ATEX 153 ‘Worker Protection Directive’ 99/92/EC (also known as ATEX 137)

Improving the safety and health protection of workers potentially at risk from explosive atmospheres.

In addition to Product Certification there are also regulations which govern the safe operation of locations where hazardous areas occur, ensuring the safety of life and property.

DNV provides a range of services to support site operators in ensuring compliance with legislation and recognised best practice.                          

Relevant Directive or Legislation

The full title of Directive 99/92/EC is Directive on minimum requirements for improving the safety and health protection of workers potentially at risk from explosive atmospheres.  It is often also referred to as “ATEX 137” or the “ATEX Worker Protection Directive” as it refers to Article 137 of the European Treaty to provide protections to workers. Due to subsequent changes of TFEU, Article 153 is now relevant.

EU Member States have incorporated the requirements of the Directive in to national laws, in some cases incorporating other directives.  Notably DSEAR (Dangerous Substances & Explosive Atmospheres Regulations) in the United Kingdom.  As an operator of a plant or facility with a potentially explosive atmosphere you must ensure that you satisfy the requirements for worker protection in conjunction with national legislation, which may supplement or extend the basic requirements. 

Basic Technical Concepts

The Directive 99/92/EC contains a number of Articles outlining the Obligations of the Employer with respect to identification and management of risks associated with potentially explosive atmospheres.  The Directive is implemented in member states under specific local legislation which may supplement or extend the basic obligations – for this reason, the directive should always be read in conjunction with any local legislation and requirements.

Prevention of and Protection against Explosions (Article 3)

The employer must take all necessary steps to protect the workers/employees from the risks associated with a potentially explosive environment through Prevention  of the formation of Explosive Atmospheres or where that is not possible; the Avoidance of ignition sources and Mitigation of the detrimental effects of an explosion.

Assessment of Explosion Risks (Article 4)

The employer must assess the specific risks arising from the explosive atmosphere, including: likelihood and persistence of an explosive atmosphere; likelihood of active ignition sources; substances used and processes, and; the scale of anticipated effects.

General Obligations (Article 5)

The employer must take necessary measures to ensure that in working environments where explosive atmospheres can occur: that the work can be performed safely, and; appropriate supervision is in place during the presence of workers.

Duty of Coordination (Article 6)

Where workers from several employers are present in the same work environment, each employer shall be responsible for all matters under his/her control.  However, the directive is clear that the employer responsible for ‘the workplace’ in accordance with national law shall be responsible for overall coordination of all measures and employees defined in the Explosion Protection Document.

Places where Explosive Atmospheres may Occur (Article 7)

The employer is responsible for correct classification of the Hazardous Area(s) into Zones and implementing all requirements specified in the directive, particularly Annex II ‘Minimum requirements for Improving Safety’ including but not limited to Training, Procedures & Permits to Work, Explosion Protection Measures and Equipment Selection & Annex III including Compliant Signage.

Explosion Protection Document (Article 8)

The employer shall ensure that a document, referred to as the ‘Explosion Protection Document’ is created and kept current which shall demonstrate:

  • The Explosion Risks have been determined and assessed
  • Adequate measures will be taken to achieve the aims of the directive
  • Those areas which have been classified into zones in accordance with Annex I
  • Those places where the minimum requirements in Annex II will apply
  • That the workplace and equipment, including warning devices are designed, operated and maintained with due regard for safety
  • That in accordance with Directive 2009/104/EC arrangement have been made for the safe use of equipment

The Explosion Protection Document shall be created prior to commencement of work and updated in the event of any changes, extensions or conversions.

What services can DNV provide?

Provide employers with professional expert and technical support with their safe implementation of 99/92/EC Worker Protection Directive including, but not limited to:

  • Necessary risk assessment(s) based on best practice frameworks
  • Laboratory testing of material properties needed for explosion risk assessment and effective design of explosion safety measures
  • HAC – preparation of Hazardous Area Classification documentation (perform Zoning)
  • EPD – preparation or review of the Explosion Protection Document
  • On-site inspection with reporting on findings that could compromise explosion safety
  • Professional assistance at specific steps related to explosion safety during the HAZOP analysis
  • Assessment of design documentation compliance relating to selection of equipment and protective systems in the design phase of the new project, or modifications at the existing one
  • Compliance verification on electrical installations and protective measures
  • Compliance verification on non-electrical equipment and installations
  • Assessment of potential sources of ignition related to non-electrical equipment and installations (e.g. static electricity, hot surfaces, friction sparking)
  • Compliance verification on measures to avoid or mitigate the possibility of explosive atmosphere formation (e.g. inertion, ventilation, pressurization)
  • Compliance verification on protective systems and measures for mitigation of explosion effects (e.g. assessment of explosion resistant design, explosion relief, explosion suppression, prevention of explosion propagation)
  • Training of personnel working in places where explosive atmospheres may occur

Common Standards & Codes of Practice

IEC/EN 60079-10-1  Explosive atmospheres - Part 10-1: Classification of areas - Explosive gas atmospheres

IEC/EN 60079-10-2  Explosive atmospheres - Part 10-2: Classification of areas - Explosive dust atmospheres

Energy Institute Part 15 (Full title: Model code of safe practice Part 15: Area classification code for installations handling flammable fluids) – formerly called and often still referred to as IP 15 (Institute of Petroleum Part 15)

NFPA (National Fire Protection Association) 497: Recommended Practice for the Classification of Flammable Liquids, Gases, or Vapors and of Hazardous (Classified) Locations for Electrical Installations in Chemical Process Areas

More information


Directive 99/92/EC

(See also the specific national instruments of legislation for your specific jurisdiction)


Good Practice Guide for Implementation of 99/92/EC