Prior to UK entry into the European Union, electrical equipment for hazardous area was manufactured to British Standard BS 4683. Equipment built and certified to this standard would display the mark ‘EX’ on the label, which indicated that the equipment was explosion protected (do not confuse with explosion-proof, which is entirely different).
In addition, the label was also marked with a ‘crown’ symbol, which was the distinctive mark for the UK test house BASEEFA.
Because of the differences in standards, UK equipment could not be used in the other European countries, and vice-versa.
European co-operation resulted in the development of harmonised standards, know as “Euronorms”, for which the first English version was published as BS5501. The second generation of the UK version, which replaced this, carried the Euronorm numbering in the EN 500—series. Equipment marking for EN500—was ‘EEx’.
International Standards are now identical to the Euronorms, and carry numbers in the IEC60079 series. The identical European standards carry the EN60079-1. The marking for equipment manufactured to IEC/EN60079 standards is ‘Ex’.
The latest (at March 2015) standards are:
| IEC | Gas/ Dust | Euronorms | |||
| IEC Number | Dated | Constructional standards (Type of Protection) | Latest EN (H = Harmonized EN) | Old EN number | |
| IEC 60079-0 Ed 6 | 2011-06 | General Requirement | G & D | EN 60079-0:2012 H | 50 014 |
| IEC 60079-1 Ed 7 | 2014-06 | Flameproof Enclosure | G | EN 60079-1:2007 H | 50 018 |
| IEC 60079-2 Ed 6 | 2014-07 | Pressurised Equipment ‘p’ | G | EN 60079-2:2007 H | 50 016 |
| IEC 60079-5 Ed 4 | 2015-02 | Power Filling ‘q’ | G | EN 60079-5:2007 H | 50 017 |
| IEC 60079-6 Ed 4 | 2015-02 | Oil Immersion ‘o’ | G | EN 60079-6:2007 H | 50 015 |
| IEC 60079-7 Ed 5 | 2015-06 | Increased Safety ‘e’ | G | EN 60079-7:2007 H | 50 019 |
| IEC 60079-11 Ed 6 | 2011-06 | Intrinsic Safety ‘I’ | G & D | EN 60079-11:2012 H | 50 020 |
| IEC 60079-13 Ed 1 | 2010-10 | Pressurised room ‘p’ | G | ||
| IEC 60079-15 Ed 4 | 2010-01 | Type of Protection ‘n’ | G | EN 60079-15:2010 H | 50 021 |
| IEC 60079-16 Ed 1 | 1990-05 | Artificial ventilation for analyser houses | G | ||
| IEC 60079-18 Ed 4 | 2014-12 | Encapsulation ‘m’ | G & D | EN 60079-18:2009 H | 50 028 |
| IEC 60079-25 Ed 2 | 2010-02 | Intrinsic safety electrical systems ‘I’ | G & D | EN 60079-25:2010 H | 50 039 |
| IEC 60079-26 Ed 3 | 2014-06 | Equipment with Equipment Protection Level ‘Ga” | G | EN 60079-26:2007 H | |
| IEC 60079-27 Ed 2 | 2008-01 | Fieldbus intrinsically safe concept (FISCO) is now included in 60079-11 | G | EN 60079-27:2008 H | |
| IEC 60079-28 Ed 2 | 2015-02 | Protection of optical radiation system | G | EN 60079-28:2007 H | |
| IEC 60079-29-1,2,3,4 | 2007-15 | Gas detector | EN 60079-29:2007 H EN 60079-29: 2010 H | ||
| IEC 60079-30 1&2, Ed 1 | 2007-01 | Electrical trace heating | EN 60079-30-1:2007 H | ||
| IEC 60079-31 Ed 2 | 2013-11 | Equipment dust ignition protection by enclosure ‘tD’ | D | EN 60079-31:2014 H | |
| IEC 60079-32 1&2, Ed 1 | 2013-08 2015-02 | Electrostatic hazard | |||
| IEC 60079-33 Ed 1 | 2012-09 | Special protection ‘s’ | |||
| IEC 60079-35 1&2, Ed 1 | 2011-05 2011-12 | Caplights for use in mines | EN 60079-35-1:2011 | ||
| “Codes of Practice” | |||||
| 60079-10-1 Ed 1 | 2008-12 | Classification of hazardous areas – gases | G | ||
| 60079-10-2 Ed 2 | 2015-01 | Classification of hazardous areas – dusts | D | ||
| 60079-14 Ed 5 | 2013-11 | Electrical installation in hazardous areas | G & D | ||
| 60079-17 Ed 5 | 2013-11 | Inspection and maintenance of equipment in hazardous areas | G & D | ||
| 60079-19 Ed 3+Am1 | 2015-03 | Repair and overhaul | G & D | ||
| 60079-20-1 Ed 1 | 2010-01 | Data for flammable gases | G | EN 60079-20-1:2010 H |
The EU ATEX Directives are now in force in Europe and the certification authorities are known as Notified Bodies (NB). Each has their own unique NB number, which will be marked on the certification labels of ATEX approved equipment and systems.
Notified Bodies in the UK include Baseefa Ltd (NB Number 1180), SIRA Certification Service (NB 0518), and ITS Testing and Certification (NB 0359).
Some of the European Notified Bodies are shown on the map:
