If you are hiring electrical or instrumentation technicians for hazardous area work in oil and gas, petrochemical, or any facility with explosive atmospheres, CompEx is the certification you need to name in your role brief. Not "hazardous area experience." Not "ATEX awareness." CompEx.
What CompEx is
CompEx stands for Competency in Explosive Atmospheres. It is a personnel competency certification accredited by UKAS to ISO/IEC 17024, aligning with IEC 60079. Major operators including Saudi Aramco, Shell, BP, TotalEnergies, and Equinor require or prefer CompEx.
It is not a one-day awareness course. It is a multi-day programme combining classroom instruction with hands-on practical assessment in simulated hazardous area environments.
The units that matter for your brief
This is where most role briefs go wrong. CompEx is modular. Ex01 to Ex04 are the core units for electrical and instrumentation technicians in gas and vapour hazardous areas. Ex05 to Ex06 cover combustible dust atmospheres. Ex11 covers mechanical technicians. Ex14 is for the Responsible Person. ExF is awareness-level only.
Why a vague brief creates problems
When a role brief says "CompEx required" without specifying units, the agency submits candidates with any CompEx unit for roles that require Ex01-Ex04. Candidates with dust-atmosphere certification get submitted for gas-and-vapour roles. The client discovers the mismatch during the interview, or worse, after deployment.
How to write the brief
If you need an electrical technician for gas and vapour hazardous area work, write: "CompEx Ex01-Ex04 (Gas and Vapours) required. Current certification with valid expiry date."
Always ask for the expiry date. CompEx certificates are valid for five years. A certificate that expired six months ago is not a valid certificate, regardless of what the CV says.
The broader point
The fix is simple: name the certification, name the specific units or levels, and require the expiry date. It takes five minutes to write a precise brief. It takes five weeks to replace a contractor who did not have the right one.