It has been reported that some extremely brightly colored garments contain fluorescent brighteners, which pose potential hazards to human health. At the same time, the investigation report published by the International Food Packaging Association shows that some paper tableware still has potential safety hazards, and the outer packaging of many well-known instant noodle brands still contains fluorescent whitening agents.
What kind of substance is fluorescent whitening agent? It is a color conditioner with brightening and brightening effects. Its working principle is to absorb invisible ultraviolet light and convert it into longer-wavelength blue or purple visible light. After the blue light is released, it is superimposed with the yellow light emitted by the article to form a white light and make the article emit white light. With the increase, people can perceive the white objects to become whiter, brighter and more vivid with naked eyes.
In the textile and garment industry, the whiteness of the fiber itself often fails to meet people's requirements, especially natural fibers such as wool, silk, cotton, and hemp. Due to the difference in environment and growth cycle, the whiteness of fibers varies greatly, especially white fibers, which slightly absorb the blue light in the visible light, resulting in insufficient blueness, making the white fibers look slightly yellow, giving people an old look sense.
For this reason, people add fluorescent brighteners in detergents or textile finishing processes to achieve the purpose of making clothes brighter. Now, optical brighteners are widely used in textiles, papermaking, washing, plastics, coatings, leather and many other fields.