WO1998054991A1

WO1998054991A1 - Apparatus and method for enhancing comfort and for fit testing of disposable face masks

Info

Publication number: WO1998054991A1
Application number: PCT/US1998/011418
Authority: WO
Inventors: Joseph A. Rummler; Michael L. Bowen; Kevin K. Brunson
Original assignee: Tecnol Medical Products, Inc.
Priority date: 1997-06-04
Filing date: 1998-06-03
Publication date: 1998-12-10
Also published as: AU7721898A

Abstract

A disposable face mask or disposable respirator including a filter body capable of filtering hazardous materials and/or dangerous airborne pathogens and forming a substantially fluid tight seal between the periphery of the respective face mask or respirator and adjacent portions of a wearer's face. Each disposable face mask or respirator having a filter body with a connector attached thereto and extending therefrom for use in coupling one end of a flexible hose with the respective face mask or respirator. The other end of the flexible hose may be attached to a source of vacuum or a source of low pressure air. For some applications, a single portable source may be used to apply either vacuum or positive low pressure air to the other end of the flexible hose. The connector, flexible hose and source of either vacuum or positive low pressure air improves the apparent breathability and comfort during extended periods of wearing the respective face mask or respirator.

Description

APPARATUS AND METHOD FOR ENHANCING COMFORT AND FOR FIT TESTING OF DISPOSABLE FACE MASKS

RELATED APPLICATIONS

This application is a Continuation-in-Part application of pending U.S. Patent Application Serial No. 08/168,090 filed December 15, 1993, entitled Disposable Face Mask wi th Face Shield, of the same assignee, now abandoned in favor of U.S. Patent Application Serial No. 08/491,137 filed July 17, 1995.

This application is related to U.S. Patent Application Serial No. 08/728,040 filed October 9, 1996, entitled Face Mask wi th Enhanced Facial Seal ; U.S. Patent Application Serial No. 08/571,300 filed December 12, 1995 entitled Face Mask wi th Enhanced Seal and Method; and U.S. Patent No. 5,322,061 and U.S. Patent No. 5,553,608, all of same assignee.

TECHNICAL FIELD OF THE INVENTION

This invention relates generally to apparatus and methods for enhancing comfort while wearing disposable face masks and respirators and/or testing the fit of a disposable face mask or respirator with the face of a wearer. More particularly, bun not by way of limitation, this invention relates to disposable face masks and respirators which form a fluid barrier between the periphery of the mask or respirator and the wearer's f ce. BACKGROUND OF THE INVENTION

Disposable face masks and respirators have been manufactured for many years. In the medical field, most of these masks were previously used in preventing contamination of a patient by the exhaled breath of healthcare personnel. In recent years with increased concern for infection of healthcare personnel by airborne pathogens, such as hepatitis virus B, it has become necessary to prevent not only contamination of patients due to exhalation from healthcare personnel, but also to prevent infection of healthcare personnel from inhaling airborne pathogens. It has become even more important in view of human immunodeficiency virus (HIV) and the increase in infectious tuberculosis associated with HIV patients.

Many surgical style face masks previously had a relatively open or loose fit between portions of the wearer's face and the periphery of the respective surgical style face mask. In recent years, healthcare personnel have shown a preference for wearing disposable face masks which form a fluid barrier or seal between the periphery of the respective face mask and the face of the wearer. As a result of forming this fluid tight barrier, substantially all air that is inhaled or exhaled by the wearer is forced to flow through a filter media associated with the face mask. Since there is little cr no bypass of air between the periphery of such face mas-: and the wearer's face, breathability and comfort durir. periods of long term wear of the face mask have become important factors in selecting disposable face masks :.. : use by healthcare personnel.

Prior face masks when formed from materials with . or poor breathability are generally uncomfortable to ^•.-.- ^•. for long periods of time. Conversely, face masks fcr^~- . from materials with high or good breathability are generally more comfortable to wear for extended periods of time.

It has been found that aerosols having airborne liquid and solid particles are generated not only by the exhalation of infected patients, but also by certain procedural manipulations and processes that impart energy to icrobial suspensions. Also, many viral hemorrhagic fevers such as yellow fever, rift valley fever and perhaps rocky mountain spotted fever, rabies and smallpox can be transmitted through aerosols. A considerable number of studies have been made which are now beginning to identify the transmission of viruses through "non- accident" situations. Accordingly, there is an increased interest in using face masks and respirators which form a substantially fluid tight seal around the periphery of the mask or respirator and at the same time are easy to put on and comfortable to wear. Many face masks previously allowed the passage of fluids and/or aerosols between the periphery of the mask and the wearer's face. The Department of Health and Human Services through the Centers for Disease Control and Prevention are currently preparing "Guidelines For Preventing The Transmission Of Tuberculosis In Health Care Facilities, Second Addition." One of the items which will be emphasized in the new guidelines is personal respiratory protection. The response to the draft guidelines published by the Department of Health and Human Services demonstrates the increased interest and importance of reducing the risk of tuberculosis transmission within health care facilities. The use of personal respiratory protective equipment in areas where there is a risk of exposure to mycobacterium tuberculosis such as tuberculosis isolation rooms where personnel with infectious tuberculosis are isolated is one of the important features of the new guidelines intended to reduce the risk to health care personnel.

