5 day course

CompEx Ex01 to Ex04 (Gas and Vapours)

Due to the practical elements of this course and the specialist equipment required, it is delivered at our Rotherham training centre only. 

CompEx is the national training and assessment scheme for electro technical crafts personnel who work in potentially explosive atmospheres, such as on and off-shore Oil and Gas Pharmaceuticals, Energy and Chemical industries.

It is a national joint training initiative developed and implemented by the Engineering Equipment and Material Users Association (EEMUA) and JTL and is supported by the Health and Safety Executive.

This 5-day course aims to deliver competence based training and assessments in the selection, use, maintenance and inspection of electrical apparatus in potentially explosive atmospheres in accordance with the requirements of IEC 60079 series relevant standards.

The course includes instruction on how to read hazardous area certification, labelling and documentation. It also informs candidates about the main protection concepts, categories and levels that are applied to certified Ex electrical equipment.

The course is split into 3 days of guided learning, approximately 15-20 hours theoretical and 4-6 hours practical. Assessments are completed on days 4 and 5.

Who should take this course?

This is an intense course which is intended for practicing electrical or instrument technicians who are involved in installing, inspecting and maintaining certified Ex electrical equipment in locations where gases and vapours can potentially create a hazardous area. Delegates are required to bring photographic identification and suitable evidence to prove their competence. This ideally will be certification/letter from your employer or a JIB Gold card.

Course content

  • Area classification
  • Gas groups
  • Temperature classification
  • I P Ratings
  • Selection of equipment
  • Ignition sources
  • Legislation
  • Directives and standards
  • Earthing and Bonding
  • Ex ‘i’, Ex’d’, Ex’e’, Ex’p’, Ex’m’, Ex’n’, Ex,’o’ and Ex’q’.
  • Wiring systems and glanding
  • Installation, maintenance, inspection and testing
  • Feedback and review


Assessment Method

Assessment methods during this course cover the four separate CompEx units. Candidates must complete an online multiple-choice examination consisting of 60 questions (1.5 hours) and four practical assessments on a simulated installation (one per unit). Candidates who are successful in all elements of the assessments will receive a CompEx Certificate in Core Competence.


Not sure whether to start with the full 5 day course or take the CompEx ExF Foundation course instead? Determine which course would be best for you with the new CompEx awareness tool - 'IntroEx'. This free short assessment takes about 20 minutes to complete and provides an overview of the basic principles of potentially explosive atmospheres and safety. If you are already due to attend training, it can also be used as pre-learning material. 

Access IntroEx here



Can this course be attended online?

Due the practical exercises in the course, the training is delivered in a classroom environment and cannot be delivered virtually.

Do I have to resit the full course if I am unsuccessful in the exam?

Hopefully you will pass first time but if required you can resit the relevant assessment parts rather than having to attend the whole course again.

Do I need to bring any equipment/tools to the course?

No, Centrica will provide everything that you require.

When do I take the assessments on the course?

This will be on days 4 and 5

When will I find out if I have been successful in the end of course exam?

Results will be available 6-8 weeks after the course.

Related Courses

The following courses are also available and may complement and build upon the knowledge gained
on the CompEx Ex01 - Ex04 - Gas and Vapours course.

Our Accreditations and Affiliates

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