NFPA 484-2002 Standard for Combustible Metals, Metal Powders, and Metal Dusts.
4.1.2 Building Construction. All buildings used for the manufacture, packing, or loading for shipment of aluminum powders shall be con- structed of noncombustible materials throughout and shall have nonload-bearing walls. The buildings specified in shall be designed so that all internal surfaces are readily accessible to facilitate cleaning. All walls ofareas where fugitive dust can be produced shall have a smooth finish and shall be sealed so as to leave no interior or exterior voids where aluminum powder can infil- trate and accumulate. The annulus ofall pipe, conduit, and ventilation pen- etrations shall be sealed. Floors shall be hard surfaced and shall be installed with a minimum number ofjoints in which aluminum powder or dust can collect. The requirements of shall also apply to el- evated platforms, balconies, floors, or gratings. Roofs ofbuildings that house combustible aluminum dust–producing operations shall be supported on girders or structural members designed to minimize surfaces on which dust can collect. Where surfaces on which dustcan collectare unavoid- ably present, they shall be covered by a smooth concrete, plas- ter, or noncombustible mastic fillet having a minimum slope of55 degrees to the horizontal. Roofdecks and basements shall be watertight.* Explosion venting shall be provided for buildings where aluminum powder is processed. Deflagration venting shall not be required for areas where aluminum powder is only stored or moved in covered or sealed containers.* Powder-manufacturing areas shall be classified, where applicable, in accordance withArticle 500 ofNFPA70, National ElectricalCode. Offices and similar areas within the aluminum powder–manufacturing building that are segregated and rea- sonably free from dust shall not be classified. Control equipment meeting the requirements of NFPA496, StandardforPurgedandPressurizedEnclosures forElec- tricalEquipment, shall be permitted. One or more remotely located control stations shall be provided to allow the safe and selective shutdown of pro- cess equipment in an emergency. All manufacturing buildings shall be provided with emergency lighting systems in accordance with Section 7.9 of NFPA101, LifeSafety Code. Preventive maintenance for electrical equipment shall be established commensurate with the environment and conditions. Electrical equipment shall be inspected and cleaned at least once each year or more frequently ifconditions warrant. Flashlights and other portable electrical equipment shall be listed for the locations where they are used.NFPA 484 pdf download.