Common synonyms : Silica gel beads, silica self-indicating gel
Formula : SiO2
Physical properties : Form: off-white, pink or blue solid
Stability: Stable; absorbs moisture from the air
Principal hazards : *** Silica gel is used to absorb water from gases. The gel itself is comparatively harmless, although silica dust is harmful if inhaled. However, silica gel often contains a small amount of an added chemical to indicate whether the gel is still effective at absorbing water. This indicator may be cobalt (II) chloride, which changes from blue when the product is dry, to pink when it is nearly exhausted. Cobalt compounds are suspected of being carcinogenic, and may cause sensitization or an allergic reaction, so care should be taken that silica gel is not inhaled.
Safe handling : Wear safety glasses. Work in a well ventilated area. If the product is dusty, handle only in a fume cupboard.
Emergency : Eye contact: Immediately flush the eye with water. If irritation persists, call for medical help.
Skin contact: Wash off with soap and water.
If swallowed: Call for medical help.
Disposal : Store for later disposal as solid waste.
Protective equipment: Safety glasses.
Further information : Silica gel
Cobalt (II) chloride
Chemicals in the HSci database
More extensive safety data