silica gel

[sunfish]

I have many packets of silica gel from shoe shops.Is it useable indefinately?If not, can it be recharged by drying in a cool oven?

[trux]

There are different brands of silica gel, and some of them are quite toxic, so I would avoid stocking them in a living room or putting them into an oven. Especially the self-indicating types (blue=dry, pink=wet) and those treated with fungicides (I suspect that may be your case) are toxic or carcinogen. You will find plenty of information in Google.