Silica gel is an extremely common item found in the packaging of electronics and other household items. It is placed there to keep water from forming on delicate surfaces, and is highly effective at removing moisture from the air. As such, it should be treated carefully and disposed of properly.
Silica gel can irritate the eyes, skin, respiratory system and digestive tract. This is generally mild and caused by the silica gel's ability to absorb moisture; it dries out these parts of your body, causing the irritation. If you throw away the pack containing the gel immediately, there should be no problem. The pack itself will be safe to handle. If accidentally ingested, it is non-toxic unless there is cobalt (II) chloride mixed in, but you should consult a doctor for any irritation that occurs.
Cobalt (II) chloride
Cobalt (II) chloride is used as a colour marker in many desiccants, because it is blue in the absence of water and turns pink once exposed to water. If there is any evidence of colour-changing compounds in the desiccant gel a person has ingested, contact a doctor immediately. Cobalt (II) chloride is highly toxic and will cause nausea and vomiting. It also may cause cancer, although studies are inconclusive on this and further research is being done.
Silica gel is generally safe for home use. However, people in any work area with industrial chemicals must be very careful how they dispose of silica gel. It will react with any strong acid, strong base and oxidiser, and must not be disposed of in any place where it may come in contact with such substances. If possible, immediately remove it from the site and dispose of it; silica gel is non-toxic and does not react with common chemicals, so disposing of it in a public trash bin is perfectly safe.