The following comments are taken from the draft guidelines as published in the Federal Register, Volume 58, No. 195, Tuesday, October 12, 1993, pages 52843-52845.

"Personal respiratory protection should be used by persons entering rooms where patients with known or suspected infectious TB are being isolated, during cough- inducing or aerosol-generating procedures on patients with known or suspected infectious TB, and in other settings where administrative and engineering controls are not likely to protect persons from inhaling infectious airborne droplet nuclei." Page 52843.

" Face-seal leakage . Face-seal leakage comprises the ability of particulate respirators to protect the worker from airborne material ( 148-ANS I 1980 , 149-Hyattl963, 150—AΝSI1961) . A proper seal between a respirator's sealing surface and a wearer's face is essential for effective and reliable performance of any negative- pressure respirator. It is less critical, but still important, for a positive-pressure respirator. Face-seal leakage can result from factors such as incorrect facepiece size or shape, incorrect or defective facepiece sealing-lip, beard growth on a wearer, perspiration or facial oils that can result in facepiece slippage, failure to use all the headstraps, incorrect positioning of a facepiece on a wearer's face, incorrect headstrap tension or position, improper mask maintenance, and mask damage .

The mechanism of action of negative-pressure (non- powered) particulate respirators is based on the same principle. During each inhalation by a wearer, a negative pressure (relative to the workplace air) is created inside the facepiece of this type of respirator. Due to this negative pressure, air containing contaminants can take a path of least resistance into the respirator — through leaks at the face-seal interface — thus avoiding the higher-resistance filter material. Currently available, cup-shaped, disposable particulate respirators have 0% to 10% (148-ANSI1980) to 20% (151-NIOSH1987, 152-DCCIR1987) face-seal leakage. This leakage through the face seal results from limitations in the design, construction, number of sizes available of these masks, and the variability of the human face. The face-seal leakage is assumed to be even higher if the respirators are not properly fitted to the wearer's face, tested for an adequate fit by a qualified individual, and then checked for fit by the wearer every time these masks are donned. Face-seal leakage may be reduced to less than 10% with improvements in design and more available sizes, combined with appropriate fit testing and fit checking." Page 52844.

"Fit Checking. A fit check is a maneuver that a HC [Added Note: health care worker] performs before each use of the respiratory protective device to check the fit. The fit check can be performed according to the manufacturer's facepiece fitting instructions or using a negative pressure test or a positive pressure test (Table S4-3) .

Some currently available cup-shaped disposable negative-pressure particulate respirators with DATA MINING, DFM, or HEPA filters cannot be reliably fit checked by wearers ( 152-DCCIR1987) , because it is difficult to occlude the entire surface of the filter. Strategies for overcoming these limitations are under development by respirator manufacturers but have not been evaluated." Page 52845.

In addition to health care workers, many industrial applications, such as handling hazardous materials or working in clean room environments, require the use of face masks and respirators that form a substantially fluid tight seal between the face of a wearer and the periphery of the respective mask or respirator. Depending upon factors such as the type of hazardous material, clean room requirements, and/or anticipated airborne pathogen, face masks and/or respirators have previously been attached to a protected source of air.

U.S. Patent 5,368,021, entitled System for Handling and Moni toring Respira tory Waste Streams, states "[a]lthough the endotracheal tube 12 is illustrated as the preferred patient attachment, those of skill in the art would recognize that other conventional attachments, such as a canula and face mask, may also be used." Pending U.S. Patent Application Serial No. 08/555,148 filed on November 18, 1995 entitled Di sposable Mask and Suction Catheter also discusses the use of a vacuum source with surgical style face masks.

Many of the most critical manufacturing procedures associated with advanced electronic equipment such as fabrication of microprocessors and genetically engineered DNA sequences are conducted in clean room environments. Continuing advances in fabricating very small but highly complex integrated electrical circuits from a wide variety of semiconductor materials and truly remarkable breakthroughs in genetic engineering have resulted in cleanliness standards of three or four hundred particles per cubic meter of air which were acceptable ten years ago being unacceptable today. For example, many very large scale integrated circuits require fabrication in a clean room environment with contamination levels in the range of approximately one to ten particles per cubic meter of air.

