Dust (Ex05 – Ex06)

The qualification for competency in working with dusts in hazardous environments.

Dust (Ex05 – Ex06)

The CompEx Dust qualification has been designed for practicing electrical or instrumentation technicians who work in hazardous locations where combustible dust, fibres or flyings can form an explosive atmosphere.


This qualification is suitable for electrotechnical personnel who work on the physical installation and assembly of new ‘Ex’ equipment and perform preventive maintenance and inspections on previously installed equipment in hazardous dust atmospheres.

Entry requirements:

  • Practicing competent electrical operatives
  • Practicing competent instrument operatives
  • Electrical/instrument engineers with previous practical experience
  • Prior CompEx certification supported by employer sponsored letter


3 days


  • 1.5 days of guided learning (theoretical 6-8 hours, practical 2-4 hours)
  • 1.5 days assessment

The Ex05 and Ex06 units confirm the core competence of electrotechnical workers using electrical and instrumentation equipment in locations where potentially hazardous dust atmospheres may exist.

The qualification consists of two units that cover the minimum requirements for the safe working practices that should be followed when working in hazardous dust locations.

Candidates will learn what considerations must be given to areas that contain potentially explosive or flammable atmospheres and the factors used to classify their location.

The course includes instruction on how to read hazardous area certification, labelling and documentation relating to dust factors that need to be considered when managing dust clouds and layers. It also covers the main protection concepts, categories and levels that are applied to certified Ex electrical equipment.

Successful candidates will demonstrate the required knowledge and skills as laid out in the IEC 60079 series of standards and the relevant national standards and directives. The Dust qualification identifies with several IEC 60079 Explosive Atmosphere Standards and is mainly focused on the minimum specifications laid out in IEC60079:0, IEC60079:10.2, IEC60079:14 and IEC60079:17.

This qualification can be used to supplement the CompEx Ex01-Ex04 Gas and Vapour qualification or undertaken as a stand-alone course. Ex05 and Ex06 can also be completed in combination with other CompEx qualifications as part of a continuing professional development plan.

Key learning objectives

Candidates that successfully complete the Ex05-Ex05 qualification will be able to:

  • Identify the correct national regulations, directives and IEC standards which are applicable to hazardous dust locations.
  • Identify the correct criteria and descriptors used to classify a hazardous dust location.
  • Recognise the correct characteristics of common hazardous dust, fibres and flyings – i.e. combustible, conductive and non-conductive.
  • Demonstrate an underpinning knowledge of how Ex electrical equipment is certified, including Ex i ,iD, ‘m’, ‘p’, ‘pD’, ‘t’, ‘tD’, ‘d’, ‘e’, ‘m’, ‘o’, ‘q’, ‘s’, how it maintains its protection concept and how it is to be selected, installed, inspected and maintained.
  • Identify the correct test value readings for IS and non-IS installations and equipment.
  • Use IEC inspection table 1 and inspect pre-installed Ex’d’, ‘e’ and ‘n’, ‘t’, ‘tD’ electrical equipment.
  • Interpret Intrinsically Safe (IS) documentation.
  • Use IEC inspection table 2 and inspect pre-installed certified, non-certified, simple and associated apparatus on a pre-installed intrinsically safe installation.
  • Identify and record faults at the correct grade of inspection.
  • Recommend the correct remedial action and IEC inspection code for each fault identified.
  • Recognise the need to prove an isolation on electrical equipment prior to carrying out a detailed inspection.
  • Use the correct documentation.

Qualification details

Candidates who are successful in both the theory and practical assessments will receive a CompEx Certificate in Core Competence. 


Assessment is undertaken using both practical assessments and an examination that covers the two separate CompEx units.


Candidates must undertake a multiple-choice examination that consists of 60 questions answered over 1.5 hours.

Practical assessments:

Candidates are required to undertake four practical assessments:

  • Ex05a assessment non-IS installation – 2 hours
  • Ex05b assessment IS installation – 1 hour 45 minutes
  • Ex06a assessment – Inspection and maintenance of non-IS electrical equipment – 1 hour 20 minutes
  • Ex06b assessment – Inspection and maintenance of IS equipment – 65 minutes

Find a centre

Find your nearest licensed CompEx centre and get full contact details using our simple map facility.

Retain certification

Achieving CompEx core competency is essential for practitioners who work in potentially explosive environments, but competency must be maintained following certification.


The CompEx resource centre provides all the essential forms, documentation and downloads that you may need for CompEx training and registration

Applicable industries:

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