Thermal paper does not cause cancer
The main chemical component of thermal paper is bisphenol A. Bisphenol A is a low-toxic chemical substance. It is very stable at room temperature. When it reaches a certain dose, it may cause hidden dangers such as endocrine disorders. According to national standards, thermal paper contains a small amount of color developer bisphenol A, which will volatilize quickly after contact with ordinary people, will not cause major damage, and will not cause cancer.
Thermal paper is still relatively common in our lives and has been widely used, such as shopping receipts in supermarkets, credit card purchase receipts, taxi receipts, various lottery tickets, ATM deposit and withdrawal credentials, etc. Wait, we have to come into contact with it a lot of times. In fact, only a small amount of the color-developing agent bisphenol A is contained in the thermal paper. Generally, it will volatilize soon after contacting it, and it will not cause major damage. It will not cause cancer, but pregnant women and Infants under the age of 3 should avoid contact as much as possible.
Thermal paper is a special kind of coated processed paper whose appearance is similar to ordinary white paper. The surface layer of thermal paper is smooth, which is made of ordinary paper as the paper base, and is coated with a layer of heat-sensitive chromophoric layer, which is coated on one side of the surface of ordinary paper. It is called leuco dye), which is not separated by microcapsules, and the chemical reaction is in a "latent" state. When the thermal paper encounters the hot print head, the color developer and the leuco dye at the place where the print head prints chemically reacts and changes color to form images and texts.
When the thermal paper is placed in an environment above 70°C, the thermal coating begins to change color. The reason for its discoloration also starts from its composition. There are two main thermal components in thermal paper coating: one is leuco dye or leuco dye; the other is color developer. This type of thermal paper is also called two-component chemical type thermal recording paper.
Commonly used as leuco dyes are: crystal violet lactone (CVL) of trityl phthalide system, fluoran system, leuco benzoylmethylene blue (BLMB) or spiropyran system. Commonly used as color-developing agents are: para-hydroxybenzoic acid and its esters (PHBB, PHB), salicylic acid, 2,4-dihydroxybenzoic acid or aromatic sulfones and other substances.
When the thermal paper is heated, the leuco dye and the developer react chemically to produce color, so when the thermal paper is used to receive signals on a fax machine or print directly with a thermal printer, the graphics and text are displayed. Since there are many varieties of leuco dyes, the color of the handwriting displayed is different, including blue, purple, black and so on.