As clean room standards have become more stringent, protective clothing worn by personnel working in such clean rooms has become more elaborate and often more expensive. Typically, clean room garments and accessory equipment have been reused following appropriate cleaning after each prior use. A typical clean room garment would be a lab coat or jacket fabricated from one or more layers of expanded polytetrafluoroethylene (PTFE) and encapsulated on each side by a close knit polyester woven or textile type material. The associated clean room garment was often formed from such materials by cutting and sewing. As various types of tape and other adhesives have been used to cover the resulting seams to further minimize potential contamination of the clean room environment. One type of plastic film material used for such applications includes Gortex - available from -. Until only recently, most clean room protective clothing was reusable and required cleaning after each use. The effectiveness of such protective garments for clean roor. applications is often determined by using the Helmke drur test. Some manufacturers refer to the particulate leve. generated by the Helmke drum test in marketing their clean room garments and accessory equipment.

During the past few years, more disposable product are being used in clean room applications. Many of t^'r.-- disposable products are the same as the disposable products used in medical and healthcare industry. SUMMARY OF THE INVENTION

In accordance with the present invention, apparatus and methods are provided to substantially reduce or eliminate shortcomings previously associated with long term wear of disposable face masks and/or disposable respirators in potentially hazardous environments. The present invention provides simple, reliable apparatus for checking the facial fit of a disposable face mask or disposable respirator with the face of a wearer. The present invention also provides simple, reliable apparatus for enhancing comfort while wearing a disposable face mask or disposable respirator that forms a substantially fluid tight seal between the periphery of the respective face mask or respirator and adjacent portions of the wearer's face. The present invention results in reliable, cost effective apparatus and methods to enhance comfort or to check facial fit of a disposable face mask or disposable respirator.

One aspect of the present invention includes providing a connector which may be used to releasably couple a flexible hose with a disposable face mask or disposable respirator that forms a substantially fluid tight seal between the periphery of the respective face mask or respirator and adjacent portions of the wearer's face. The other end of the flexible hose may be attached to a fixed source of vacuum such as typically associated with a surgical operating room or a fixed source of positive low pressure air. For some applications, the other end of the flexible hose may be attached to either a portable source or a fixed source of positive low pressure air. Depending upon the anticipated working environment for the respective disposable face mask or disposable respirator, the volume of low pressure air supplied through the flexible hose to the wearer or the amount of vacuum applied to the flexible hose may be varied to optimize performance of the associated disposable face mask or respirator for protection of the wearer. As a result of the present invention, various materials which offer excellent protection from airborne pathogens and/or hazardous materials, but have less than desired breathability for use in conventional disposable air masks or disposable respirators, may now be satisfactorily used with a face mask or respirator incorporating teachings of the present invention.

Technical benefits of the present invention include optimizing the filtration capability of a disposable face mask or disposable respirator to resist the passage of potentially hazardous liquids, particulate matter and/or aerosols while at the same time minimizing resistance to normal breathing by a wearer and providing a comfortable fit during extended periods of wear. The present invention allows using one or more layers of selected filter media designed to block the passage of a specific type of hazardous material even though the selected filter media may not have the necessary breathability for use in conventional disposable face masks and disposable respirators .

Further technical advantages of the present invention include providing apparatus and methods which may be used with a wide variety of disposable face masks and disposable respirators including molded cone-style face masks or respirators and modified cone-style face masks or respirators having both a molded portion and a portion formed from one or more layers of flexible material . BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention and for the advantages thereof, reference is now made to the following description taken in conjunction with the accompanying drawings, in which: FIGURE 1 is a schematic drawing showing a perspective view of a disposable face mask or a disposable respirator on the head of a wearer and a flexible hose coupling the face mask or respirator to a permanently installed vacuum source at a medical facility or industrial facility in accordance with teachings of the present invention;

FIGURE 2 is a schematic drawing in section and elevation with portions broken away showing the disposable face mask or disposable respirator of FIGURE 1 and a connector extending through the filter body of the disposable face mask or disposable respirator for use in coupling the face mask or respirator with either a source of vacuum or a source of positive low pressure air; FIGURE 3 is an enlarged drawing partially in section and partially in elevation with portions broken away showing a connector for coupling a disposable face mask or disposable respirator with a flexible hose in accordance with teachings of the present invention; FIGURE 4 is a schematic drawing showing a perspective view of another type of disposable face mask worn on the head of a wearer with a flexible hose coupling the face mask to a portable source of either vacuum or positive low pressure air; FIGURE 5 is a schematic drawing showing a front plan view of the face mask of FIGURE 4 with portions broken away and a connector extending through the filter body of the face mask for using in coupling the face mask with either a source of vacuum or a source of positive low pressure air;

FIGURE 6 is an enlarged schematic drawing showing an exploded view of an alternative connector which may be releasably secured with multiple layers of material used to form either a disposable face mask or a disposable respirator with a portion of the connector extending therefrom for coupling the disposable face mask or respirator with a flexible hose; and FIGURE 7 is a schematic drawing showing an elevational view of a portable source of either positive low pressure air or vacuum satisfactory for use with disposable face masks and disposable respirators in accordance with teachings of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The preferred embodiments of the present invention and its advantages are best understood by referring to FIGURES 1-7 of the drawings, like numerals, being used for like and corresponding parts of the various drawings. Disposable face masks 10 and 100 incorporating various features of the present invention may be used to retard the flow of bacteria, liquids, particulate matter, aerosols and/or hazardous materials from the exterior of the respective mask to the nose and mouth of a wearer. Disposable face mask 10 may also be referred to as a "disposable respirator." Further information concerning disposable face mask 10 may be found in U.S. Patent 5,322,061, entitled Disposable Aerosol Mask . Further information concerning face mask 100 may be found in U.S. Patent 5,553,608, entitled Face Mask wi th Enhanced Fl uid Seal and Method. Both of these patents are incorporated by reference for all purposes within this application.

