The humidity indicator card is divided into Cobalt and Cobalt-free HIC: Cobalt humidity card (not in line with the EU export standards, as it is not environmental protection) : the most intuitive to judge the humidity status is from the color change.The humidity card is blue when dry. If the color inside the circle changes from blue to pink, it means that the humidity inside the package has reached or exceeded the relative humidity value of corresponding to the circle.Cobalt chloride, which was listed as a class ii carcinogen in the 2004 EU environmental regulation (2004/73/EC), is now banned on the cobalt-containing humidity indicator card and all products exported to the EU must meet the requirements of the regulation.Hence the cobalt humidity CARDS had been banned to exporting to the EU. Therefore, cobalt-free humidity indicator card came into being. Cobalt-free humidity indicator card is a convenient ,cheap and safe method to detect environmental humidity. Users can quickly judge the humidity and desiccant effect in product packaging by the color on the card.If the humidity in the package exceeds or is equal to this value, the corresponding point on the card will change from a dry color to a hygroscopic color, so that the effect of the desiccant can be easily known.