What terms do testing agencies use?

What are the correct terms that nationally recognized Testing agencies, Factory Mutual, Underwriters Laboratories, Mine Safety and Health Association and the Canadian Standards Association use?

Nationally recognized Testing agencies, Factory Mutual (FM), Underwriters Laboratories (UL), Mine Safety and Health Association and the Canadian Standards Association have all adapted the following terms.

Nature of Hazard is the Class:
Class I (Flammable gases or Vapors)
Class II (Combustible Dust)
Class III (Fibers)

Probability of Hazard:
Division 1 - The hazard is present continually or intermittently.
Division 2 - Present under abnormal conditions only.

Zone 0 Present continually
Zone 1 Present intermittently
Zone 2 Present under abnormal conditions only.

Specific Hazard (list in order of severity and an example):
Group A Acetylene
Group B Hydrogen or equal
Group C Ethylene, Hydrogen Sulfide, Cyclopropane, Ethyl, Ether, or equal
Group D Propane, Acetone, Alcohol, Natural Gas, Butane, Gasoline, or equal
Group E Metal Dust
Group F Carbon Black, Coal
Group G Flour, Starch, Dairy powders, Dried Hay, or equal