(PFE) using particles of size 0.3 μm is only measured in China. History Face masks for use in surgery were developed in Europe by several physicians, including Jan Mikulicz-Radecki at the University of Breslau and Paul Berger in Paris, in the late nineteenth century, as a result of increasing awareness of germ theory and the importance of antiseptic procedures in medicine. In response to a pneumonic plague in Manchuria and Mongolia in 1910, Chinese-Malaysian epidemiologist Dr. Wu Lien-teh greatly improved on the designs he had seen in Europe to develop a face mask of layers of gauze and cotton that would protect both the wearer and others. Modern surgical masks began to be used in the 1960s. Their adoption caused cloth facemasks, which had been used since the late 19th century, to completely fall out of use in the developed world. However, cloth masks and surgical masks both continued to be used in developing countries. COVID-19 pandemic As the pandemic raged on, healthcare workers were required to continue wearing surgical masks for 12 or more hours a day. This caused the ear loops of the masks to chafe the back of their ears. Ear savers, plastic straps and hooks that go around wearer's heads, were invented to move the ear loops away from the wearer's ears. They could be made on demand by using 3D printing process. Use Healthcare workers A surgical mask is intended to be worn by health professionals during surgery and certain health care procedures to catch microorganisms shed in liquid droplets and aerosols from the wearer's mouth and nose. Evidence supports the effectiveness of surgical masks in reducing the risk of infection among other healthcare workers and in the community. However, a Cochrane review found that there is no clear evidence that disposable face masks worn by members of the surgical team would reduce the risk of wound infections after clean surgical procedures. Healthcare workers are trained in how to put on, handle, remove, and dispose of surgical masks. For healthcare workers, safety guidelines recommend the wearing of a face-fit tested N95 or FFP3 respirator mask instead of a surgical mask in the vicinity of pandemic-flu patients, to reduce the exposure of the wearer to potentially infectious aerosols and airborne liquid droplets. General public In community and home settings, the use of facemasks and respirators generally are not recommended, with other measures preferred such as avoiding