Patent Publication Number: US-2023147043-A1

Title: A face-gaiter source control mask

Description:
FIELD OF INVENTION 
     The present invention relates to a source control mask, in particular the invention relates to a face-gaiter-style source control mask. 
     BACKGROUND TO THE INVENTION 
     The air we exhale when we breathe contains a lot of water, some inert matter and can contain bacteria and virus. “Source control” prevents the transfer of pathogens from an infected person to a susceptible person/other people either directly through the inhalation of expelled aerosols or indirectly though transfer of material from droplets via contaminated surfaces. In relation to wearing face coverings/masks, source control is the containment of exhaled particles that pose a risk of infecting others. The bacteria and virus that pose this risk are carried in particles, i.e. droplets and aerosols, which are composed mainly of water. Droplets and aerosols are emitted at body temperature into an environment which is typically cooler, and this means the air we exhale and at least some of the particles in the air can become positively buoyant and tend to rise. 
     It is helpful to think of aerosols as particles that are light enough to be buoyant and droplets as particles that are too dense to become buoyant. Both sets of particles are carried by the air stream when exhaled during normal breathing at around 1 m/s. This air stream quickly disperses and slows down as it travels away from you i.e. the air stream takes around 3 s to travel the first metre and a further 9 s to travel the second metre. As the air flow slows down, droplets i.e. larger particles are affected by gravity and start to fall, and the droplets will settle on the surfaces they make contact with, for example table tops, floor etc. At the same time the air and aerosols i.e. smaller particles which are less dense than the surrounding air begin to deflect upwards towards the ceiling. The aerosols begin to interact with the environment, including other aerosols, losing heat and either losing or gaining mass depending on the conditions. Some of these aerosols may stay buoyant for hours and will disperse widely within any confined space until they are able to settle on a surface, potentially hours later. Some of the particles will be neutrally buoyant and these will continue in a straight line and it is likely that these will initially travel the farthest from the source (2-3 m) before losing momentum and are then carried by the air currents within the space. The buoyancy of these aerosols is not fixed but varies slowly over time with exchanges with the environment. 
     A high percentage of droplets i.e. larger particles greater than 50 um, can be contained by most types of face covering. The inertia of droplets means they will impact on and be contained by anything that is put in their way. Catching them in a face covering/mask stops them from being deposited on surfaces where other people may encounter them. The droplets themselves provide an environment that is more likely to sustain infectivity of the pathogens for the maximum length of time. Therefore, containment of droplets can reduce transmission of pathogens from the upper respiratory tract where these larger particles are generated when talking, singing, coughing and sneezing. 
     Aerosols i.e. buoyant particles are generated in both the lower and upper respiratory tract. Aerosols below 10 μm can be inhaled directly into the lungs of another person. Aerosols are more difficult to contain than droplets, the buoyancy of aerosols mean they are carried by the air stream through the fabric of the face covering/mask when the fabric composition includes voids that cannot prevent egress or through small gaps around the perimeter of the face covering/mask. It will be appreciated, aerosols can potentially pass through any void or gap which permits the passage of air and is larger than the aerosol. 
     Regarding containment of aerosols and droplets i.e. small and large particles, gaps/spaces around the perimeter of a face covering/mask play a dominant role in the performance of a face covering/mask. It will be appreciated, air, as a fluid, follows the path of least resistance, therefore a large percentage of the air exhaled will pass through even a small gap at the perimeter of the face covering/mask when there is a high resistance to the passage of air, through the fabric of the face covering/mask. 
     Typically, in hospitals and medical establishments, source control is managed by the use of disposable surgical masks. Such masks were designed to protect patients against possible infection transmitted from a surgeon and their medical team. 
     Disposable masks are inexpensive, readily available and are configured to be one-size fits all i.e. they fit all face types in a similar way. 
     The fabric composition of a disposable surgical mask is often able to filter more than 95% of exhaled aerosols, which are larger than 0.3 μm. It will be appreciated, that such a fabric composition will resist the passage of air through the body of the fabric. Therefore, as the user breathes normally each exhalation will produce an output of aerosols and droplets, the passage of which will be resisted by the fabric composition. However, as noted above the flow path of exhaled air, which contains aerosols and droplets, will be the path of least resistance. Therefore, any gap or void at the perimeter will provide an exit route/path for the exhaled matter. For example: for a surgical mask, a gap of approximately 12 mm 2  has been shown to permit 50% of aerosols to escape from behind the face covering/mask while a visible gap will permit almost all aerosols to escape from behind a face covering/mask. 
     At normal breathing rates for example when walking, talking or even singing, the pressure of exhaled air behind a surgical mask is around 50 to 100 Pa (Pa=Pascal) i.e. the pressure required to force exhaled air through the fabric, this resistance to the air passing through the fabric means that even a very small gap will allow at least some of the air and the aerosols carried by it to escape from behind the face covering/mask via the gap. Even if the disposable face covering/mask is fitted with no visible gaps, and the user avoids talking and adjusting the fit, which may create a gap or gaps, the peak pressure generated by exhalation alone is capable of displacing the face covering/mask. This resulting displacement will create a gap about the perimeter of the face covering/mask and the gap will therefore facilitate the escape of air and the associated aerosols to exit from behind the face covering/mask. It will be appreciated that exertion will increase the breathing rate and therefore increase the pressure, making it more likely that exhalation could displace the mask and create additional unwanted gaps about the perimeter of the face covering/mask. 
     Face covering/masks can also be used to protect a person wearing the mask from inhalation of airborne matter, for example dust particles, pollution particles, pathogenic bacteria, pathogenic viruses, etc. The ability to protect the user from inhaling such matter typically depends on the filtration capability of the mask. Conventional masks are considered particularly useful to prevent inhalation of airborne bacteria and viruses, for example cold and flu viruses. 
     The year 2020 experienced a worldwide outbreak of a virus, SARS-Co-V2, resulting in a global pandemic. The pandemic saw many people dismiss the danger of the virus, but also saw many people wear masks of various shapes and forms in an attempt to prevent spread of infection. 
     The pandemic caused government leaders throughout the world to enforce lockdowns, meaning movement of the world population was restricted, physical contact with others was restricted and social distancing measures were put in place. All such measures were put in place to limit/restrict transfer of the virus, which in many cases caused death of the infected person. 
     During the time of the global pandemic and particularly on occasions when people were unavoidably in contact with others, for example whilst working and being involved in other essential tasks, e.g. shopping etc, it became compulsory, unless exempted, that masks be worn. Much of the population opted for surgical-type masks or masks made to a similar pattern/design. 
