Foreword
Introduction
1 Scope
2 Normative references
3 Terms and definitions
4 General requirements
5 Specific requirements
6 Verification and tests
7 Documentation and instructions
8 Marking
Annex A (informative) Working principles and determination
        of the effectiveness of a flow restricted enclosure
Annex B (normative) Calculation of the effectiveness of flow
        restricted enclosures
Annex C (informative) Duration and frequency of occurrence of
        explosive atmosphere in areas where category 2 and 3
        equipment is used
Annex ZA (informative) Clauses of this European Standard
         addressing essential requirements or other provisions
         of EU Directives