10/07/2012
Directive 9/9/EC defines an explosive atmosphere as a mixture of:
a) Flammable substances – gases, vapours, mists or dusts
b) With air
c) Under specific atmospheric conditions
d) In which, after ignition has occurred, combustion spreads to the entire flammable mixture
(NB: with regard to dust, it may be that not all dust is combusted after ignition has occurred)