Page 29 - Electrical Installation in Hazardous Area

8 Electrical installations in hazardous areas

industry in general and organizations such as The Institute of Petroleum
which produced a model code of safe practice6 for the oil industry.
Industry, unlike the govenunental organizations, concentrated much of its
work on the matters associated with how hazardous areas were formed
and matters associated with installation and maintenance. Individual
companies also made significant contributions and, as an example of this,
the RoSPA/ICI Code of Practice7 covering use of electrical equipment in
explosive atmospheres in the chemical industry is probably one of the finest
documents of its type ever produced.

1.5 European legislation

With the accession of the UK to the EU it became subject to EU legislation
in this field. The first such legislation produced was the Explosive Atmo-
spheres Directive 1975'. This Directive was limited to equipment for gas,
vapour and mist risks and was what is described as an optional Direc-
tive, solely concerned with barriers to trade. It did not dictate what must
be used in explosive atmospheres but merely identified equipment which
could not be defined by individual member states as unsuitable for use
in their country. The Directive referred to all constituent parts of electrical
installations capable of use in potentially explosive atmospheres, other than
mines and its Article 4 set the scene as follows:

Member States may not, on grounds of safety requirements for the
design and manufacture of electrical equipment for use in Potentially
Explosive Atmosphere, prohibit the sale or free movement or the use,
for its proper purpose of the electrical equipment (covered by the
Directive)

While this clearly prevented individual member countries from insisting
that all equipment used must comply with individual national require-
ments, it did not prevent equipment complying with national requirements
from use in addition to that complying with the Directive even though these
could differ.
The 1975 Directive also had to define what was required of equipment
to comply with it, and this led to considerable emphasis on the work of
the European Committee for Electrical Standardization (CENELEC)9 which
produced a range of very detailed Standards describing the construction
of suitable electrical equipment (the EN 50 - - - range of European Stan-
dards). These Standards were then given legal status by being referred to in
Supplementary Directives'O or the EU JournaP2. To ensure that equipment
did indeed comply the basic Directive recognized the Distinctive Commu-
nity Mark (Fig. 1.3) which could only be affixed to equipment in compliance
with the Standards referred to in the Supplementary arrangements and
required that this compliance be attested by a Certificate of Conformity
or Inspection Certificate issued by an approved body. The Certificate of
Conformity was for equipment which complied with one of the recognized