Don’t Ignore
Aluminum Dross Regulations
Although a common material in metalcasting facilities, aluminum dross is a potentially dangerous material, and shipping and handling regulations should be considered. BRIAN COCHRAN, BRIAN P. COCHRAN & ASSOCIATES, WABASH, INDIANA
tial dangers, resulting in numerous regulations associated with shipping and handling containers of the material. Dross, a mixture of aluminum, aluminum oxides and other impurities, is the result of fluxing aluminum oxide film out of the metal before pouring the mold. If the oxides aren’t fluxed out, casting defects and component failure can result. All forms of aluminum dross contain aluminum car-
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any metalcasting facilities regu- larly handle aluminum dross. But some would be surprised that wet aluminum dross has poten-
bides and nitrides, as well as small globules of aluminum alloy. Aluminum dross when cold and dry can cause irrita- tion to the eyes, ears, nose and throat of the handler. When wet and confined in an enclosed storage area or container, the material can create noxious amounts of ammonia and explosive quantities of methane and hydrogen (see sidebar “Chemical Reactions” for more info). Additionally, enclosed dross produces significant heat, which can lead to a thermite reaction (Fig. 1) and temperatures of 3,000F (1,648C). Typically, dross is put into containers and shipped to a recy-
cler, who refines the dross to recover the entrapped aluminum alloy as reusable metal. Te U.S. Department of Transportation (DOT) and Occupational Safety and Health Administration (OSHA), have categorized aluminum dross as a class 4.3 haz- ardous material, “Hazardous When Wet.” Tis regulation covers materials that, when wet or in contact with water, can become spontaneously flammable or give off flammable or toxic gas at a rate greater than 1 liter per kilogram per hour. Because of this categorization, both metalcasting facilities
Fig. 1. Shown is the heat reaction inside a pile of aluminum dross spontaneously combusting.
and carriers of aluminum dross are subject to the regulations for shipping and handling aluminum dross found in the Code of Federal Regulations, CFR, Title 49, Transporta- tion, parts 171-180. Even though an outside freight carrier may transport the material, it is still the responsibility of the metalcasting facility to make sure it is properly handled and labeled in English on shipping papers and containers as “Aluminum Melting By-Products.” Improper storage or shipping of aluminum dross can lead to civil and criminal penalties. Civil penalties range up to
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