Potentially explosive atmospheres

Employers are obliged to ensure the health and safety of their employees in potentially explosive atmospheres. The employer must implement necessary measures to ensure that work can be safely carried out in potentially explosive atmospheres. The employer must also appropriately monitor the space using technical equipment.

The provisions of ATEX regulations apply to all employers whose employees may be exposed to an explosion hazard, excluding explosion hazards caused by explosives. The purpose of the provisions is to prevent hazards caused by potentially explosive atmospheres, protect the health and safety of employees and reduce property damage. ATEX is an abbreviation of the French words atmosphèes explosibles.

What are potentially explosive atmospheres?

Potentially explosive atmospheres are conditions that potentially contain an explosive mixture of air. Potentially explosive atmospheres may be caused by mixture with air, under atmospheric conditions, of flammable substances in the form of gases, vapours, mists or dusts.

Potentially explosive atmospheres are often present in industries, such as power production, chemical industry, pharmaceutical industry and wood processing industry, and in the manufacture, handling and storage of flammable liquids and gases.

Flammable substances

Flammable substances refer to substances which may form an explosive atmosphere. The definition of flammable substance changes depending on whether the substance is a liquid, gas or dust.

  • Flammable liquid refers to a liquid chemical with a flash point no higher than 100 °C. Examples of flammable liquids include solvents, fuels, petroleum, heating, lubricating or waste oils and varnishes.
  • Flammable gas or gas mixture has a flammable range with air at 20 °C and at atmospheric conditions. Flammable gases include liquefied gases, such as butane or propane, natural gases and combustion gases, such as carbon monoxide or methane.
  • Flammable dust refers to dust from flammable solids, such as coal, wood, aluminium, sugar, flour or cereals. For dust to cause a flammable atmosphere it must be fine enough.

Employer’s obligations related to potentially explosive atmospheres

Frequently asked questions

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