Protection concepts North America and Canada

The tables below list the types of protection methods and basic concepts of protection according to US and Canadian standards for electrical equipment that is to be operated or installed in hazardous areas. The matrix is constructed to enable the fast cross referencing of protection concepts for classes and divisions, or classes and zones including the applicable US and Canadian standards. 

For definitions of hazardous zones, please see Hazardous areas according to ATEX, IECEx zones and North American Classes and Divisions section.

Electrical equipment for flammable gases, vapours and mist
US code CAN code Type of protection Basic concept of protection Class I Div Class I Zone
US Standard CA Standard
1 2 0 1 2
AEx e Ex e Increased safety No arcs, sparks or hot surfaces 




ISA 60079-7 CSA E60079-7
(NI) (NI) Non-incendive 




ISA 12.12.01 / FM 3611 C22.2 No. 213
AEx nA Ex nA Non-sparking




ISA 60079-15 CSA E60079-15
(XP) (XP) Explosion proof Contain the explosion and
extinguish the flame





UL 1203 / FM 3615 C22.2 No. 30
AEx d Ex d Flame proof




ISA 60079-1 / UL 1203 / FM 3615 CSA 60079-1
AEx q Ex q Powder filled




ISA 60079-5 CSA E60079-5
AEx nC Ex nC Enclosed break




ISA 60079-15 CSA E60079-15
(IS) (IS) Intrinsic safety Limit energy of sparks and surface temperature




UL 913 / FM 3610 22.3 No. 157
AEx ia EX ia




ISA 60079-11 / FM 3616 CSA E60079-11
AEx ib EX ib




ISA 60079-15 CSA E60079-15
AEx nL EX nL Limited energy




ISA 60079-15 CSA E60079-11
Type X Type X Pressurised Keep flammable gas out




NFPA 496 (FM 3620) NFPA 496
Type Y Type Y




Type Z Type Z




AEx px Ex px




ISA 60079-2CSA E60079-2
AEx py Ex py




AEx pz Ex pz




AEx nR Ex nR Restricted breathing




ISA 60079-15CSA E60079-15
AEx m Ex m Encapsulated




ISA 60079-18CSA E60079-18
AEx ma N/A




N/A
AEx mb




AEx oEx oOil immersion




ISA 60079-6CSA E60079-6



Electrical equipment for combustible dust
US code CAN code Type of protection Basic concept of
protection
Class II Div Class III
Div 1&2
Class II Zone US Standard CA Standard
1 2 0 20 21 22
(DIP) (DIP) Dust ignition protection Keep combustible dust out





UL 1203 / FM 3616 CSA C22.2 No. 25
(NI) (NI) Dust protected





ISA 12.12.01 / FM 3611 CSA C22.2 No. 25
AEx ta Ex ta Protection by enclosure




ISA 60079-31 CSA C22.2 No. 60079-31
AEx tb Ex tb




AEx tc Ex tc




N/A N/A Fibre & flying protection





UL 1203 / ISA 12.12.01 CSA C22.2 No. 25
AEx maD N/A Encapsulation




ISA 60079-18 N/A
AEx mbD




(PX) (PX) Pressurisation





NFPA 496 (FM 3620) NFPA 496
(PY) (PY)





(PZ) (PZ)





AEx pD N/A





ISA 61241-2 N/A
(IS) (IS) Intrinsic safety Limit energy of sparks
and surface temperature






UL 913 / FM 3610 CSA C22.2 No. 157
AEx iaD N/A




ISA 60079-11 N/A
AEx ibD