N95 masks require hand hygiene before wearing them. The light color is on the inside and the metal strip is on the top. When wearing it, press the metal strip to make it fit your face.
Under normal circumstances, N95 masks are usually replaced every 4 hours. Because it takes too long, the mask loses its function. In some special circumstances, it cannot be worn for a long time. If the mask is damaged, contaminated, has a peculiar smell in the mask, or the mask no longer fits the face completely, it must be replaced in time under these circumstances.
N95 masks are not suitable for children under 7 years old. N95 masks have high breathing resistance after being worn and are not suitable for children under 7 years old. Therefore, parents should try their best to wear special or suitable masks for their children.
The development history of N95 masks:
The N95 mask is one of the nine types of particle protective masks certified by NIOSH. "N" means not resistant to oil. "95" means that when exposed to a specified number of special test particles, the particle concentration inside the mask is more than 95% lower than the particle concentration outside the mask.
In 1992, while teaching at the University of Tennessee, Chinese-American scientist Cai Bingyi led a team to develop a material with positive and negative charges that can absorb 95% of dust, bacteria, viruses and other microparticles. Make it polarize before passing through the mask.
This key material was soon used to make disposable N95 masks for personal use. In 1996, the U.S. Centers for Disease Control and Prevention (U.S. Centers for Disease Control) discovered that N95 masks can also absorb and block viruses. In 1995, the technology developed by Cai Bingyi obtained a U.S. patent.