     Surgical-type masks are those that include a pleated front section and two ear loops and are worn across the mouth and nose. Surgical-type masks are typically loose fitting, typically do not provide the user with a reliable seal around the mouth and nose because leakage occurs around the edge of the mask as the user inhales and typically they do not provide the user with a reliable level of protection from inhaling small airborne particles. Surgical-type masks are not designed to provide any respiratory protection. 
     To the lay person surgical masks would be expected to provide a high-level of protection to the user due to the description and the typical application of such masks. This is apparent by the number of people making fabric masks to the same design as a surgical mask. 
     SUMMARY OF THE INVENTION 
     The present invention provides a face-gaiter mask comprising a tubular construction of fabric, which is configured, in use, for an upper front centre of the tubular construction to rest on an upper part of the user&#39;s nose, and for the tubular construction to extend down and drape over the user&#39;s nose, the user&#39;s mouth and the user&#39;s neck; wherein the face-gaiter mask comprises a top seal, a front filter section, a rear section and a neck seal, wherein, in use the front filter section is located to the front of the user&#39;s face and is configured to cover at least the user&#39;s nostrils and the user&#39;s mouth; 
     wherein the front filter section includes at least two fabric layers, wherein the at least two fabric layers are configured to provide a predetermined level of filtration and resistance to airflow through the filter section; 
     wherein the top seal comprises a nose detail, wherein the nose detail extends from an upper edge of the front filter section and extends at least partway into the front filter section, wherein the nose detail defines a localised stiffener to an upper edge and upper circumference of the face-gaiter mask and facilitates correct alignment of the front filter section of the face-gaiter mask in use, wherein, in use the nose detail rests upon and aligns with the user&#39;s nasal bone; 
     wherein the neck seal comprises draping fabric, which extends from the front filter section and in use drapes across the user&#39;s neck area and creates a seal about the user&#39;s shoulder and upper chest area; and 
     wherein fabric forming the face-gaiter mask between the top seal and a lower edge of the neck seal is configured to drape loosely in random folds, which in use provide a fluid configuration and fluid surface area upon which exhaled aerosols and particles can be trapped. 
     The configuration of the face-gaiter mask is configured such that there are no gaps, there is low resistance to airflow and to provide filtration at a predetermined level. These features mean the face-gaiter mask can protect the user and people in close proximity to the user from the air exhaled by the user and from the air inhaled from the environment in which the mask is worn. 
     The nose-detail may be a kite-shaped detail extending down from the upper edge of the filter section, wherein upper and lower vertices and vertical diagonal of the nose-detail are configured, such that in use they align with the user&#39;s nasal bone. The nose-detail may be a visible feature on the exterior of the face-gaiter mask. Alternatively, the nose-detail may be concealed from exterior view, but may be visible from the interior of the face-gaiter mask. 
     The nose-detail facilitates sealing between the user&#39;s face and the upper edge of the face-gaiter mask and also facilitates proper alignment of the face-gaiter mask on a user&#39;s face. 
     The top seal may further comprise a nose seal proximate the upper edge of the filter section, wherein the nose seal is arranged, in use, to create a seal between the upper edge of the front section, across the user&#39;s nose and alongside the user&#39;s nose. The nose seal may comprise one or more deformable members, which is/are attached proximate to an upper edge of the filter section substantially symmetrically relative to the nose-detail. 
     The nose seal may include two wedged inserts, where one insert is attached to each side of the nose-detail. Alternatively, the nose seal may comprise a single contoured insert, wherein the contours of the insert are configured to correspond substantially with contours of a user&#39;s nose and cheek area. 
     The nose seal may be manufactured from deformable foam. 
     For optimum comfort and to ensure an optimum seal, the nose seal may be made to suit the nose profile of a specific user e.g. by scanning the user&#39;s face and using additive manufacturing (rapid manufacturing) to make a single customised nose seal such that the contoured insert conforms to the shape of the user&#39;s nose to cheek area. 
     The contoured nose seal may include a recessed section, which is shaped such that the nose seal rests on the bridge of the user&#39;s and two convex sections, which are shaped to bridge a gap between the upper edge of the face-gaiter and the user&#39;s nose and cheek area. 
     The shape and configuration of the upper edge of the face-gaiter mask, including the nose-detail and nose seal is such that gaps are substantially eliminated. As such the face-gaiter mask is suitable for all face shapes and head sizes and avoids gaps created by facial hair because the face-gaiter seals away from the hairline. 
     Low resistance to air flow reduces the effort required to breathe when wearing the face-gaiter mask and reduces the pressure created within the mask when the user inhales and exhales (breathes in and out). Reducing the pressure when the user inhales prevents the fabric of the mask being drawn against the user&#39;s mouth. This is particularly important during exertion (for example when exercising), which causes the user to breathe harder. Reducing the pressure when the user exhales allows easier air exchange reducing the temperature and CO 2  levels within the mask. It also reduces the pressure on the nose seal, the top seal and the neck seal ensuring the seal is not prone to leakage or failure. 
     The filter section may include an additional filter layer, wherein the filter layer occupies at least an upper portion of the filter section. The filter layer may be attached to an inner layer of the at least two layers. Alternatively, the filter layer may be sandwiched between two of the at least two layers. 
     The filter layer may include a bulbous body and two upper pockets, wherein the pockets are configured to retain the nose seal relative to the nose-detail. 
     The filter layer may extend substantially the full width and length of the filter section of the face-gaiter. 
     The filter layer may be made from one or more layers of fabric, wherein the fabric comprises multiple or blended yarns. 
     The filter layer may be configured to catch aerosols smaller than 10 μm. 
     The filter layer may be configured to catch aerosols smaller than 3 μm. 
     The filter layer may be made from non-woven fabrics, fleece type knitted fabrics or tight knitted fleece fabrics. Fleece type warp knitted fabrics are very durable. 
     The filter layer may be made from polyester, nylon or cellulose based yarns; fine gauge tight knitted wools; non-woven fabrics made of very fine yarns such as cellulose, split polyester, split nylon and melt blown polypropylene. 
     The at least two layers may be made integrally of the same fabric, wherein the layers are created by folding fabric. Alternatively, each layer of the least two layers may be different materials. 
     The filter section of the face-gaiter mask may include an inner layer, an outer layer and a filter layer sandwiched between the inner layer and the outer layer. 
     The inner layer may be made from hygroscopic fabric. A hygroscopic fabric aids filtration by having an affinity to the moisture in the particles a user exhales. The inner layer may therefore be configured to capture larger droplets and some aerosols and reduce the absorption demand on the filter layer, where the filter layer is sandwiched between the inner layer and the outer layer. 
