Explosive Atmosphere and Safety Characteristics

The properties of an explosive atmosphere are characterized essentially by the properties of the combustible substances or substance mixtures and by their 

The further assessment refers essentially to explosive atmospheres consisting of air and combustible gases, vapours and/or mists. Explosive atmospheres, which consist of air and combustible dusts are normally not relevant for vacuum pumps and are not assessed here. 

To form an explosive atmosphere the combustible substances must finely dispersed in air. Gases and vapours have mostly this ability. Mists, however, must form appropriately fine droplets so that a sufficiently great effective surface is maintained. 

For a better assessment of the hazardousness of an explosive atmosphere, its properties are described by so-called safety characteristics. Knowledge of these safety characteristics allows a reaUzation of appropriate measures for the avoidance of an explosive atmosphere. 

Safety characteristics are not physicochemical material constants. However, they allow quantitative statements regarding the hazard potential that can result from an explosive atmosphere. They are the bases for the specification of measures for the fire and explosion protection. 

---