This European Standard applies to the silica fume which is a by-product of the smelting process used to produce silicon metal and ferro-silicon alloys.This part of EN 13263 gives requirements for chemical and physical properties for silica fume to be used as a type II addition in concrete conforming to EN 206-1, or in mortars, grouts and other mixes. This part of EN 13263 also states conformity criteria and related rules. .EN 13263 does not give rules for the use of silica fume in concrete. Some rules are given in EN 206-1.NOTE 1 Supplementary rules related to the use of silica fume in concrete may be given in non conflicting national standards for concrete. NOTE 2 EN 206-1 (5.2.5.1 in the 2000 edition) provides conditions for national acceptance of silica fumes coming from calcium silicon alloys production or other silica fumes, not conforming completely to EN 13263, as type II additions for use in concrete.