     The outer layer is operable to protect the filter layer. The outer layer may be more porous than the filter layer and more porous than the inner layer such that any pathogen from the environment that is filtered by the face-gaiter mask is likely to pass through the outer layer and be held on the outer surface of the filter layer. The outer layer acts as a barrier to reduce the likelihood of the user transferring any pathogens to their hands or other surfaces when lifting, lowering or removing the mask. 
     The outer layer may be made of a warp knit polyester. A warp knit polyester is very durable and can be printed with designs or dyed such that the face-gaiter can be coordinated and aesthetically pleasing for the user, whilst being functionally efficient. 
     The rear portion, may be joined along edges of the filter section to form the fabric tube. 
     The rear portion may be made a flexible and pliable material, which ensures the face-gaiter mask can be pulled over a user&#39;s head. The rear portion may include a resilient rear upper edge, which ensures the rear upper edge of the rear portion fits snuggly against the user&#39;s head when the face-gaiter mask is worn. 
     The upper edge may include an elasticated section, wherein a length of elastic is secured to the upper edge such that, in use, the upper edge of the rear portion fits snuggly against the user&#39;s head. 
     The rear portion may be made of the same material as the outer layer. 
     Resilience of the rear upper edge, including elastic or not including elastic is such that when the mask is worn the configuration of the circumferential upper edge i.e. front upper edge and the rear upper edge of the face-gaiter mask is such that the upper circumference of the face-gaiter mask is sealed against the user&#39;s face and head to prevent airflow from the upper edge of the face-gaiter mask. 
     The rear upper edge, elasticated or not, is configured to apply consistent tension around the top of the mask. Consistent/constant tension facilitates the creation of a top seal and, upon rotation of the user&#39;s head, prevents the top seal being broken or dislodged and prevents leakage/airflow through the seal. 
     At least the upper edge of the rear portion may be configured to stretch by at least 50%. This is such that the mask can be comfortably pulled over the user&#39;s head and such that the top seal is created and such that no leakage occurs via the top seal. 
     The rear portion may be made of impermeable fabric. Alternatively, the rear portion may be made of a layered construction such that the rear portion is impermeable. The layered construction may include at least two flexible/pliable materials, wherein at least one material is non-porous. The rear portion may include a layer of polyurethane, natural rubber or synthetic rubber. 
     The neck seal may include a tapered lower edge, wherein, in use, the lower edge rests against the user&#39;s upper torso or clothing such that a seal is created. 
     The tapered lower edge increases surface contact between the face-gaiter mask and the user compared with a mask having a straight/horizontal lower edge. Therefore, the tapered lower edge improves the neck seal. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       An embodiment of the present invention will now be described with reference to the accompanying drawings in which: 
         FIG.  1 A  illustrates a side view of a first example of a face-gaiter mask being worn; 
         FIG.  1 B  illustrates of a front view of the face-gaiter mask shown in  FIG.  1 A ; 
         FIG.  2 A  illustrates a fabric insert blank/template of a filter layer; 
         FIG.  2 B  illustrates the fabric insert of  FIG.  2 A  and an example of a stitching configuration used to secure the filter layer to the upper portion of the face-gaiter illustrated in  FIGS.  1 A and  1 B ; 
         FIG.  2 C  illustrates a nose-seal for inclusion with the fabric insert of  FIGS.  2 A and  2 B ; 
         FIG.  3 A  illustrates an external view of the face-gaiter of  FIGS.  1 A and  1 B  including the stitched filter layer; and 
         FIG.  3 B  illustrates an interior view of the front section of the face-gaiter of  FIGS.  1 A and  1 B  showing the arrangement of the filter layer and a nose seal. 
         FIGS.  4 A and  4 B  illustrate a side view of a second example of a face-gaiter mask being worn; 
         FIG.  4 C  illustrates of a front view of the face-gaiter mask shown in  FIGS.  4 A and  4 B ; 
         FIG.  4 D  illustrates an exploded view of front and rear panels of face-gaiter mask of  FIGS.  4 A,  4 B and  4 C ; 
         FIG.  5    illustrates an example of a first nose seal configuration; 
         FIG.  6 A to  6 D  illustrate an example of a second nose seal configuration; and 
         FIG.  7 A to  7 D  illustrate an example of a third nose seal configuration. 
     
    
    
     DESCRIPTION 
     A first example of a face-gaiter mask  10  (a virus control/source control mask) is illustrated in  FIGS.  1 A  and,  1 B. The face-gaiter mask/face-gaiter  10  is configured to reduce the spread of virus and bacteria from the user to the user&#39;s environment. Therefore, the face-gaiter  10 , when worn as illustrated in  FIGS.  1 A and  1 B  is configured to protect, not only the user, but other people, who are in close proximity of the user, from air expelled by the user e.g. during breathing, speaking, coughing, sneezing etc. 
     The face-gaiter  10  performs as source control i.e. if every person within a group in a given location or in close proximity wears a face-gaiter  10  the entire group is protected. In one example, if one person in a group is infected with a virus and that person is the only person in the group wearing a face-gaiter  10  the configuration of the face-gaiter  10  is such that transmittal of the virus from the user is reduced. 
     The face-gaiter  10  includes an upper portion  10 A and lower portion  10 B. In the illustrated example, the upper portion  10 A is made of at least two layers of material and is fabricated to include a nose detail  12 . The nose detail  12  facilitates proper alignment of the face-gaiter  10  on the user&#39;s face and reduces the upper perimeter  14  i.e. the perimeter at the top of the face-gaiter  10  to ensure a secure fit to the profile of the user&#39;s face in the region adjacent to and across the bridge of the nose and under the user&#39;s eyes. The nose detail  12  is stitched in the form of a diamond/kite-shape and facilitates tight fitting about the nose, but loose fitting around the nostril and mouth area. 
     The stitched nose detail  12  creates stiffness in the appropriate area whilst helping to keep the fabric off the user&#39;s face. This can be further enhanced by inserting a stiffer material inside this section before it is stitched. 
     The space created in front of the user&#39;s mouth allows all discharge to spread out and this reduces the air pressure driving/forcing these particles to penetrate the fabric in front of the user&#39;s mouth. 
     The looseness of the fabric in front of the user&#39;s mouth and the multiple layers i.e. at least double layer thickness of the fabric in this area (at least in the front section located in front of the user&#39;s mouth and nostrils restricts air flow in the upper portion  10 A more than the more breathable fabric at the lower portion  10 B such that air flow between the inside and outside of the face-gaiter  10  occurs within a very much larger area compared with the area in conventional masks. This configuration reduces the air pressure between the inside and outside of the face-gaiter  10  further and spreads any contamination expelled by the user over a much larger area so that any particles and aerosols are easier to contain within the volume created between the face-gaiter  10  and the user&#39;s face. 
