Silica Gel Desiccant; White, Blue or Orange?
White silica gel is a non-indicating silica gel. It means that when the silica gel adsorbs moisture, it will continue to be white. This kind of silica gel is commonly used in packet. White silica gel is a kind of gel you find in the small packets when you buy some products.
Blue silica gel has cobalt chloride, which allows the blue silica gel change its color to pink when it reached its maximized adsorption capacity. Once pink it can be reactivated with heat to dry out the moisture. When it turns blue again, it’s ready to use. Do not use blue silica gel around food since the cobalt chloride is poisonous.
Orange silica gel has methyl violet which is capable of changing from orange to green, or orange to colorless. It is also toxic and potentially poisonous, even though it does have some medicinal merits. Like blue silica gel, once the color changes to indicate maximum adsorption, it can be reactivated with heat to dry out the moisture. When it turns orange again, it’s ready to use.
