What ATEX Directive 2014/34/EU asks is "what are you placing on the market?" What ATEX 153 asks is far more personal: Who are you inside the hazardous workplace — and what are you responsible for every day?

ATEX 153 – The Self-Knowledge Directive (Formally: Directive 1999/92/EC - minimum requirements for improving the safety and health protection of workers potentially at risk from explosive atmospheres)

ATEX 153 does not define economic operators. It defines functional responsibilities inside the workplace.

Which positions are identified by ATEX 153?

ATEX 153 deliberately avoids job titles. Instead, it assigns duty obligations, which can be translated into real positions within the organisation.

1. Employer (or Operator / Duty Holder)

The unavoidable role. The Employer is the primary responsible person. Self-knowledge question:

• Are you legally responsible for the workplace?
• Do people work there under your authority?
• Do you decide whether work continues or being suspended/stopped?

If yes → you are the ATEX 153 duty holder, even if every activity is outsourced. ATEX 153 assumes:

• responsibility cannot be delegated away
• only supported

2. Persons responsible for explosion protection measures

These are the people who:

• classify places as hazardous
• assess the explosion risks
• define technical and organisational measures
• ensure prevention, avoidance, and mitigation
• evaluation of combination of measures and necessary revisions
• manage changes and deviations

They may be:

• engineers
• HSE leadership
• technical leadership
• external consultants acting under mandate

Self-knowledge question:

• Do you decide how explosion risks are controlled?

If yes → you hold Ex safety authority.

3. Persons preparing and maintaining the Explosion Protection Document (EPD)

ATEX 153 requires a written Explosion Protection Document. Whoever:

• prepares it
• updates it
• signs it
• defends it during audits or incidents

…is exercising formal responsibility, regardless of job title. Self-knowledge test:

• If the EPD is wrong, who must explain why?

Note: That person is never "just a consultant". In some countries it has been defined by the national law who can prepare and maintain it, but in many not at all.

And now the critical one: the Ex Coordinator

Is "Ex Coordinator" defined in ATEX 153?

No — and that is the key insight (but the duty of coordination is defined in Article 6).

The Ex Coordinator is not a legal role in the directive. It is a guideline-driven, best-practice role, described in:

• ATEX Guidelines
• national policies, law and practice
• IEC 60079-10 / -14 / -17 logic
• Ex hazardous industry best practice

What is the Ex Coordinator in reality?

The Ex Coordinator exists because ATEX 153 responsibilities are aligned. The Ex Coordinator:

• connects zoning, equipment, procedures, maintenance
• ensures assumptions remain valid over time
• coordinates implementation, changes, deviations, and findings
• acts as the memory of the explosion protection concept

Self-knowledge question:

• Who notices when small changes and deviations accumulate into major risk?

That person is the Ex Coordinator, whether named or not.

Just saying...

Many organisations think: "We don't have an Ex Coordinator."

ATEX 153' reality

Then several people are acting as one — without knowing it. That is one of the most common root causes of explosion incidents.

ATEX 153 Roles – A Self-Knowledge Map

Reality	Legal status
Employer / Operator	Explicitly defined
Explosion protection decision-maker	Implicitly required
EPD author / owner	Explicit obligation
Ex Coordinator	Not named, but functionally unavoidable

The ATEX 153 Self-Knowledge Test

Ask yourself:

1. Who suspends/stops work if Ex conditions are compromised?
2. Who updates the EPD after significant modifications?
3. Who decides whether a change or deviation is acceptable?
4. Who connects zoning, equipment, inspection, and maintenance?
5. Who should explain the protection concept after an incident occurred?

That person exists in every hazardous plant concerned. ATEX 153 simply assumes you know who it is.

Key Insight (very important)

Explosion protection fails most often not because Ex equipment is wrong, but because ATEX 153 roles are unclear, not well defined.

Note: the same content and definition of role (Ex Coordinator) is valid in any other Ex scheme and regime. Ex compliance has to be co-ordinated and well managed.

Keep up the good work!

Arpad
veress@exprofessional.com