Explosion Protection (ATEX)
Explosion protection comprises primary, secondary and constructional measures used to prevent the simultaneous occurrence of an explosive atmosphere and an effective ignition source in hazardous areas, or to limit the consequences if it occurs.
Conditions for an explosion
An explosion in an industrial plant requires the simultaneous presence of a combustible gas, vapour or dust at a sufficient concentration, oxygen, and an effective ignition source. Hazardous areas are therefore classified into zones based on the frequency and duration of an explosive atmosphere, which in turn determines which electrical and mechanical equipment may be used there.
Protection measures
Primary explosion protection avoids the explosive atmosphere itself, for example through inerting, extraction or concentration limits; secondary explosion protection eliminates or controls ignition sources, including through certified Ex-rated equipment and intrinsically safe barriers for signal transmission. Where neither can be fully guaranteed, constructional explosion protection – explosion venting, suppression or isolation – limits the consequences for plant and building.
Insurance relevance
Because explosions frequently trigger secondary fires and lengthy business interruption in addition to direct property damage, evidence of an up-to-date zone classification and a matching explosion protection document is central to underwriting facilities handling combustible dusts, gases or solvents. Missing or outdated documentation is treated as a clear warning sign during a risk survey.
Legal basis
- EU: Directive 2014/34/EU (ATEX Directive) – Equipment and Protective Systems for Use in Potentially Explosive Atmospheres
Standards and codes
- VdS 6016 – Intrinsically Safe Barriers, Requirements and Test Methods