HAZLOC Standards
Hazardous locations standards in the USA are developed by one of a number of standards development organisations accredited by ANSI, such as UL, FM, and NFPA.
A selection of US standards are presented below, alongside the IEC standard covering the same material.
USA standards
| Type of protection | Symbol | IEC Standard | USA |
|---|---|---|---|
| General requirements | IEC 60079-0 | UL 60079-0 ISA 60079-0 FM 3600 |
|
| Flameproof enclosures | d | IEC 60079-1 | UL 60079-1 ISA 60079-1 FM 3615 UL 1203 |
| Pressurized enclosures | p | IEC 60079-2 | FM 3620 ISA 60079-2 |
| Powder filling | q | IEC 60079-5 | UL 60079-5 ISA 60079-5 |
| Oil immersion | o | IEC 60079-6 | UL 60079-6 ISA 60079-6 |
| Increased safety | e | IEC 60079-7 | UL 60079-7 ISA 60079-7 |
| Intrinsic safety | i | IEC 60079-11 | FM 3610 ISA 60079-11 UL 913 UL 60079-11 |
| Type of protection 'n' | n | IEC 60079-15 | FM 3611 ISA 60079-15 ISA 12.12.01 UL 60079-15 UL 1604 |
| Encapsulation | m | IEC 60079-18 | UL 60079-18 ISA 60079-18 |
| Intrinsic safety | i | IEC 60079-11 | FM 3610 ISA 60079-11 ISA 61241-11 |
| Encapsulation | m | IEC 60079-18 | ISA 60079-18 ISA 61241-18 |
| Protection by enclosure | t tD DIP |
IEC 60079-31 | FM 3616 ISA 60079-31 ISA 61241-1 UL 1203 |
| Pressurization | pD | IEC 61241-4 | FM 3620 ISA 61241-2 |