The terms "disposable face mask(s)" and "disposable respirator (s) " are intended to include any disposable surgical style face mask or disposable industrial-type respirator that forms a substantially fluid tight seal between the periphery of the respective face mask or respirator and adjacent portions of the wearer's face. Other types of disposable respirators satisfactory for use with the present invention include molded cone style face masks, such as shown in U.S. Patent 4,641,645, entitled Face Mask and modified cone-style face masks such as shown in U.S. Patent 3,688,768 entitled Di sposable Face Mask Respira tor and Method of Making Same . Both of these patents are incorporated by reference for all purposes within this application. Unless expressly stated otherwise, the terms "disposal . face mask" "face mask" and "mask" are used in the claims indicate both face mask and respirators as discussed in this application.

The term "substantially fluid tight seal" is used to indicate that the acceptable amount of leakage or bypass fluid flow between the periphery of the respective face mask or respirator and adjacent portions of the wearer's face is dependent upon the intended working environment. For some hazardous material conditions and/or extremely dangerous airborne pathogens only zero leakage may be acceptable. For other less hazardous conditions and/or less dangerous airborne pathogens, a somewhat higher amount of leakage may be acceptable between the periphery of the respective face mask or respirator and adjacent portions of the wearer's face. The present invention allows manufacturing a face mask or respirator having the required fluid tight seal with portions of the wearer's face from materials which will provide the necessary degree of filtration protection depending upon the anticipated working environment and at the same time enhancing comfort while wearing the respective face mask or respirator for extended periods of time.

For purposes of this application, aerosols are defined as insoluble liquids or particulate matter frequently associated with microbial solutions. The term "fluid" is used within this application to include any gas, liquid, or mixture of gases and liquids along with various types of particulate matter and aerosols which may be entrained with such fluids. For purposes of this application, the terms

"breathable" and "breathability" are used with respect to evaluating materials for use in fabricating a face mask and/or respirator that will not significantly restrict normal breathing of a wearer while performing routine tasks. For example, face masks often have filter bodies formed from materials with breathability measured in the range of approximately one to five millimeters of water at thirty-two liters per minute of air flow. Requirements for breathable materials or breathability satisfactory for fabricating a face mask or respirator are substantially different from materials used to fabricate various types of clothing such as surgical gowns, lab coats, head coverings and other protective garments which may also be described as "breathable" but actually require only a very small amount of air passage therethrough as compared to face masks and respirators.

For purposes of this application, the term "positive, low pressure air" is used to indicate air at a pressure greater than atmospheric pressure but at a sufficiently low pressure to allow comfortable breathing of the air. The term "vacuum source" is issued to indicate a source of negative pressure which is less than atmospheric pressure and will create a flow of air that allows comfortable breathing.

Mask 10 incorporating some of the teachings of the present invention in shown in FIGURE 1 positioned on the face of wearer 12 who is illustrated in ghost lines. Mask 10 includes filter body 14 which may be secured to wearer 12 by resilient securing members or headbands 16 and 18. Filter body 14 comprises an upper portion 20 and a lower portion 22 with each portion having a generally trapezoidal configuration. Upper portion 20 and lower portion 22 preferably have generally matching exterior dimensions and shape. Upper and lower portions 20 and 22 may be bonded together by heat and/or ultrasonic sealing along three sides of filter body 14. Bonding in this manner adds structural integrity to mask 10. The fourth side of filter body 14 is open and preferably includes top edge 24 with elongated malleable member 26 (see FIGURE 2) and bottom edge 28. Malleable member 26 may be provided so that top edge 24 of mask 10 can be configured to closely fit the contours of the nose and cheeks of wearer 12. Malleable member 26 is preferably constructed from an aluminum strip with a rectangular cross-section, but may also be a moldable or malleable steel or plastic member. As shown in FIGURE 2, top edge 24 may be faced with edge binder 36 that extends across the open end of mask 10 and covers malleable strip 26. In a similar manner, bottom edge 28 may be encompassed in edge binder 38. Edge binders 36 and 38 are preferably constructed from a spun-laced polyester material. Binders 36 and 38 may also be constructed from a number of thermally bonded bicomponent materials or from polypropylene or polyethylene non-porous plastic films.

