Introduction
Operating / Mounting instruction
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192-550003N10 ETH ATEX December 2019
1.5
Introduction to ATEX
In this chapter you can read about:
Explosive atmospheres ...................................................................................................... 8
Harmonized European ATEX Standard.............................................................................. 8
Zone classification / device categories ............................................................................... 8
Type of explosion protection .............................................................................................. 9
Explosion subgroup ......................................................................................................... 10
Temperature classes ....................................................................................................... 10
ATEX and machinery directive ......................................................................................... 10
ATEX = “ATmosphère EXplosible”
Introduction to the European ATEX directive
1.5.1.
Explosive atmospheres
Directive 2014/34/EC defines an explosive atmosphere as a mixture of:
a) flammable substances - gases, vapors, mists or dusts
b) and air
c) under defined atmospheric conditions
d) in which, after ignition has occurred, combustion spreads to the entire unburned
mixture
(NOTE: dust may not burn entirely after ignition).
A “potentially explosive atmosphere” is an atmosphere which could become
explosive due to local and operational conditions. Devices concerned by directive
2014/34/EC are defined as designed for the use in potentially explosive
atmospheres.
1.5.2.
Harmonized European ATEX Standard
The EC accepted two harmonized directives for health and safety.
Requirements for machinery and equipment
Directive 2014/34/EC (ATEX 95a) defines the minimum safety requirements in EU
member states for products used in potentially explosive atmospheres.
Requirements for OEM / user
ATEX directive 99/92/EC (ATEX 137) sets out the minimum requirements for
improving the health and safety protection of workers potentially at risk from
explosive atmospheres with regard to workplace, working conditions and the
handling of products and materials. This directive classifies the workplace into
zones and defines criteria for categorizing the products within the zones.
