Humidity indicator card is a convenient and cheap safe method to detect environmental humidity. Users can quickly judge the humidity and the effect of desiccant in the product package by the color on the card. If the humidity of the package exceeds or equals the humidity value, the corresponding point on the card will change from the dry color to the hygroscopic color, so that the effect of the desiccant can be easily known. The 2004 EU Environmental Regulation (2004/73/EC) has classified cobalt chloride as a class II carcinogen and now bans the use of cobalt-containing humidity indicator CARDS, which are required for all products exported to EU countries. So the ubiquitous humidity indicator CARDS (from blue to pink), which are based on cobalt chloride, will soon be banned. For example, SONY prohibits the use of cobalt chloride humidity indicator CARDS and other products on SS00259) version 8. In order to meet the relevant laws and regulations and environmental protection requirements, Weller, the company set up special humidity card business, developed to drench membrane humidity on the back card, humidity card behind the film protection, avoid the customer's products, direct contact with humidity card potion won't cause pollution to the customer product, accord with the requirement of industrial product, is well received by the customers. A new generation of environmental humidity indicator card (Type II, type III) is being developed. The daily output of this series of products is more than 100,000. It conforms to THE European Union RoHS directive (excluding it) and has passed CTI and SGS tests. The color of the instruction changes significantly, the workmanship is excellent and the use is convenient.