Top edge 24 of upper portion 20 and bottom edge 28 of lower portion 22 cooperate with each other to define the periphery of mask 10 which contacts adjacent portions of the face of wearer 12. The present invention allows testing the fluid barrier formed between the periphery of mask 10 and the adjacent portions of the face of wearer 12 and optimizing the filtration capability of mask 10 to resist the passage of liquids, particulate matter and aerosols through filtration media 34 while minimizing resistance to normal breathing of wearer 12 during extended period of wearing mask 10. The present invention also allows including one or more layers of filter media within filter body 14 formed from materials which are not normally considered breathable for purposes of fabricating a face mask. As shown in FIGURES 1 and 2, mask 10 has a configuration somewhat similar to a cup or cone when placed on the face of wearer 12. Therefore, comments with respect to incorporating teachings of the present invention into mask 10 and the resulting benefits apply to molded cone-style face masks or respirators and modified cone-style face masks or respirators.

As shown in FIGURES 1 and 2, a portion of connector 50 extends from lower portion 22 of filter body 14 for use in coupling one end 62 of flexible hose 64 with face mask 10. The other end 66 of flexible hose 64 may be attached to either a source of vacuum or a source of positive low pressure air. For the embodiment of the present invention as shown in FIGURE 1, end 66 of flexible hose 64 is attached to permanently installed piping system 68 which in turn is connected to fixed source of vacuum 70. Depending upon the intended working environment and potentially hazardous materials and/or airborne pathogens, piping system 68 may be manufactured from a wide variety of metal alloys, plastic compounds and/or composite materials typically associated with such piping system.

For some applications, piping system 68 and vacuum source 70 may be the same as or similar to vacuum systems typically included in a hospital as part of a surgical operating room. Alternatively, piping system 68 may be connected to a fixed source of positive low pressure air often found at industrial facilities in locations associated with possible exposure to potentially hazardous materials and/or airborne pathogens. Piping system 68 preferably includes multiple nozzles 72 for attachment with end 66 of flexible hose 64. When not in use, cap 74 is preferably placed on each nozzle 72. Piping system 68 and/or vacuum source 70 preferably include extensive filtration systems (not expressly shown) to eliminate or substantially minimize any discharge of potentially hazardous materials and/or airborne pathogens from vacuum source 70. For some applications, flexible hose 64 may be used to attached face masks 10 and 100 with a source of vacuum to test the fit between the respective periphery of faces mask 10 and 100 and adjacent portions of the face of wearer 12. An example of one type of testing system having a vacuum source is shown in U.S. Patent 4,765,325 entitled Method and Appara tus for Determining Respira tor Face Mask Fi t . Alternatively, flexible hose 64 may be used to attach face masks 10 and 100 with a system for sampling, handling and disposing of respiratory waste from a patient under medical care. One example of such a system including a source of vacuum is shown in U.S. Patent 5,368,021 entitled System for Handling and Moni toring Respira tory Waste Streams . Both of these patents are incorporated by reference for all purposes within this application.

Flexible hose 64 may also be used to attach face ■masks 10 and 100 with a fixed source (not expressly shown) of positive low pressure air. When working in environments associated with highly toxic airborne chemicals or extremely dangerous airborne pathogens, it is often preferable to provide a positive flow of low pressure air to face masks 10 and 100. The fixed so rc- of positive low pressure air may be located outside t^'r. hazardous environment and may include multiple filter:.". : systems (not expressly shown) to substantially reduce eliminate any possibility of contamination of air supplied to wearer 12.

Depending upon the intended application for the associated face mask or respirator, flexible hose 64 .- . be relatively short (less than approximately 8 to 10 feet) or may be substantially long (10 feet and greater) . Also, flexible hose 64 may be formed from various elastomeric and/or rubber compounds compatible with the intended environment in which the associated face mask or respirator will be used. For other applications particularly involving extremely hazardous materials and/or airborne pathogens, flexible hose 64 may include one or more layers of armor protection to substantially minimize or eliminate possible cutting or damaging of the associated flexible hose 64.

Since the opening or periphery of face mask 10 defined in part by top edge 24 and bottom edge 28 forms a substantially fluid tight seal with adjacent portions of the face of wearer 12, attaching flexible hose 64 to either a source of vacuum or a source of positive low pressure air results in wearer 12 breathing only air which has either past through filter media 34 or through flexible hose 64. When flexible hose 64 is attached to a vacuum source such as fixed vacuum source 70, an increased air flow, depending upon various factors such as flow characteristic of each specific vacuum source 70 and piping system 68 and breathability of filter body 14, will be drawn through mask 10. The increased air flow provides more comfort to wearer 12 by effectively increasing the supply of cool, fresh air and removing exhaled warm air when wearer 12 is inhaling and exhaling, respectively, as compared to when vacuum source 70 is not available. The effective increase in apparent breathability of the filter media also adds to the comfort of wearing face mask 10 for extended periods of time .

