ISA S12.1 : 1991

1. Purpose
2. Scope
3. Definitions
4. Area (location) classification
4.1 North American methods
4.2 European methods
4.3 Additional background information
5. Protection techniques for electrical apparatus in
     hazardous (classified) locations
5.1 Explosion confinement
5.2 Isolation
5.3 Energy release limitation
5.4 Other methods of protection
5.5 Summary of protection techniques
6. Wiring methods for hazardous (classified) locations
6.1 Conduit system
6.2 Cable systems
6.3 Comparison of the installation systems
6.4 Comparisons of wiring methods
7. Grounding and bonding practices
8. Maintenance practices
Appendices
A. Acronyms
B. References
C. Listing of worldwide codes, guides, and standards
D. Listing of worldwide installation requirements

Gives definitions and information on protection techniques, terminology, and the installation of electrical instruments in hazardous (classified) locations and provides an introduction and basic background to the ISA SP12, Electrical Safety, series of publications and committee activities. Gives general guidelines for the safe design, installation, and maintenance of electrical instrument systems using appropriate means to prevent ignition of flammable gases and vapors, flammable liquids, combustible dusts, or ignitable fibers or flyings.