     In the illustrated example, the face-gaiter  10  is made from fabric that is flexible, pliable/stretchy in the circumferential direction i.e. in the direction that wraps the face-gaiter  10  around the user&#39;s face. A hemmed section or reinforced upper perimeter  14  i.e. proximate the top of the face-gaiter  10  increases the force holding the face-gaiter  10  in place i.e. against the user&#39;s face. The hemmed section or reinforced perimeter can be narrow i.e. proximate the upper edge of the face-gaiter  10  or the hemmed section or reinforced perimeter can extend further down i.e. towards the user&#39;s chin whilst maintaining space/volume in front of the user&#39;s mouth. 
     Using a flexible/pliable/stretchy fabric helps/ensures the face-gaiter  10  has a top seal i.e. fits snuggly around the user&#39;s face in the area under the eyes, over the bridge of the nose and around the head. 
     The fit of the face-gaiter around the user&#39;s nose is improved by the stitched nose detail  12  i.e. the diamond/kite-shaped feature. 
     The lower portion  10 B i.e. the bottom of the face-gaiter  10  is configured to extend down and rest loosely on the user&#39;s shoulders, upper chest and about the user&#39;s neck. This arrangement creates a neck seal between the fabric of the lower portion  10 B of the face-gaiter  10  and the user&#39;s clothing. The lower portion  10 B is configured to have higher permeability that the upper portion  10 A to encourage the exhaled air to flow down across the face and through as much of the volume created within the face-gaiter  10  as possible. This configuration utilises the maximum area of fabric possible in order to minimise the pressure difference between the inside and outside of the face-gaiter  10  and to maximise the area of fabric available to filter the air. 
     In the illustrated example ( FIG.  1 A  and  FIG.  1 B ), the face-gaiter  10  is made in the form of a tube/sleeve of fabric which is formed from a sheet of fabric folded about its centre line and the two outer edges are stitched together to form the tube. Alternatively, the tube could be formed from a woven or knitted tube/sleeve of material (not illustrated) or two or more panels joined/stitched together. 
     In the illustrated example, the lower front-edge  17  of the face-gaiter  10  tapers downward such that the when worn the lower edge forms a bottom/neck seal between the face-gaiter  10  and the user. Additionally, the elongated tubular configuration of the face-gaiter  10  is such that the fabric below the nose and mouth region hangs/drapes and creates waterfall folds in the body of the fabric, in particular, about the user&#39;s neck and upper chest. 
     The face-gaiter  10  can be made to a size to suit the user&#39;s head circumference in the region of the user&#39;s nose i.e. the circumference around the user&#39;s head and across the bridge of the user&#39;s nose. Proper sizing improves the sealing fit of the face-gaiter  10  against the user&#39;s face and head. 
     Proper sizing also ensures a bottom seal/neck seal, defined by the interaction of the lower edge  23  of the face-gaiter  10  and the user&#39;s skin or clothing. The length and looseness of the fabric creating the lower portion  10 B ensures the bottom seal/neck seal is maintained even when the user bends his/her head backwards i.e. when looking upwards. 
     The lower portion  10 B, lower edge  23  and the tapered front edge  17  create a neck seal against the user&#39;s skin or clothes. The draped nature of the lower portion  10 B allows for movement and displacement of the fabric whilst not disturbing the neck seal i.e. not moving the lower edges  23 ,  17 , thus maintaining a seal between the lower edges  23 ,  17  of the face-gaiter  10  and the user&#39;s skin or clothing. 
     In the illustrated example, the upper portion  10 A includes at least two fabric layers, which is produced by folding inwards and downwards an upper edge of the tube and stitching the edge to the body of the fabric to produce a circumferential seam  19  approximately one-third down from the created upper circumference  14 . 
     In the illustrated example, the nose-detail  12  is created by first folding the front panel of the upper portion  10 A in half about the lengthwise centreline. An angled seam line is then stitched to form a stitched triangle, defined between the long edge and the upper circumference edge  14 . The panel  10 A is then rearranged flat such that the stitched triangle is located top, front and centre. The stitched triangular seam is pressed flat against the body of the fabric to create a kite-shaped nose detail  12 . The kite-shape is stitched in place to define a localised stiffened region i.e. the nose detail  12 . 
     In the illustrated example, the kite-shaped nose detail  12  is visible on the exterior of the front panel/portion  10 A of the face-gaiter  10 ,  100 . The shape of the nose detail  12  is such that, in use, the upper and lower vertices  32 ,  34  and the vertical diagonal  36  rest upon and align with the centreline of the user&#39;s nose (see  FIG.  1 B ). It will be appreciated that the nose detail  12  facilitates proper alignment of the face-gaiter  10  on the user&#39;s face. 
     The physical manufacture of the nose detail  12  reduces the perimeter/circumference of the upper circumference  14  of the face-gaiter  10  such that a secure/snug fit for the user is assured where the upper circumference  14  is in contact with the user&#39;s face and head. 
     The fabric extending down from the upper circumference  14  and the nose detail  12  is loose such that the volume defined below the upper circumference  14  and in front of the user&#39;s nose and mouth is generous and the fabric drapes into waterfall folds such that the body of the fabric in the lower portion  10 B flows and is loose fitting about the nostrils and mouth area. It will be appreciated; the act of breathing may cause the fabric to move towards the user on inhalation and away from the user on exhalation. However, the configuration of the face-gaiter  10  is such that inhalation and exhalation will have little or no effect on the position of the fabric relative to the user&#39;s face because the looseness of fabric and the volume created below the nostrils and in front of the user&#39;s mouth is such that air pressure directly in front of the mouth is reduced because air flow is encouraged downwards into the area between the user&#39;s neck and the fabric of the face-gaiter  10 . 
     The volume between the user&#39;s neck and the fabric is where the face-gaiter  10  is loosest, as such air flow is decelerated as it passes over the folds of fabric into the larger volume. The illustrated configuration improves containment of air flow within the volume defined by the face-gaiter  10  and the user&#39;s face, neck and upper chest. 
     The illustrated face-gaiter  10  is configured to prevent the mask fabric being drawn against the user&#39;s mouth when inhaling hard, which could restrict air flow and be uncomfortable for the user. 
