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 a face mask with disney characters, designed for children passengers on public transport in mexico city wearing face masks during the 2009 swine flu pandemic. in community and home settings, the use of facemasks and respirators generally are not recommended, with other measures preferred such as avoiding close contact, maintaining good hand hygiene, and wearing cloth face coverings. in japan and taiwan, surgical masks have commonly been worn in winter months during the flu season by those who have respiratory illnesses as a courtesy intended to prevent viral transmission. surgical masks provide some protection against the spread of diseases, and improvised masks provide about half as much protection. people in japan as well as korea and china may also wear masks in any season because of air pollution or allergies. some younger japanese people wear masks and audio headsets to signal a desire to avoid interaction. it has been suggested that mask-wearing as a custom appeared in east asia rather than other parts of the world also facing pollution and disease due to the historical influence of traditional chinese medicine and its ideas about air and wind. more recently, due to the rising issue of smog in south and southeast asia, surgical masks and air filtering face masks are now frequently used in major cities in india, nepal and thailand when air quality deteriorates to toxic levels. additionally, face masks are used in indonesia, malaysia and singapore during the southeast asian haze season. air filtering surgical-style masks are quite popular across asia and as a result, many companies have released masks that not only prevent the breathing in of airborne dust particles but are also fashionable. in japan, some use masks as fashion statements, at times as a result of influence from k-pop stars. surgical masks may also be worn to conceal identity. in the united states banks, convenience stores, etc. have banned their use as a result of criminals repeatedly doing so, but allowed facemasks due to the covid-19 pandemic. in the 2019–20 hong kong protests, some protestors wore surgical masks amongst other types of mask to avoid recognition, and the government tried to ban such use. research carried out during the covid-19 pandemic found that surgical masks increase the attractiveness of the wearer and this is more so than other types of masks. research and development researchers are developing face-masks which may help reduce viral spread better than existing ones and/or have possibly useful properties such as biodegradability or better breathability. some are exploring whether attachments could be added to existing face-masks to make them more effective such as due to virus-deactivating fabrics or impregnations. the covid-19 pandemic increased efforts to develop such masks. there also is an experimental face mask with an embedded biosensor that can detect a pathogenic signature (such as one of sars-cov-2) and face masks that glow under ultraviolet light if they contain sars-cov-2 when the filter is taken out and sprayed with a fluorescent dye that contains antibodies from ostrich eggs. other research investigated environmental pollution associated with face mask waste management and weak spots of masks with product designs of the widely applied ffp standards, in particular variants with exhalation valves. regulation single-use medical masks in the united states, surgical masks are cleared for marketing by the u.s. food and drug administration. in the european economic area (eea), surgical masks have to be certified through the ce marking process in order to be commercialized. ce marking of surgical masks involves the respect of many obligations indicated in the medical device regulation (council regulation 2017/745 of 5 april 2017 concerning medical devices, oj no l 117/1 of 2017-05-05). surgical masks for use in the us and the eea conform to astm f2100 and en 14683 respectively. in both standards, a mask must have a bacterial filtration efficiency (bfe) of more than 95%, for an aerosol of particles of size approximately 3.0 μm. in china, two types of masks are common: surgical masks that conform to yy 0469 standard (bfe ≥ 95%, pfe ≥ 30%, splash resistance) and single-use medical masks that conform to yy/t 0969 standard (bfe ≥ 95%). daily protective masks conforming to gb/t 32610 standard is yet another type of masks that can have similar appearance to surgical masks. sensorized surgical masks in 2014, firat güder while he was a research fellow at harvard university, together with professor george whitesides, invented a wireless surgical face mask that can monitor breathing of the individual wearing the mask. their technology relied on disposal paper-based printed sensors which could be integrated into the mask. the technology, which was first published in 2016, led to the formation of a start-up (spyras ltd) company to commercialize it which was later acquired.