Fluorescent brightener is a fluorescent dye, also known as a white dye, and a complex organic compound. Its characteristic is that it can stimulate incident light to produce fluorescence, causing the dyed material to achieve a sparkling effect similar to fluorspar, making the material visible to the naked eye very white, achieving the effect of whitening.

Due to its ability to significantly improve the whiteness of paper, fluorescent brighteners are widely used in the papermaking industry. In the production process of napkins, some enterprises also use fluorescent brighteners to achieve the effect of improving whiteness.

Due to the discovery in recent years that fluorescent brighteners have carcinogenic effects and pose significant harm to human health, the use of fluorescent brighteners in the papermaking industry to manufacture food packaging paper and napkins is prohibited.

There is a simple test method for whether napkins contain fluorescent whitening agents. Soak the napkin in water for a while, then soak the filter paper strip in it and let it dry before checking under ultraviolet light. If the filter paper shows strong fluorescence, then the paper sample contains fluorescent whitening agent. It should be noted that although this method is fast, its accuracy is not good. If the amount of fluorescent whitening agent added to the paper sample is small, the inspection effect is not significant, so other methods need to be used for retesting.

Fluorescent whitening agents themselves are safe, with low acute and long-term toxicity. They do not accumulate in the human body and can also degrade in the environment. Overall, they are safe.