ATEX Assessment

ATEX Assessment

An ATEX Assessment is a structured evaluation of workplace risks associated with explosive atmospheres. It ensures compliance with the ATEX Directives and the UK’s equivalent regulations following Brexit.

In the UK, the key legal frameworks are:

• Dangerous Substances and Explosive Atmospheres Regulations 2002 (DSEAR) – implementing the requirements of the ATEX Directives.
• ATEX 137 (Directive 99/92/EC) – relating to worker protection (implemented through DSEAR).
• ATEX 95 (Directive 94/9/EC) – relating to equipment used in explosive atmospheres (replaced by EU Directive 2014/34/EU; in the UK, this is now managed under UKCA/UKEX marking requirements).

What is ATEX Assessment

An ATEX assessment is the process of identifying and controlling risks where flammable gases, vapours, mists, or combustible dusts may create an explosive atmosphere. It is a legal requirement under DSEAR for any workplace handling or storing dangerous substances.

Key Steps in an ATEX Assessment

1. Identify Dangerous Substances

• Flammable gases, vapours, liquids, dusts, or solids.
• Consider sources of release (storage, transfer, leaks, spills).

2. Identify Potential for Explosive Atmospheres

• Conditions under which a substance can form an ignitable mixture with air.
• Frequency and duration of these conditions.

3. Identify Potential Ignition Sources

• Hot surfaces, electrical equipment, static discharge, friction, open flames, mechanical sparks, etc.

4. Zoning of Hazardous Areas (ATEX Zoning)

Gas/Vapour Zones:

• Zone 0: Constant presence of explosive atmosphere.
• Zone 1: Likely presence in normal operation.
• Zone 2: Unlikely or infrequent presence.

Dust Zones:

• Zone 20: Constant presence of combustible dust.
• Zone 21: Likely presence in normal operation.
• Zone 22: Unlikely or infrequent presence.

5. Assessment of Equipment and Protective Systems

• Equipment must be appropriately certified for the relevant zone (ATEX/UKEX-rated).

6. Risk Control Measures

• Elimination or substitution of dangerous substances where possible.
• Ventilation and containment systems.
• Control of ignition sources.
• Use of intrinsically safe equipment.
• Safe systems of work, training, and emergency planning.

7. Documentation – Explosion Protection Document (EPD)

• Under DSEAR, employers must produce and maintain an EPD, setting out:
• Identified risks.
• Hazardous area classification (zoning).
• Control measures in place.
• Maintenance, inspection, and training arrangements.

Outcomes of an ATEX Assessment

• Identification of hazardous zones and risks.
• Confirmation of compliance with DSEAR and ATEX requirements.
• Recommendations for risk reduction and safe working practices.
• Evidence for regulators (HSE, insurers, etc.) that risks are being managed.