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Special Interest Groups

Explosive Atmospheres


The Explosive Atmospheres Special Interest Group (Ex-SIG) is responsible for promoting awareness and understanding of Ex matters. Our focus is a set of associated practices and regulations. These areas continue to develop and represent significant challenges for guidance and understanding.

The SIG is authorised to constitute working groups to help fulfil its purpose.


Members & Leadership Team

Membership is drawn from a wide spectrum including end users, regulators, vendors, contractors and consultants, so that we may represent a broad range of interests in safety related matters.  Many SIG members also belong to other professional bodies and this promotes an exchange of views and information throughout the discipline.

Additional standing or temporary working groups may be formed as sanctioned by the steering group.

Steering Committee

Chair: Harvey T. Dearden BSc CEng FIET FIMechE FInstMC FIChemE

InstMC Registered Explosive Atmospheres Engineer

Broad ranging process sector experience (40+ years) with employment through vendor (Foxboro), EPC (Costain, NNC), consultant (K&D), service (SGS), and end user companies (CEGB, AOC). Last 20+ years as independent consulting engineer (TDS). Has served as trustee and council member of InstMC, and chair of Central NW Section. Currently chair for FS-SIG and Ex-SIG committees.

Secretary & Ex Webmaster:  Peter R Morriss CEng InstMC, FIET, P.I.G.

Over 56-years’ Instrumentation and Control experience in the Petro Chemical Industry; (20 Years technical management with Shell UK and Shell International and 22 years as an Independent Consulting Engineer ) Experienced in Design, Haz Ops, MOC, Projects, Project & Maintenance Management and Specialist in Pipeline Leak Detection. Registered with the IEC for competancy for EX inspections.


Andrew Tither Exloc

Ron Sinclair SGS

R Goater HazardEx

Ian Reynolds

Ernest Kyei InstMC

Colin Ainsworth

Tal Hopkins

Dave Myler

Micheal Dorrington

Martin Hold MD HTS Group

Colin Oxton

Richard Leng

Peter Davidson

S Patel




SIG Role and Activities

  • To provide impartial advice on behalf of the Institute on Ex related matters.
  • To comment on any Ex related submissions received by the Institute,
  • To liaise as appropriate with other InstMC SIG.
  • To raise the profile of the InstMC by liaising with other bodies as appropriate
  • To organise conferences, workshops and seminars on Ex matters, and to prepare papers for publication. These may be self-initiated, by agreement with other SIG or Local Sections, or by co-sponsorship with other bodies where appropriate.
  • To oversee the Registered Explosive Atmosphere Engineer qualification and support application reviews and interviews.
  • To provide a forum for the members to meet, exchange experiences and share learning.
  • To be the guardian of InstMC publications related to Ex matters and update them as required.
  • To be a trusted point of contact with the regulators for Ex matters.


Get Involved

  • Membership of the SIG is automatically open to any individual member or Companion Company of the InstMC on application.
  • SIG members are automatically eligible to apply to fill vacancies on the steering committee.  Exceptionally*, applications will be accepted from other individuals and representatives of corporate bodies by agreement of the chair of the SIG or the chair of any of its working groups.  Individuals or companies wishing to join are invited to contact the chair, making clear whether or not they are InstMC members.  The steering committee will strive to maintain a balance of representation across relevant sectors. The other requirement is a willingness to share in the work of the SIG as opportunities arise.

* typically a widely recognised authority in the field

For more information on InstMC membership, see

Knowledge sharing is key. The EX SIG webpage is the conduit for making contacts and a LinkedIn Group is available for member-only content.




  • The running of the SIG is to be overseen by a steering group comprised of the chairs from the SIG working groups and other individuals (offering useful skills and/or additional network access) that the group sees fit to co-opt.
  • The chair of the steering group is to be elected by the group from amongst its members.
  • Each working group will have a chair nominated by its members.
  • Chairs will be elected for a period of 3 years (or the WG duration if less).  Chairs may serve two consecutive terms, but may only serve in that capacity beyond two terms if there is no other suitable and willing candidate.
  • The steering group and working groups should be limited in size to the number of people that are appropriate for them to effectively prosecute their business.  The size of working groups shall be no larger than agreed with the steering group.  If appropriate, additional members may be recruited as corresponding members of the WG.
  • The steering group will be accountable to the trustees for the expenses incurred in the management of the SIG, and budgets for the SIG are to be agreed with the CEO.
  • The steering group will be accountable to the trustees (via the Learned Society Board) for proper execution of its business in accordance with its terms of reference (which shall be agreed with the LSB).
  • Legitimate expenses may be claimed (in accordance with InstMC expenses policy) for steering group and working group management meetings, but not for meetings or events open to the wider SIG membership.
  • Criteria for eligibility to join working groups will be agreed with the steering group.  Vacancies will be advertised to the SIG membership.
  • Working Groups shall devise and implement a succession plan to ensure the appropriate balance and number of team members is maintained and that there is regular turnover of the WG membership.


If you are an experienced engineer working in the explosive atmospheres discipline, the InstMC Registered Explosive Atmospheres Engineer qualification could be the right choice for you. 

For more details click here!

To view the register of InstMC Registered Functional Safety Engineers CLICK HERE!