     The upper circumference  14  of the face-gaiter  10  is sized to ensure a secure and sealing fit of the upper circumference (top seal)  14  against the user&#39;s face in the region across the bridge of the nose (nasion bone), adjacent to the bridge of the nose and the cheek bone (zygomatic bone) area i.e. the area under the user&#39;s eyes. 
     The nose detail  12  creates stiffness in the appropriate area whilst helping to keep the mask fabric off the face in the nostril and mouth area. It will be appreciated that the stiffness of the upper circumference  14  can be further enhanced by inserting, a stiffer material inside the fold whilst creating the upper circumference  14 . 
     The fit of the face-gaiter  10  and the filtration capacity of the face-gaiter  10  can be enhanced by the addition of a filter insert  80  and/or a nose seal  60  (see  FIGS.  2 A,  2 B and  2 C ). 
     The filter insert  80  is provided by a fleece-type fabric, which is added to the upper portion  10 A and is configured to extend across each side of the user&#39;s nose and to extend down in front of the mouth i.e. is located in front of the user&#39;s mouth. This arrangement increases the resistance to air flow in front of the user&#39;s mouth where air flow is greatest. The addition of the filter  80  can also act to retain particles expelled from the user&#39;s mouth. 
     The addition of a shaped fabric piece, for example the filter insert  80  increases resistance to air expelled from the user&#39;s mouth and significantly improves sealing between the face-gaiter  10  and the sides of the user&#39;s nose. This improved seal reduces the amount of air entering the face-gaiter  10  directly i.e. not through the fabric of the face-gaiter  10  and thereby significantly increases the protection offered to the user. 
     In the illustrated example, the filter insert  80  i.e. a fabric piece is added inside the face-gaiter  10  in the area in front of the user&#39;s mouth. 
     The filter insert  80  includes a pair of tabs  82  (see  FIG.  2 A ), which are rolled into a deformable hollow tube  83  (see  FIG.  2 B ) that can conform to the contours of the user&#39;s face and the sides of the user&#39;s nose when the force from the upper circumference presses on the hollow tubes  83 . This arrangement creates an airtight seal i.e. no gaps in the area formed between the side of the user&#39;s nose, cheeks and the upper circumference  14  of the face-gaiter  10 . The hollow tubes  83  can be parallel as illustrated or tapered e.g. the tube is widest next to the user&#39;s nose. 
     In the illustrated example, the filter insert  80  also includes a V-shape cut out  86  that corresponds with the lower triangular portion of the kite-shaped nose-detail  12  and a bulbous lower portion  88 , which, in use, covers the area in front of the user&#39;s nose and the user&#39;s mouth. 
       FIGS.  3 A and  3 B  illustrate the filter insert  80  stitched  90  to the upper portion  10 A of the face-gaiter  10 .  FIG.  3 B  illustrates the filter insert with a nose seal  60  (see  FIG.  2 C ), which, is captured in the hollow tubes  83  created by rolling/folding the tabs  82 . 
     When the filter insert  80  (see  FIG.  3 B ) is secured to the upper portion  10 A of the face-gaiter  10  an upper edge  84  of the filter insert  80  aligns with the upper edge/upper circumference  14  of the face-gaiter  10  such that the nose seal  60  is positioned across and on each side of the user&#39;s nose to ensure that a seal i.e. no gap is provided between the upper circumference  14  of the face-gaiter  10  and the user&#39;s face and nose i.e. the nose seal  60  fills the triangular voids created between the upper circumference  14  of the face-gaiter  10 , the side of the user&#39;s nose and the user&#39;s cheeks. 
     The stitching  90  can be simple i.e. around the perimeter of the filter insert  80  to secure it simply to the upper portion  10 A of the face-gaiter  10  or it can be decorative, as illustrated in  FIG.  2 B ,  FIGS.  3 A and  3 B . 
     In the illustrated example, the filter insert  80  is made from a fleece-type fabric e.g. polyester or other suitable synthetics, but it will be appreciated the filter insert  80  could be made from other fabrics or a soft foam. 
     In the illustrated example, the filter insert  80  creates the inner surface of the face-gaiter  10  because it is attached to the inside of the face-gaiter  10 . However, it should be appreciated that the filter insert  80  could be sandwiched between the two layers providing the upper portion  10 A of the face-gaiter  10 . A channel i.e. hollow tube could be created on the inner face of the face-gaiter  10  to house the nose-seal  60  such that sealing between the upper circumference of the face-gaiter  10  and the user&#39;s face is optimised. 
     In another example (not illustrated) the filter insert could be made much larger and be utilised to keep the face-gaiter  10  off the user&#39;s face when the user is lying down e.g. lying in bed. In such an example, the filter insert could be made from an open lattice frame of soft foam, which would allow the volume in front of the user&#39;s mouth to be increased to further aid breathing i.e. the configuration of the filter insert creates a tent-like structure over the user&#39;s mouth and nose to prevent the fabric in front of the user&#39;s mouth restricting the user&#39;s breathing. 
     The lattice construction could be pliable so that it is not damaged if the user where to turn over and press on it or could be ridged and hard so that it could support such force without collapsing. 
     A second example of a face-gaiter  100  incorporating the nose detail  12  is illustrated in  FIGS.  4 A,  4 B,  4 C and  4 D . The face-gaiter  100  includes a front filter  100 A, a top seal  100 B, a neck seal/skirt  100 C and a rear portion  100 D. 
     In the illustrated example (see  FIG.  4 D  for clarity) the front filter  100 A is the entire front area of the face-gaiter  100  i.e. the front filter  100 A is the portion/section of the face-gaiter  100  that covers the user&#39;s nose, the user&#39;s mouth and drapes down over the user&#39;s neck and upper chest area. The front filter  100 A extends from the upper circumference  114  (including the top seal  100 B and nose seal  160 ) to the neck seal  100 C; the junction between the front filter  100 A and the neck seal  100 C is indicated by the thick line  119 . 
     The top seal  100 B, similar to the example illustrated in  FIGS.  3 A and  3 B  includes a nose seal  160  (shown dotted in  FIG.  4 C ), which ensures a seal i.e. no gaps between the upper circumference  114  of the face-gaiter  100  and the user&#39;s nose and face i.e. the user&#39;s cheeks. 
     The neck seal  100 C extends from the front filter  100 A to a lower tapered edge  123 ,  117  (bottom seal). 
     The circumferential extent of the front filter  100 A coincides with the circumferential extent of the rear portion  100 D where the front filter  100 A and rear portion  100 D create a complete tube, which forms the shape of the face-gaiter  100 . 
