For the purposes of this Section, materials are divided into four classifications or ratings based on the degree of fire and explosive hazard. The rating of liquids is established by specified open cup flash points as set forth in this Section, and the Board of Standards and Appeals shall determine the rating of solids under this Section.

(a)        Class I includes slow burning to moderate burning materials. This shall include all liquids with an open cup flash point of 182 degrees F. or more.

(b)        Class II includes free burning to intense burning materials. This shall include all liquids with an open cup flash point between 100 and 182 degrees F.

(c)        Class III includes materials which produce flammable or explosive vapors or gases under ordinary weather temperature. This shall include all liquids with an open cup flash point of less than 100 degrees F.

(d)        Class IV includes materials which decompose by detonation, including but not limited to all primary explosives such as lead azide, lead styphnate, fulminates, and tetracene; all high explosives such as TNT, RDX, HMX, PETN, and picric acid; propellants and components thereof, such as nitrocellulose, black powder, boron hydrides, hydrazine, and its derivatives; pyrotechnics and fireworks such as magnesium powder, potassium chlorate and potassium nitrate; blasting explosives such as dynamite and nitroglycerine; unstable organic compounds such as acetylides, tetrazoles and ozonides; and strong oxidizing agents such as perchloric acid, perchlorates, chlorates, chlorites, or hydrogen peroxide in concentrations greater than 35 percent.