Brochure

4
IEC STANDARDS and EN
STANDARDS
are identical.
IEC STANDARDS
have
become the universal
reference across Europe
and are adopted along
with other admissible
standards in much of the
rest of the world. IEC uses
three Zones to classify
hazardous environment
conditions based on the
duration and amount of
combustible exposed. IEC is
continuously reviewed by a
technical board for updates
and revisions.
IEC/ATEX
INTERNATIONAL ELECTROTECHNICAL COMMISSION (IEC)
Founded in 1904, the IEC is now considered the world’s largest electrotechnology organization with over 130
countries as members and over 10,000 experts contributing to its standards.  e IEC code de nes hazardous
locations as Zones. Zones de ne the amount of time rated equipment is exposed to hazardous atmospheres.
Zone 0 locations feature continuous or extended exposure to  ammable gases or vapors. Zone 1 locations have an
intermittent presence of  ammable gases or vapors, typically as a result of leakage. Zone 2 are locations in which
 ammable gases or vapors are not likely to occur in normal operation, but may become present upon the failure
of equipment or through an accident.  e exposure is unlikely and, if it does occur, it will do so infrequently and
for only a short period of time. Atmospheres of combustible dusts are rated as Zone 20, 21 or 22. Zones 20, 21
and 22 correspond with Zones 0, 1 and 2 in identifying the amount of exposure to the hazardous atmosphere.
IEC Groupings rate locations on whether the hazard is a mine (Group I) or an ignitable atmosphere above ground
(Group II). IEC Subdivisions label the ignitability of the atmosphere with “A” being the least ignitable and “C”
being the most.
ATEX DIRECTIVE
 e ATEX Directive is the  rst uniformed code which deals with the Essential Health and Safety Requirements
(EHSR’s) enacted by the European Union for equipment that is either used within, or connected to equipment
located within, potentially hazardous environments. It includes safety devices, controllers, regulatory devices and
other equipment whose failure would provoke an explosion.
Area Classification - IEC vs NEC/CEC (Class/Division/Group)
IEC vs NEC “T” Ratings Temperature Classification Comparison 
In ammable Material IEC/CENELEC NEC/CEC
Temperatures in ºC IEC NEC/CEC
Gases And Vapors Zone Equipment Group Gas Group Class Division Group
Acetylene 0, 1 or 2 II C I 1 or 2 A 85 T6 T6
Hydrogen 0, 1 or 2 II B + H
2
I 1 or 2 B 100 T5 T5
Propylene Oxide
0, 1 or 2 II B I 1 or 2 B
120 T4 T4A
Ethyl Oxide 135 T4 T4
Butadiene 160 T3 T3C
Cyclopropane
0, 1 or 2 II B I 1 or 2 C
165 T3 T3B
Ethyl Ether 180 T3 T3A
Ethylene 200 T3 T3
Acetone
0, 1 or 2 II A I 1 or 2 D
215 T2 T2D
Benzene 230 T2 T2C
Butane 260 T2 T2B
Propane 280 T2 T2A
Hexane 300 T2 T2
Paint Solvents 450 T1 T1
Natural Gas
 “T” rating classifications list the ignition point of the hazardous atmosphere. For safe usage, fixture “T” ratings must be below that of the surrounding atmosphere.