SILICON DIOXIDE, AMORPHOUS
Prepared at the 17th JECFA (1973), published in FNP 4 (1978) and in FNP 52 (1992). Metals and arsenic specifications revised at the 57th JECFA
(2001). An ADI 'not specified' for silicon dioxide and certain silicates, was established at the 29th JECFA (1985)
SYNONYMS Silica; INS No. 551
DEFINITION The products included under this specification are: silica aerogel (precipitated silicon dioxide), hydrated silica, "silicic acid", and dehydrated silica gel. The article of commerce can be further specified as to loss on drying and soluble ionizable salts.
Chemical names Silicon dioxide
C.A.S. number 7631-86-9
Chemical formula (SiO2)x
Formula weight 60.09 (SiO2)
Assay Silica aerogel: not less than 90% of SiO2 on the ignited basis. Hydrated silica: not less than 89% of SiO2 on the ignited basis.
DESCRIPTION Silica aerogel: a microcellular silica occurring as a fluffy powder or granules
Hydrated silica: a precipitated, hydrated silicon dioxide occurring as a fine, white, amorphous powder, or as beads or granules
FUNCTIONAL USES Anticaking agent