     In the illustrated example (see  FIG.  4 D ), the front filter  100 A includes an inner layer  120 , a filter layer  120 A and an outer layer  120 B. The dotted line  119  indicates the extent of the filter layer  120 A and the top of the neck seal  100 C. 
     Source control i.e. the filtration capability of the face-gaiter  100  is enhanced/improved by the filter layer  120 A extending over the entire front section of the face-gaiter  100  and covering the user&#39;s nose, mouth and neck. 
     The front filter  100 A extends from the upper circumference  114  and top seal  100 B and drapes down over the user&#39;s mouth, neck and upper chest area (see  FIGS.  4 A,  4 B and  4 C ) i.e. the front filter  100 A covers the area/zone into which the user breathes directly. The area of the front filter  100 A of the face-gaiter  100  is around six times greater than that provided by a traditional mask. 
     In the example illustrated, the front filter  100 A is made up of at least three layers of fabric (see  FIG.  4 D ). Each layer is configured to perform multiple functions and each layer itself may be constructed from multiple layers of fabric. The optimum fabric construction of the front filter  100 A is to provide adequate filtration with minimal resistance to airflow. 
     The inner layer  120  can be made from a hygroscopic fabric. A hygroscopic fabric aids filtration by having an affinity to the moisture in the particles a user exhales. The inner layer  120  is therefore configured to capture larger droplets and some aerosols and reduce the absorption demand on the filter layer, which is sandwiched between the inner layer and the outer layer. 
     The inner layer fabric  120  may also be configured to wick away moisture, such that the inner layer does not become saturated and feels dry where it touches the skin. Nylon, in particular, tight knitted nylon is an example of a fabric that attracts moisture but gives it up easily i.e. wicks moisture. Rayon, viscose and other cellulose based yarns are also suitable. These materials are generally better than cotton which attracts water but does not readily give it up and generally better than polyester which wicks well but only has a low capacity to attract moisture initially. 
     In the illustrated configuration i.e. the filter layer being sandwiched between the outer layer  1208  and the inner layer  120  a further purpose of the inner layer is to protect the filter layer  120 A. 
     The filter layer  120 A is designed to catch most of the aerosols below a specified size e.g. 10 μm. Examples of effective materials for the filter layer  120 A are non-woven fabrics, fleece type knitted fabrics (fleece type knitted fabrics are very durable) or tight knitted fleece fabrics. These are examples of a fabric constructed from multiple tangled fibres. Suitable materials (a non-exhaustive list) are polyester, nylon or cellulose based yarns; fine gauge tight knitted wools; non-woven fabrics made of very fine yarns such as cellulose, split polyester, split nylon and melt blown polypropylene. 
     Fleece type knitted fabrics are made by knitting the fabric with long loops. The loops are then cut or combed (broken). The resulting single fibres are firmly connected to a base fabric, but the single fibres are loose, such that they become tangled in a random way. The most effective fleece fabric for the filter layer  120 A is a fabric, which contains many fibres and the resulting dense fabric shows no pin holes when back lit with a strong light. This type of fabric enhances filtration of small aerosols below 3 um and may have a durable electrostatic charge that is not discharged by washing or be capable of being given an electrostatic charge after washing by, for example, tumble drying. This requires at least two of the layers to be as far apart as possible on the triboelectric series (wool, nylon and cotton being at the positive end and polypropylene and polyethylene being at the negative end). 
     The filter layer  120 A can be made from one or more layers of fabric made from single, multiple or blended yarns, but regardless of the number of layers the configuration of the filter layer is to optimise filtration at the highest possible porosity. Therefore, it will be appreciated that if the construction of layers reduces porosity of the filter (porosity being the ability of a fluid to flow through the fabric) a multiple layer filter will be counterproductive and will reduce the overall efficiency of the mask, unless the extremities of the face-gaiter  10  are efficiently sealed to the users face, head and body. 
     The filter layer  120 A is sandwiched between the inner layer  120  and outer layer  120 B. The inner and outer layers  120 ,  120 B may be more robust fabrics than the filter layer fabric  120 A such that the filter layer  120 A is protected and the inner and outer layers  120 ,  1208  increase protection of the user and persons proximate to the user. 
     In the illustrated example, the inner layer  120 , the filter layer  120 A and the outer layer  120 B are held together by stitching/seams. However, it will be appreciated that, bonding, welding or other mechanical means can be used to secure the filter layer  120 A to the inner and/or outer layers  120 ,  120 B. 
     As described above the filter layer  120 A is sandwiched between the inner and outer layers. Arranging the layers in this way, using dissimilar fabrics for each layer enhances the generation of a static charge; the static charge can significantly increase the filtration of small aerosols. 
     The filter layer  120 A and the fabrics it is constructed from must be durable and be able to withstand multiple washes so that it can be sterilised between uses and without losing filtration performance. The filter layer  120 A needs to generate the lowest possible back pressure to reduce the risk of leakage and the volume of leakage if this does occur. 
     The exposed outer layer  120 B i.e. the exterior surface of the face-gaiter  100  protects the filter layer  120 A. The outer layer  120 B is configured to be more porous than the filter layer  120 A and the inner layer  120  such that pathogens that are filtered by the face-gaiter  100 , from the user&#39;s environment, are likely to pass through the outer layer  1208  and be held on the outer surface of the filter layer  120 A. It will be appreciated, the outer layer  1208  acts as a barrier, which reduces the risk of the user transferring the pathogen to their hands or other surfaces when lifting, lowering or removing the face-gaiter  100 . 
     The outer layer  1208 , as noted above, defines the outer surface of the face-gaiter  100  i.e. the outer surface is the exterior surface that is visible to other people in the user&#39;s environment. As such the outer layer  120 B can be patterned, printed or dyed to make it aesthetically pleasing, fashionable etc. The aesthetic appeal e.g. to accessorise or coordinate with an outfit may encourage a user to wear the face-gaiter  100  more often than they would wear/use a conventional surgical type mask. 
     The inner layer  120  and the outer layer  120 B, each include an upper portion  130  and the lower portion  134 . The lower portion  134  corresponds with the neck seal  100 C. 
     Referring to  FIGS.  4 A,  4 B and  4 C , the fabric of the front filter  100 A is tight in the region of the top seal  100 B and the body of the fabric drapes loosely from the top seal  100 B creating waterfall-type folds, which create space beneath the user&#39;s nose in front of the user&#39;s mouth and neck area. This space allows all exhaled discharge from the user&#39;s nostrils or mouth to spread out within the face-gaiter  100  and therefore reduces the air pressure required to drive/force any discharged particles to penetrate the fabric in front of the mouth. A reduction in air pressure, the configuration of the at least three-layer thickness of the front filter  100 A and the draped/water fall portion of the face-gaiter  100  reduces the occurrence of penetration of any exhaled particles through the fabric and keeps the majority of any exhaled particles within the confines of the face-gaiter  100 . 
