For fluorescent and fluorescent whitening agents, people usually misunderstood it.
In fact, fluorescent substances are not harmful, and without fluorescence substances are not harmless. Fluorescence is not necessarily related to toxic or non-toxic. People are not afraid of fluorescence, but fluorescent brighteners.
When we talk about fluorescence, fireflies in the night always appear in our minds, and that is the most wonderful scene in our childhood memories. In fact, fluorescence is only a physical phenomenon of cold luminescence. When it absorbs incident light of a certain wavelength (usually ultraviolet or X-rays), it emits longer-wavelength outgoing light (usually visible light). For example, absorbing blue light emits green light, absorbing green light emits red light, and the most common is absorbing ultraviolet light to emit blue light. And once the incident light stops, the phenomenon of luminescence will disappear with it.
Fluorescent brighteners have been misunderstood by people. It is actually a class of organic compounds that can absorb ultraviolet light and emit blue or blue-violet light.
In the national standard GB / T6687-2006 “Dye Terms ”, it is defined as follows: Fluorescent brightener is a colorless fluorescent dye that can excite blue and purple light under the irradiation of ultraviolet light. Yellow light is complementary and has a whitening effect. In simple terms, optical brighteners use optical color supplements to whiten, lighten or brighten white or light-colored items (such as textiles, plastics, paper, etc.). There is no chemical reaction between the items, but the optical effect is used to increase the whiteness of the object, and the fluorescence is used to increase the visual whiteness.
Therefore, fluorescent brighteners are also called optical brighteners, white fluorescent dyes. Fluorescent brighteners are substances that are intentionally manufactured by humans to generate fluorescence. Naturally, fluorescent substances are not included in this list. The purpose and use are not substances that generate fluorescence, and they are not fluorescent brighteners.
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