Silica fume is a by-product generated in an electric arc furnace during the silicon, ferrosilicon, and other metal alloy manufacturing process. Prefabrication mineral additives such as fly ash, blast furnace slag and silica fume are commonly used as binder materials to improve cement quality, and to reduce cement consumption. Especially silica fume which has a high level of long-term chemical durability is most widely used in high-performance concrete. However, Korea relied 100% on imported silica fume, which is more expensive than other admixture, until 2014. So far, many studies have been conducted on the effects and performance of silica fume used in concrete or replacement material like metakaolin and blast-furnace slag. With the construction of ferrosilicon plant in Korea, silica fume, a by-product of ferrosilicon production process, has been generated as a new industrial waste. Waste products like silica fume contain heavy metal, hence its use as admixture could increase heavy metal contents in concrete. Therefore, to evaluate the environmental hazards of silica fume, when it is assumed to have been exposed to the environment, content analysis and leaching tests for pH, loss on ignition and trace elements (CN, Cr, Cr6+, Cu, Cd, Pb, As and Hg) in silica fume were conducted. The results of pH analysis and loss on ignition test were 2.18 ~ 7.39 and 0.9 ~ 2.1%, respectively. Analysis found that levels of race elements in silica fume produced in Korea were lower than Korean standards set out for designated waste.