     In the illustrated example, the nose-detail  12  is created by first folding the front filter  100 A in half about the lengthwise centreline. An angled seamline is then stitched to form a stitched triangle, defined between the long edge and the upper circumference edge  114 . The panel  100 A is then rearranged flat such that the stitched triangle is located top, front and centre. The stitched triangular seam is pressed flat against the body of the fabric to create a kite-shaped nose detail  12 . The kite-shape is stitched in place to define a localised stiffened region i.e. the nose detail  12 . 
     In the illustrated example, the kite-shaped nose detail  12  is visible on the exterior of the front panel/portion  100 A of the face-gaiter  100 . The shape of the nose detail  12  is such that, in use, the upper and lower vertices  132 ,  134  and the vertical diagonal  136  rest upon and align with the centreline of the user&#39;s nose (see  FIG.  4 C ). It will be appreciated that the nose detail  12  facilitates proper alignment of the face-gaiter  100  on the user&#39;s face. 
     The physical manufacture of the nose detail  12  reduces the perimeter/circumference of the upper circumference  114  of the face-gaiter  10  such that a secure/snug fit for the user is assured where the upper circumference  114  is in contact with the user&#39;s face and head. 
     The fabric extending down from the upper circumference  114  and the nose detail  12  is loose such that the volume defined below the upper circumference  114  and in front of the user&#39;s nose and mouth is generous and the fabric drapes into waterfall folds such that the construction of the front filter  100 A and the neck seal  100 C flows and is loose fitting about the nostrils and mouth area. It will be appreciated; the act of breathing may cause the fabric to move towards the user on inhalation and away from the user on exhalation. However, the configuration of the face-gaiter  100  is such that inhalation and exhalation will have little or no effect on the position of the fabric relative to the user&#39;s face because the looseness of fabric and the volume created below the nostrils and in front of the user&#39;s mouth is such that air pressure directly in front of the mouth is reduced because air flow is encouraged downwards into the area between the user&#39;s neck and the fabric of the face-gaiter  100 . 
     The volume between the user&#39;s neck and the neck seal  100 C is where the face-gaiter  100  is loosest, as such air flow is decelerated as it passes over the folds of fabric into the larger volume. The illustrated configuration improves containment of air flow within the volume defined by the face-gaiter  100  and the user&#39;s face, neck and upper chest. 
     The illustrated face-gaiter  100  is configured to prevent the mask fabric being drawn against the user&#39;s mouth when inhaling hard, which could restrict air flow and be uncomfortable for the user. 
     The upper circumference  114  of the face-gaiter  100  is sized to ensure a secure and sealing fit of the upper circumference  114  against the user&#39;s face in the region across the bridge of the nose (nasion bone), adjacent to the bridge of the nose and the cheek bone (zygomatic bone) area i.e. the area under the user&#39;s eyes. 
     The nose detail  12  creates stiffness in the appropriate area whilst helping to keep the mask fabric off the face in the nostril and mouth area. 
     The rear portion  100 D, as the name suggests, is the portion of the face-gaiter  100  which, in use is at the back/rear of the user&#39;s head i.e. the rear portion  100 D begins and ends at each side of the user&#39;s face, approximately in line with the user&#39;s ears, where the face-gaiter  100  fits closely/tightly to the user&#39;s skin. 
     The rear portion  100 D is a pliable/deformable element of the face-gaiter  100  such that the rear portion  100 D facilitates fitting the face-gaiter  100  by pulling it over the user&#39;s head with ease and also facilitates when, in use, the upper edge of the rear portion  100 D applying a small but consistent tension around the upper circumference of the face-gaiter  100 , such that a top seal  1008  is maintained about the upper circumference and the user&#39;s face even when the user rotates or nods his/her head. 
     At least the upper edge of the rear portion  100 D will stretch in the region of 50% to allow the face-gaiter  100  to be fitted and to maintain a consistent top seal. The construction of the face-gaiter  100  is such that this stretch and recovery is durable over many washes. 
     The neck seal  100 C of the face-gaiter  100  is loose fitting. Therefore, particles and aerosols of a certain size will flow around and within the confines of the face-gaiter  100  and will only escape through any voids i.e. the path of least resistance. As such the porosity of the rear portion  100 D is configured to prevent air flow. The rear portion  100 D may be configured to be impermeable/non-porous by fabric treatment, by bonding a non-porous layer, for example polyurethane to the back portion and/or by adding an impermeable layer, for example natural or synthetic rubber etc. 
     The use of dissimilar fabrics from the triboelectric series can allow a static charge to be created e.g. nylon and polyester. This can be created by additional tumble drying once moisture has been removed. Selecting fabrics that can sustain this static charge while being worn for at least eight hours will maximise the benefit of the additional filtration provided. This could include the addition of polypropylene or polyethylene meshes that provide no other filtration benefit. 
     Heating the filter fabric increases the percentage of water-based aerosols that are filtered. Running low voltage heating wires through the fabric in the filter layer  120 A can be used to generate this heat. These wires could be run off rechargeable batteries fitted to or remotely from the face-gaiter  100  or when suitable (for example when working at a desk or other fixed location) connected to a low voltage power supply. This power supply could also then recharge the batteries to cover periods of use away from the desk. 
     In each of the illustrated examples, sealing and maintaining a seal between the upper circumference of the face-gaiter  10 ,  100  and the contours of the user&#39;s face and nose is important because any gaps/voids between the user&#39;s face and the upper circumference define a flow path for air flow. For the most part a seal is formed naturally by the upper circumference  14 ,  114  and the nose detail  12  as they fit across the bridge of the nose across and around the cheeks and around the back of the head. A section of material below the upper edge e.g. 25 mm is kept pliable and has enough give/stretch such that the section below the upper circumference follows and hugs the contours of the user&#39;s face and head. However, it will be appreciated that tension in the fabric at each side of the user&#39;s nose creates a triangular gap at each side of the user&#39;s nose. As described above a nose seal e.g.  FIGS.  2 C and  3 D  can fill the gap to ensure the upper circumference is sealed against the contours of the user&#39;s face, nose and head. 
