A quick guide to the ATEX 137 Workplace Directive

Definition

An "explosive atmosphere" is defined in ATEX 137 as a mixture of air and flammable gases, vapors, mists, or dusts in which, after ignition, combustion spreads to the entire unburned mixture.

However, the directive does not apply to certain areas and operations covered by other regulations, including:

 

• Areas used directly for medical treatment of patients
• Use of appliances burning gaseous fuels
• The manufacture, handling, use, storage, and transport of explosives or chemically unstable substances
• Mineral-extracting industries 
• Transport by land, water, and air (except means of transport intended for use in a potentially explosive atmosphere)

What does ATEX 137 require?

Explosion Protection Document

Employers must prepare documentation that:

• Identifies and assesses explosion risks

• Describes the safety measures in place

• Includes zone classification (Zone 0/1/2 for gas, Zone 20/21/22 for dust)

• Outlines procedures for training, work permits, and maintenance

• Is updated whenever significant changes occur

Training and Competence

Anyone working in potentially explosive areas must receive:

• Training on explosion risks and safe use of equipment

• Information on protective measures and emergency response

• Documented and regularly refreshed competence

Maintenance and Inspection

• Equipment must be maintained and inspected per the manufacturer’s instructions and risk category

• The inspection frequency must be documented

• Equipment must be marked with CE and Ex symbols per the ATEX directive

• Evidence must show that the equipment is suitable for the ATEX zone in which it is used

  
  

Zone classification

Workplaces must be divided into zones based on risk:

• Gas: Zone 0 (continuous), Zone 1 (likely), Zone 2 (rare)

• Dust: Zone 20, 21, 22 (same logic)

Equipment must be approved and categorized for use in its designated zone.

 

ATEX 95 – requirements for equipment in explosive atmospheres

While ATEX 137 applies to workplaces, ATEX 95 (Directive 2014/34/EU) applies to manufacturers and suppliers of equipment intended for use in explosive atmospheres.

Equipment must:

• Be CE marked and include the Ex symbol
• Come with a declaration of conformity
• Be suitable for the specific zone classification and type of explosive atmosphere (gas or dust)

This includes certain types of loose equipment such as slings, hoists, tools, and components if they pose a potential ignition source.

Whether you are purchasing or supplying equipment, it's your responsibility to ensure it's properly certified and documented.

Are you a manufacturer or supplier? Read our quick guide to ATEX 95 here. 

 

How Onix Work helps

Onix Work helps you comply with ATEX 137 by digitizing documentation and making safety information accessible when and where it matters.

• Store explosion protection documents centrally
• Link Ex marking and zone data to each piece of equipment
• Track maintenance intervals and receive reminders
• Upload certificates and declarations for CE/Ex compliance
• Access data via QR, RFID or NFC directly from the equipment (with Onix Tags)
• Easily share documentation with customers, auditors, or authorities