Silica gel desiccant is a highly active adsorption material.It is usually made of reacting with sodium silicate an sulfuric acid, aging as well as acid bubble.
It is insoluble in water and any solvents.Non-poisonous and tasteless, chemical stability.
It won't react with any material except alkli and hydrofluoric acid.
Standard white silica gel is referred to as being non-indicating. As absorbs moisture it remains physically unchanged. Non-indicating silica gel is both cheap and effective, available loose in bulk packs or packed in sachets.