Group H occupancies include buildings or structures, or portions thereof, that involve the manufacturing, processing, generation or storage of materials that constitute a high fire, explosion, or health hazard. There are eight divisions in this Group:1.Division 1 – Occupancies with a quantity of material in the building exceeding regulation set limits and that present a high explosion hazard, such as blasting agents, fireworks, black powder, certain oxidizers and detonatable unstable (reactive) materials, and other materials (refer to Code for more details).2.Division 2 – Occupancies where combustible dust is manufactured, used, or generated in such a manner that concentrations and conditions creates fire or explosion potential, or occupancies where materials exceeding regulation set limits present a moderate explosion hazard or a hazard from accelerated burning, such as some organic peroxides, pyrophoric gases, flammable or oxidizing gases, some nondetonatable unstable (reactive) materials, and other materials (refer to Code for more details).3.Division 3 – Occupancies where flammable solids, other than combustible dust, are manufactured, used or generated, or occupancies where materials exceeding regulation set limits present a high physical hazard, such as some organic peroxides and oxidizers, pyrophoric liquids or solids, flammable solids in storage, flammable or oxidizing cryogenic fluids, and other materials (refer to Code for more details).4.Division 4 – Repair garages not classified as Group S, Division 3 Occupancies.5.Division 5 – Aircraft repair hangars not classified as Group S, Division 5 Occupancies, and heliports.6.Division 6 – Semiconductor fabrication facilities and comparable research and development areas in which hazardous production materials (HPM) are used and the aggregate quantity of materials exceeds those set by regulations. Such facilities and areas shall be designed and constructed following a different set of regulations.7.Division 7 – Occupancies having quantities of materials in excess of those set by regulations, and that are health hazards, such as corrosives (except stationary lead-acid battery systems), toxic and highly toxic materials, irritants, sensitizers, and other health hazards (refer to Code).8.Division 8 – Laboratories and similar areas used for scientific experimentation or research having quantities of materials not in excess of those set by regulations, and not otherwise classified as Group B, Division 2 Occupancies (refer to Code for more details).