For ATEX purposes, atmospheres are categorised into two classifications: “G” for explosive gas and “D” for combustible dust. A product certified for both gas and dust is marked G-D.
A new feature of the ATEX Directive is that the manufacturer now also needs a quality system in place that must be checked by the Notified Body. The audit of the manufacturing facility responsible for delivering Ex equipment is one of the three key elements in the ATEX system. The other two are the harmonised standards for equipment; and notification by the European Commission to recognise bodies and test laboratories as Notified Bodies.
North American terminology. Electrical equipment used in hazardous locations, classified according to North American rules, must be approved by an authorised body or the manufacturer.