The Bureau of Mines characterized 32 bulk samples of electric arc furnace steelmaking dust for chemical, physical, and extraction procedure (ep) toxicity properties to provide a basis for resource recovery decisions. Surface areas, densities, weight loss on drying, and semiquantitative data on 48 elements were obtained. Quantitative values for ag, al, ba, br, c (total and free), ca, cd, cl, CO, cr, cu, f, fe, k, mg, mo, na, ni, no-3, p, s (total and sulfate), si, sn, ti, V, and zn were obtained for each sample. Arsenic and selenium were determined in selected samples. The valence states of cr, fe, and zn were obtained for all samples. The ep toxicity test for hazardous waste classification resulted in 29 of the 32 dusts exceeding the criteria for listing as a hazardous waste. Leached cd, cr, and pb were the problem in each case, with selenium also high in several of the leachates. Density separation studies show a trend for zinc and lead to be more concentrated in less dense fractions and chromium in the more dense, though the extremely fine particle size (generally < 0.2 Um) will probably preclude physical separation as a viable resource recovery option.