NFPA 497A : 1992

Chapter 1 General
1.1 Scope
1.2 Purpose
1.3 National Electrical Code criteria
Chapter 2 Basic considerations
2.1 National Electrical Code criteria
2.2 Conditions necessary for ignition
2.3 Behavior of gases, vapors, and liquids
2.4 Division 1 classified locations
2.5 Division 2 classified locations
2.6 Nonclassified locations
2.7 Extent of classified location
Chapter 3 Determining the degree and extent of
            hazardous (classified) locations
3.1 Diagrams and recommendations
3.2 Bases for recommendations
3.3 Procedure for classifying locations
3.4 Index of classification diagrams
Chapter 4 Referenced publications
Appendix A Referenced publications
Index

Recommends steps to determine the location, type, and scope of hazards presented by electrical installations in operations where flammable or combustible liquids are processed or handled. Coverage includes nonclassified locations, extent of classified location, procedure for classifying locations, conditions necessary for ignition, and index of classification diagrams. Also gives National Electrical Code Criteria.