CENELEC AND IEC NORMATIVES
DIRECTIVE 94/9 EC

I. Why a new Directive?
The main objective of this directive is to stipulate requirements that are essential for the free circulation of products within the European Economic Union.
In order to do this, National Standards need to be harmonized based on article 100A in the Union Treaty.
Starting from July 1, 2003, products must satisfy the requirements of this directive before they can be marketed and transported freely, or used.

Why is directive 94/9 EC called the “New Approach Directive”?
This is the first time that a directive about equipment usable in explosive atmospheres deals with non-electrical equipment and equipment designed to operate in an explosive atmosphere resulting from the presence of combustible dust.
Therefore, zones 20, 21 and 22 are complementary to zones 0, 1 and 2 defined for gases and vapors.
The magnitude of the risks of faults are the same in these zones.
Through its products marking requirements, the directive introduces the concept of zones and gaseous atmospheres and/or atmospheres containing dust in which the equipment may be installed.

II. The general outline
The major elements of this new directive may be identified:
• Application to electrical and non-electrical equipment
• Definition of essential health and safety requirements
• Consideration of all potential dangers originating from equipment, particularly in design and production.
• A single directive for mines (underground) and on the surface.
• Importance of the concept of use conform to equipment
• Definition of procedures for evaluating the conformity of essential requirements based on modules
necessary for addition of conformity marking in a complete specific ‘code’.

How to read the directive markings
Example marking :
0081 II 2 G = marking which certifies conformity
0081 = Notified organization identification – N°. (0081 = LCIE)
= Distinctive community marking for equipment useable in explosive atmospheres
II = Equipment group (surface)
2 = Equipment category
G (or D) = Gas and vapor (D = Dust)

III. The field of application
The directive is applicable to industrial applications and concerns the following equipment :
• Equipment (machines, other equipment, etc…)
• Protection systems (discharge devices, explosion prevention devices, etc…)
• Components (parts with dependent function, terminals, etc…)
• Safety, inspection and adjustment devices designed to be used outside explosive atmospheres, but
which are necessary to provide safety against explosions (relays, barriers, pressure switches
thermostats, etc…)

IV. Exclusions from the field of application
The following equipment is excluded from this directive : • Medical apparatus for use in the medical environment
• Equipment and protection systems related only to the danger of explosion of unstable chemicals
(explosives, pyrotechnic mixes, pyrophoric substances, etc…)
• Equipment in the domestic and non-commercial environment
• Individual protection equipment covered by directive 89/686 CEE
• Ships and off-shore mobile units
• Transport means except of vehicles designed for use in an explosive environment

V. The rules
Member states consider that equipment (Apparatus and protection systems) accompanied by the declaration of conformity prepared by the manufacturer.
Components are not marked with the “CE” marking, require a written declaration of conformity.

VI. Category of protection
Equipment (“apparatus” according to the directive) is broken down into two groups, Group 1 and Group 2.
• Group I : equipment in this category is designed for underground mine work
• Category M1
• category M2
• Group II : equipment in this category is designed for surface work
• Category 1
• Category 2
• Category 3Within these groups, equipment is classified into categories to define the zone or zones in
which it can be used.

VII. Relations between zones and equipment categories for group II (Tabelle-2)

VIII. Equipment for zones with risks of explosion in the presence of combustible (or inflammable) dust

Zone 20:
This is a location in which an explosive atmosphere exists in the form of a cloud of combustible dust mixed with air at all times either present or during long periods or frequently.
Zone 21:
This is a location in which an explosive atmosphere in the form of a cloud of combustible dust mixed with air is likely to occur occasionally during normal operation.
Zone 22:
This is a location in which an explosive atmosphere in the form of a cloud of combustible dust mixed with air is not likely to occur during normal operation. How ever way occur for a short period.

Choice of the product temperature class…
If the dust is in a cloud : T° max. of product <= 2/3 T.cl
If the dust is in a layer (Max. 5mm thickness) : T° max. of product <= T.5mm – 75K

Example: Dust of sugar (non conducting)
• Self-inflammation temperature in layer = 400 °C
• Self-inflammation temperature in cloud = 370°C
Equipment selection: IP = IP 6 X (for zone 21)

Temperature class:
• Dust in layer: 400 – 75 = 325 °C Maximum product temperature < 325 °C
• Dust in cloud : 2/3 de 370° = 246 °C
Maximum product temperature < = 246 °C

If the dust is present in a cloud and in a layer frequently assume the worst case, therefore EC 0081 II 2D (246°C maximum).