     In one example (see  FIG.  5   ) a nose seal  40  may be provided by two triangular inserts  42 , which are soft and made of deformable foam. In the illustrated example, the inserts  42  are wedge shaped, such that in use they taper (widest part  42 A) from the side of the nose to the face (narrowest part  42 B) to enhance sealing of the upper edge  22  of the face-gaiter  10  against the user&#39;s nose and face. An insert  42  is inserted on each side of the nose detail  20  such that the upper circumference of the face-gaiter  10 ,  100  creates a continuous seal against the user&#39;s face and head. 
     The foam inserts  42  may be covered with fabric e.g. a soft fabric, which facilitates securing the foam insert  42  and distributing pressure about the nose area to ensure a comfortable fit and to prevent soreness/discomfort to the user. 
     Other examples of nose seals  50 ,  60  are illustrated in  FIGS.  6 A to  6 D and  7 A to  7 D . These nose seals  50 ,  60  are manufactured as a single piece, which is shaped to correspond with the profile of a user&#39;s nose. In one example, the nose seal  50 ,  60  may be made from closed cell foam so as to be impermeable to air. The nose seal  50 ,  60  may be manufactured by injection moulding e.g. injection moulded foam. 
     In the illustrated examples, the nose seal  50 ,  60  includes tapered edges  52 ,  62 , a flat base  54 ,  64  and a profiled upper surface  56 ,  66 , which includes a recessed section  58 ,  68  in the centre of the upper surface. The recessed section  58 ,  68  is where the nose seal  50 ,  60  receives the bridge of the nose (nasion bone) when the face-gaiter  10 ,  100  is worn. 
     The shape and material of the nose seal  50 ,  60  is such that it can be relatively easily inserted during manufacture of the face-gaiter  10 ,  100  and that it deforms suitably to create a seal about the user&#39;s nose area. The deformability of the seal material is such that the configuration of the nose seal  50 ,  60  is suitable for use by user&#39;s with varying nose and cheek profiles. 
     For optimum comfort and to ensure an optimum seal, the nose seal  50 ,  60  can be made to suit the nose profile of a specific user e.g. by scanning the user&#39;s face and using additive manufacturing (rapid manufacturing) to make a single customised nose seal  50 , of the type illustrated in  FIG.  6 A to  6 D , but with a profiled upper surface that conforms to the shape of the user&#39;s nose to cheek area. The recessed section  58  is shaped such that the nose seal  50  rests on the bony upper part of the bridge of the nose such that air flow through the user&#39;s nasal passages is not restricted. 
     The ability to filter aerosols down to at least 0.3 um with little or no leaks and the ability to be washable potentially hundreds of times makes the face-gaiter  10 ,  100  a viable alternative to disposable occupational masks especially those aimed at protection from specific types of dust and airborne particles. The whole life costs of such face-gaiters  10 ,  100  would be lower, they can be branded for promotion and recycled at end of life offering significant environmental benefits. 
     The face-gaiter  10 ,  100  may provide some relief to sufferers from pollen and other organic airborne particles. Wearing a face-gaiter  10 ,  100  will filter many of these from the air, is likely to reduce the amount of time the user breathes through his/her nose and will help to maintain a humid environment that reduces irritation of the airways. 
     The highly breathable fabric and deformable nature of the construction used in the face-gaiter  10 ,  100  means that it is possible for a user to wear the face-gaiter  10 ,  100  whilst sleeping comfortable in the knowledge they can sleep in any position without the risk of reduced oxygen take up. 
     At low levels of respiration, such as resting or sleeping, the air temperature within the mask remains close to the ambient air temperature making it extremely comfortable to wear and the general impression is one of not wearing a mask at all. This also makes it suitable for a patient who is bed ridden or otherwise has limited mobility. 
     Air pressure can be further reduced by increasing the area of fabric filtering the air and selecting a fabric with higher permeability. This should be done while maintaining the required level of filtration (defined by the percentage containment achieved at a minimum particle size). Containment performance should be measured for the mask and not just for the fabric. 
     To reduce muffled sounds the face-gaiter  10 ,  100  may include a layer of acoustically transparent non-breathable material close to the user&#39;s mouth. 
     To facilitate viewing facial expressions, for example to allow lip reading, the face-gaiter  10 ,  100  may include a clear panel in front of the user&#39;s mouth. Heating wires may be embedded in the panel to minimise fogging such that visibility of the user&#39;s mouth is not impaired. 
     It will be appreciated, the bottom seal/neck seal in each example is created by the natural weight and loose configuration of the fabric of the face-gaiter  10 ,  100 . However, the neck seal  10 B,  100 C may be broken if the positive pressure of the air inside the face-gaiter  10  is too high which could occur if the porosity of the front filter area i.e. the upper portion  10 A or front filter  100 A is too low. To ensure an adequate bottom seal/neck seal, the lower edges  23 ,  17 ;  123 ,  117  can be tucked inside a user&#39;s neck line of a top/t-shirt or weights can be added to the lower edges  23 ,  17 ;  123 ,  117  to ensure the lower edges are not disturbed by movement of the user&#39;s head or by increased air flow/air pressure. 
     The neck seal may be enhanced by attaching a donut of fabric (not illustrated), for example non-porous fabric to the lower edge of the mask and attaching a mechanism, similar to braces, to the donut to pull the lower edge into contact with the shoulder, back and chest region. This will significantly increase the internal pressure required for the lower seal to fail and will also maintain the seal during activities that involve the user bending at his/her waist. 
     When wearing a mask/face-gaiter  10 ,  100  for extended periods of time, the shape and configuration of the forward portion of the face-gaiter  10 ,  100  improves user comfort compared with conventional masks because the effort required to breathe through the face-gaiter  10 ,  100  for any given material is reduced. The area/volume provided by the front portion of the face-gaiter  10 ,  100  effectively reduces the peak pressure on the filter layer. This allows the filter layer  80 ,  120 A to contain a greater percentage of the particles of any given size compared with conventional masks. Therefore, when comparing like for like filter fabrics in the face-gaiter  10 ,  100  and in use with a conventional mask it has been found that the filter material in face-gaiter  10 ,  100  performs better than the same filter material used in a conventional mask. 
     Stitching  90 , as illustrated (see  FIGS.  2 B,  3 A,  3 B,  4 A,  4 B and  4 C ), may be considered problematic because a needle penetrating each layer is likely to leave a hole through which aerosols may escape from behind the face-gaiter  10 ,  100 . However, stitching is an effective way to secure the layers together and will not leave problematic holes if there is sufficient tension in the thread such that the resultant clamping force exerted by the thread as it passes through the layers is sufficiently high to hold the layers tightly together without leaving a hole through which aerosols might escape. 
     Whilst specific embodiments of the present invention have been described above, it will be appreciated that departures from the described embodiments may still fall within the scope of the claims.