Complications from the interaction between EEC directives, European standards for explosion safety and the equivalent national standards

Increasingly in most European countries the majority of designs of electrical apparatus and instrumentation for potentially explosive atmospheres comply with the European Standards (ENs) for explosion safety. The Standards are referred to in the relevant EEC Directives intended to allow unimpeded movement between EEC countries. There are numerous complications which in varying degrees can result in problems which the Directives are intended in principle to overcome. The more significant of these complexities are reviewed and tentative suggestions are made for dealing with the problems with a cautious eye on 1992