Blue Silica Gel is also known as Self Indicating Silica Gel as it is prepared by impregnating White Silica gel with Cobalt Chloride present in a concentration of 0.5 to 1% weight for weight, an indicator, which provides the Blue color appearance. Self – Indicating Blue Silica Gel will adsorb moisture in exactly the same way as standard non-indicating (white) silica gel but will actually indicate when they are becoming saturated by changing their colour from blue to pink thus indicating that it has adsorbed moisture and needs to be replaced.