How to determine whether the hotel has changed sheets and ultraviolet lights?

Fluorescent agent (also known as whitening agent, optical whitening agent, fluorescent whitening agent) detection, here provides a simple and low-cost method, which can be irradiated with a 365nm ultraviolet flashlight (or ultraviolet money detector). If there is blue-purple fluorescence (usually blue, purple, green and red, it is much brighter than the original color, so just take a few more photos of other items). This flashlight is sold on TB. Search (fluorescent agent detection) is not expensive, generally around 10-30 yuan, which is quite practical. Textiles, plastic products, skin care products, paper, etc. (Except some foods with special fluorescence reaction, such as rice fat) contains fluorescent agent. Pay attention to testing in the future, especially for babies, or personal products and skin care products. If it is a three-no product, there is indeed a risk of containing fluorescent agent. In daily life, there are many opportunities to contact fluorescent agents. As long as it does not exceed a certain standard (the above method can only detect whether it contains fluorescent agent, but not whether it exceeds the standard), it will bring many benefits to our lives. If you come into excessive contact with it, it will do harm to the human body. Tip: you can't see ultraviolet rays without irradiating fluorescent substances (if there is a small amount of white light, it is part of the visible light emitted by lamp beads, not ultraviolet rays). If it can be seen by reflection, it means that the irradiated object has a fluorescent reaction. Ultraviolet rays are harmful to human body. Avoid direct contact with human body and long-term use.