ATEX ZONES

ATEX directives

Protecting users in explosive atmospheres (ATEX)

An EXplosive ATmosphere (ATEX) is a zone in which one or more flammable substances (gas, vapour or dust) are suspended. In the event of an electrostatic spark or electrical discharge, the mixture ignites and may cause an explosion.

Managing hazards in explosive atmospheres

Work in these zones is regulated by two European Directives:

1999/92/EC, which defines minimum requirements for worker safety,
94/9/EC on equipment and protective systems.

One of the aims of these regulations is to ensure that all equipment used in ATEX zones does not cause sparks. Although these directives do not apply to PPE, they do affect them. PPE must therefore be designed and manufactured in such a way as to prevent sparking.

PPE requirements for ATEX zones

The requirements for PPE used in ATEX zones are still evolving, but currently:

They must be made of antistatic fabric and allow electrostatic charges to dissipate.
Also, the garment must be in contact with the skin (wrist, collar, etc.), either directly or via connectors (wrist strap, ankle strap, etc.) if the contact is insufficient.
In order to make contact with earth, the person wearing the electrostatically dissipative protective clothing must be suitably earthed; the resistance between the person and earth must be less than 108 Ω.
They must be made of flame-retardant fabric.
For example, PPE must be EN ISO 14116 or EN ISO 11612 approved, to provide the wearer with optimum protection against thermal hazards in the event of an explosion.