In a similar manner, supplying positive, low pressure air through flexible hose 64 to face mask 10 improves comfort when wearer 12 is both inhaling and exhaling through filter body 14. Examples of equipment associated with attaching a protective hood or a respirator with a source of positive low pressure air (both fixed and portable) are shown in U.S. Patent

4,683,880 entitled Toxic Fume Protecti on Hood and Method of Construction . This patent is incorporated by reference for all purposes within this application.

As illustrated in FIGURE 2, upper and lower portions 20 and 22 may include respective outer layers 30 preferably constructed from a spun-bonded polypropylene. Outer layers 30 may also be constructed from a bi- component and/or powder bonded material such as polyethylene or polypropylene, a cellulastic tissue, or a spun-bonded polyester. Outer layers 30 typically have a basis weight range of 0.5 ounces per yard to 1.0 ounces per yard. 0.9 ounces per yard is one of the preferred basis weights for outer layers 30.

Inner layers 32 are preferably composed of a bicomponent polyethylene and polypropylene. Inner layers 32 may also be constructed from polyester and/or polyethylene material or cellulastic tissue. Inner layers 32 typically have a basis weight range of 0.4 ounce per yard to 0.75 ounces per yard. 0.413 ounces per yard is one of the preferred basis weights for layers 32. One or more intermediate layers of filter media 34 may be disposed between outer layers 30 and inner layers 32. Selection of the number and type of intermediate layers of filter media 34 will depend upon the intended working environment for mask 10.

In FIGURE 2, filter body 14 is shown with only one layer of filter media 34 in both upper portion 20 and lower portion 22. Filter media 34 may often be constructed from a melt-blown polypropylene, an extruded polycarbonate, and/or a melt-blown polyester. A melt- blown urethane may also be used to form all or a part of filter media 34. Installing connector 50 in lower portion 22 of filter body 14 and attaching the associated face mask 10 with vacuum source 70 in accordance with teachings of the present invention substantially increases the apparent breathability and comfort during extended periods of wear when filter body 14 has been fabricated from the previously described materials or any other materials appropriate for the intended environment in which face mask 10 will be worn.

Connector 50, flexible hose 64 and vacuum source 70 cooperate with each other such that wearer 12 is exposed to a desired volume of air flowing through filter body 14 without requiring only inhaling and exhaling by wearer 12 to develop the full differential pressure to permit air flow through filter body 14, even though layers 30, 32 and 34 may be formed from materials which block particles substantially smaller than one micron and face mask 10 may form a very tight fluid seal with the face of wearer 12.

Connector 50 is shown in more detail in FIGURE 3. Connector 50 includes enlarged flange 54 having a generally circular configuration with one end of elongated hollow tube 52 extending therefrom. A plurality of threads 56 are preferably formed on the exterior of hollow tube 52 intermediate the ends thereof. Nut 58 includes an opening extending therethrough with matching threads 56 formed on the interior of the opening. The size of the opening formed in nut 58 is selected to be compatible with the exterior of hollow tube 52 such that threads 56 formed on the interior of the opening in nut 58 may be engaged with matching threads 56 formed on the exterior of hollow tube 52. Hollow tube 52 includes longitudinal bore 60 extending therethrough. End 61 of hollow tube 52 opposite from enlarged flange 54 is sized to be received within end 62 of flexible hose 64. For some applications, serrations (not expressly shown) may be formed on the exterior of hollow tube 52 adjacent to end 61 to more securely couple flexible hose 64 with connector 50. Also, various types of hose clamps (not shown) may be used to more securely couple flexible hose 64 with connector 50 particularly when working in environments with extremely hazardous materials and/or airborne pathogens. For some applications, an annular groove (not expressly shown) may be formed in interior surface 55 of enlarged flange 54 or interior surface 59 of nut 58 to receive a sealing member such as an O-ring to enhance the fluid tight seal formed between enlarged flange 54, nut 58 and layers 30, 32 and 34 of lower portion 22 disposed therebetween.

Aperture or opening 40 is preferably formed within lower portion 22 of filter body 14 and sized to be compatible with the exterior of hollow tube 52. The longitudinal spacing between interior surface 55 of enlarged flange 54 and interior surface 59 of nut 58 when matching threads 56 are engaged is selected to be less than the nominal thickness of lower portion 22 adjacent to aperture 40. Thus, when nut 58 is engaged with threads 56 on the exterior of hollow tube 52, adjacent portion of material layers 30, 32 and 34 of lower portion 22 will be trapped between interior surfaces 55 and 59 and compressed to form a substantially fluid tight seal between an exterior portion of hollow tube 52 defined by interior surfaces 55 and 59 and portions of filter body 14 adjacent to aperture 40. Both flange 54 and nut 58 are shown having a generally circular configuration. For some applications, the geometric configuration of enlarged flange 54 and/or nut 58 may be modified to have a rectangular, square, hexagonal or any other geometric configuration as appropriate for the associated face mask. Also, hollow tube 52 is shown extending in a substantially normal, straight direction with respect to interior surface 55 of enlarged flange 54. For some applications, the angle between flange 54 and hollow tube 52 may be varied to accommodate the associated face mask. Also, hollow tube 54 may include one or more bends intermediate the ends thereof, depending upon the requirements of the associated face mask and/or flexible hose which may be attached to hollow tube 52.

