CompEx EX01 - EX04

The CompEx scheme, which includes Gas and Vapours EX01 - EX04, is a globally recognised qualification.

It is supported by the Health and Safety Executive (HSE), the National Inspection Council for Electrical Installation and Contracting (NICEIC) and the Engineering Equipment and Materials Users' Association (EEMUA). 

CompEx is the only Certification Body that offers UKAS accredited cerification for practicioners working in explosive atmospheres.

Find out more about CompEx at AIS Training >>

Course Overview

The CompEx course EX01 - EX04 involves competence based training and assessment for electrical and instrumentation technicians who are working in environments with the potential risk of explosive atmospheres.

Potentially explosive environments include onshore and offshore oil and gas installations and petrochemical plants.

The underpinning knowledge and practical assessment in a CompEx course is provided for electrotechnical personnel who understake the physical installation and assembly of new 'Ex' equipment and perform preventative maintenance and inspections on previously installed equipment.

AIS Training offer the full CompEx Gas and Vapours course including modules:

  • EX01: Preparation and installation of Ex 'd', 'n', 'e' and 'p' electrical equipment in explosive atmospheres
  • EX02: Inspection and maintenance of Ex 'd', 'n', 'e' and 'p' electrical equipment in explosive atmospheres
  • EX03: Preparation and installation of Ex 'i' equipment and systems in explosive atmospheres
  • EX04: Inspection and maintenance of Ex 'i' equipment and systems in explosive atmospheres

CompEx is fast becoming a mandatory requirement on many offshore plants as it offers complete reassurance to employers managing the safety of these potentially hazardous workplaces.

Course Objectives

Delegates completing a CompEx course will be able to;

  • Prepare and install electrical apparatus in potentially explosive atmospheres
  • Inspect and maintain electrical apparatus in potentially explosive atmospheres

Course Content

A CompEx course includes;

  1. DSEAR
  2. Classifications
  3. Gas groups
  4. Dust protection
  5. IP ratings
  6. Impact protection and other environmental influences
  7. Ignition sources
  8. Marking and identification
  9. Legislation, Directives and Standards
  10. Earthing and Bonding
  11. Protection methods in detail
  12. Ex’d’, Ex’e’, Ex’n’, Ex’p’, Ex’i’, Ex’m’, Ex’o’, Ex’q’
  13. Dust protection by enclosure
  14. Wiring systems and glanding
  15. Installation, maintenance, inspection and testing


The qualifications required for eligibility for enrolment on a CompEx course can be found in JTL925: Qualifications Criteria For Entry Onto CompEx Courses >>