On October 6th, 2024, Mr. Shi, the general manager of a company in Zhuhai, was on a business trip to Shenzhen. At the suggestion of an old friend, he bought a “八千八” brand negative ion air purifier and carried it with him. He started using it in the hotel. This small and portable negative ion air purifier is compact in size, and its purifying capacity isn't that strong, so there was no obvious effect after using it for just one hour. However, after running it for a whole night, when he went to his colleague's room, where there was no negative ion air purifier, the next morning and then returned to his own room, the difference was palpable. The room with the negative ion air purifier running overnight had basically no strange smell, while the other room still had a rather unpleasant odor.

After Mr. Shi returned, he bought another seven units and gave them to his colleagues who often go on business trips.