 mm

exknowledge.com, retrieved 2026-08-06

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 — deciding between them is yours, not ours.

Basis or note

exknowledge.com says basis or note is MESG 0.50–0.90 mm, as of 2026-08-06.

C | IIB | Ethylene, ethyl ether | 0.50–0.90 mm

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

ldpi-inc.com says basis or note is Ethylene, as of 2026-08-06.

Ethylene | C | 450 | 842 | 1,200 PSI | IIB

https://ldpi-inc.com/resources/classification-codes/class-1-locations/

Sources

Last verified against source: 2026-08-06. Due for re-check by 2028-08-05. This page as Markdown · OKF bundle · full dataset as JSON.