Mask 100 incorporating an alternative embodiment of the present invention is shown in FIGURES 4 and 5. Mask 100 includes filter body 114 with flaps or sheets of flexible material 102 and 104 extending from respective lateral edges 106 and 108 filter body 114. Filter body 114 also includes top edge 124 and bottom edge 126 with lateral edges 106 and 108 extending therebetween. For some applications, filter body 228 may be fabricated in general as described in U.S. Patent 4,635,628 entitled Surgical Face Mask wi th Improved Moisture Barrier and

U.S. Patent 4,969,457 entitled Body Fl uids Barri er Mask . Both of these patents are incorporated by reference fcr all purposes within this application.

For some applications, flaps 102 and 104 are preferably formed from fluid impervious material folce : with a generally U-shaped cross section. Flaps 102 a.- : 104 may sometimes be referred to as C-folds. For otr.-_r applications, flaps 102 and 104 may be formed from polyethylene film laminated with a non-woven material . The non-woven material may also be hydroentangled. For still other applications, the polyethylene film may be laminated to any type of material as desired. The polyethylene film layer may be color coded to correspond with different application^ for using the resulting face mask. Alternatively, flaps 102 and 104 may be formed from resilient and/or stretchable materials. Such resilient materials include thermoplastic rubber compounds which may be extruded or injection molded as strips or sheets of material. An example of such thermoplastic rubber compounds is available under the trademark KRATON© from Shell Oil Company. A breathable type film may also be used to fabricate flaps 102 and 104. One of the benefits of the present invention is the ability to fabricate flaps 102 and 104 from materials that have lower cost as compared to the materials used to form filter body 114. Alternatively, flaps 102 and 104 may be formed from one or more of the same materials used to fabricate filter body 114.

Filter body 114 and flaps 102 and 104 are preferably designed to prevent or retard the passage of liquids from the exterior of mask 100 to the face of wearer 12. It is extremely difficult to construct a mask that will fit the facial configuration of all wearers without constructing the mask specifically for each individual face. The use of flaps 102 and 104 greatly increases the different sizes and types of faces which can be effectively protected by mask 100. Forming flaps 102 and 104 from suitable resilient or stretchable material further improves facial fit with a large number of wearers.

Filter body 114 may comprise a plurality of pleats 110, 111 and 112 which allow expansion of filter body 114 to cover the mouth and nose of wearer 12. The number of pleats 110, 111 and 114 formed in filter body 114 may be varied to provide the desired fit with the face of wearer 12. Pleat 112 is preferably folded in a reverse direction as compared to pleats 111 and 110. By providing reverse pleat 112, filter body 114 has an increased tendency to stand away from the face of wearer 12. The dimensions and configuration of pleats 110, 111 and 112 may be varied to accommodate engaging connector 150 with filter body 114. For some applications filter body 114 may be formed without pleats. For other applications, filter body 114 may be formed with non-collapsing face panels such as shown in U.S. Patent 4,606,341 entitled Non-Collapsible Surgical Face Mask . U.S. Patent 4,606,341 is incorporated by reference for all purposes within this application. For still further applications, filter body 114 may be formed from only one layer of material or from multiple layers of material, some of which may have breathability characteristics previously considered undesirable for face masks. Flexible hose 64, connector 150 and portable source 170 of either vacuum or positive low pressure air allow a wide variety of options in selecting material with adequate breathability and high resistance to passage of hazardous materials and/or airborne pathogens for fabricating filter body 114.

The use of reverse pleat 112 in cooperation with pleats 111 and 110 forms a large breathing chamber as compared to many other soft, pleated style masks which contact a substantial portion of a wearer's face. The larger breathing chamber permits cooler and easier breathing associated with "off-the-face" style mask such as shown in U.S. Patent 4,606,341. Flexible hose 64, connector 150 and portable source 170 of either vacuum or positive low pressure air allows optimizing the volume of air contained within filter body 114 without sacrificing comfort to wearer 12 or filtration efficiency.

As shown in FIGURES 4 and 5, a portion of connector 150 extends from the lower portion of filter body 114 for use in coupling end 62 of flexible hose 64 with face mask 100. The other end 66 of flexible hose 64 may be attached to either a source of vacuum provided by air inlet 176 of portable source 70 or a source of positive low pressure air provided by air outlet 178 of portable source 170. For some applications, end 66 of flexible hose 64 may be attached to a permanently installed piping system such as previously described with respect to face mask 10.

