IEC 60079-11 Revised
IEC 60079-11:1991
Electrical apparatus for explosive gas atmospheres - Part 11: Intrinsic safety 'i'
Gives requirements for the design, construction, testing, and marking of electrical apparatus and electrical systems with type of protection 'i'. Also gives requirements for associated apparatus that is not protected for use within an explosive gas atmosphere but contains both intrinsically-safe circuits and non-intrinsically-safe circuits that can affect the safety of intrinsically-safe circuits.
CHFÂ 320.-
A more recent version of this publication exists:
IEC 60079-11:2023/ISH3:2024