Depending upon the intended working environment and potentially hazardous materials- and/or airborne pathogens, portable source 170 and air inlet 176 and air Outlet 178 may be manufactured from a wide variety of metal alloys, plastic compounds and/or composite materials typically associated with portable sources of either positive low pressure air and/or a source of vacuum. Portions of air inlet 176 and air outlet 178 may include a plurality of tapered serration 180 to receive end 66 of flexible hose 64 and to prevent accidental disconnection of hose 64. Various types of portable pumps, air compressors and/or air blowers may be satisfactorily used to provide portable source 170. For some applications, the dimensions and weight of portable source 170 are selected to allow wearer 12 to carry portable source 170 in a back pack or attached to an appropriately sized belt. For such applications, portable source 170 will preferably include battery power supply 168. For other applications, portable source 170 may be placed on an appropriately sized cart or carrier (not shown) and may include portions of piping system 68 such that more than one wearer may use portable source 170. For the embodiment shown in FIGURE 4 and 7, portable source 170 includes HEPA type filter 172. Other types of filters and filtering systems may be used with portable source 170. One type of portable source of vacuum or positive low pressure air satisfactory for use with the present invention is available from Racal Health and Safety.

Since the periphery of face mask 100 defined in part by top edge 124, bottom edge 126 and flaps 102 and 104 along with respective lateral edges 106 and 108 forms a substantially fluid tight seal with adjacent portions of the face of wearer 12, attaching flexible hose to either a source of vacuum such as air inlet 176 or a source of positive low pressure air such as air outlet 178 will result in wearer 12 breathing only air which has either passed either through filter body 114 or HEPA filter 172 and flexible hose 64. When flexible hose 64 is attached to air inlet 176, increased flow of air, depending upon such factors as flow characteristics of each portable source 170 will be drawn through filter body 114. The increased air flow will assist wearer 12 by increasing the comfort when wearer 12 is both inhaling and exhaling through filter body 114 as compared to when portable source 170 is not available. In a similar manner, supplying positive low, pressure air from air outlet 178 through flexible hose 64 to face mask 100 improves comfort when wearer 12 is both inhaling and exhaling through filter body 114. As illustrated in FIGURE 5, filter body 114 may include multiple layers of material such as outer layer 130, inner layer 132, filter media 134 and barrier layer 136. Outer layer 130 may be formed from the same materials as previously discussed with respect to outer layers 30 of face mask 10. In a similar manner, inner layer 132 and filter media 134 may be formed from the same materials as previously discussed with respect to inner layers 32 and filter media 34 of face mask 10. As shown by the cutaway portion of FIGURE 5, filter body -114 includes four layers of material with an external surface of cover stock 130 as the outermost layer. Inner layer or internal surface 132 which contacts the face of wearer 12 may be constructed of a light weight, highly porous, softened, non-irritating, non-woven fabric, such as Dexter, Inc. product No. 3768. Inner layer 132 is designed to prevent unwanted materials such as facial hair, loose^' fibers or perspiration from contacting layers 136 and 134 which might cause a wicking effect to draw liquids through filter body 114. Inner layer 132 also provides a comfortable surface for contact with the face of wearer 12.

Filter body 114 may be formed by bonding layers 130, 132, 134 and 136 with each other in a generally rectangular configuration. Such bonding is preferably provided along top edge 124, bottom edge 126 and lateral edges 106 and 108, respectively. The bonded areas may be formed by sewing, glue, heat sealing, welding, ultrasonic bonding and/or any other suitable bonding procedure. Flaps 102 and 104 are preferably integrally attached to filter body 114 as part of the respective bonded areas. Bonded areas 120 and 122 may be used to attach securing means 116 and 118 at approximately the mid-points of respective flaps 102 and 104. Top edge 124 of filter body 114 preferably includ-.- elongated malleable member 26 so that top edge 124 of filter body 114 can be configured to closely fit the contours of the nose and cheeks of wearer 12. Top edge 124, bottom edge 126 and flaps 102 and 104 cooperate .-.. ^■ each other to define the periphery of mask 100 which contacts adjacent portions of the face of wearer 12.

Connector 150 is best shown in FIGURE 6. Connector 150 includes enlarged flange 154 with elongated hollow tube 152 extending therefrom. Hollow tube 152 and enlarged flange 154 are similar to hollow tube 52 and enlarged flange 54 as previously described with respect to connector 50, except hollow tube 152 has a generally uniform, smooth exterior surface and does not include threads 56 formed intermediate the ends thereof.

Slidable clasp 158 preferably includes opening 157 extending therethrough. Opening 157 is preferably slightly smaller than the outside diameter of hollow tube 152. Multiple cuts or serrations 159 extend from opening 157 into slidable clasp 158 to form a plurality of flexible locking tabs 162. Serrations 159 and locking tabs 162 cooperate with each other to form a small truncated cone extending from outer surface 156 of slidable clasp 158. The orientation and size of locking tabs 162 is selected to allow clasp 158 to slide relatively easily over the exterior of elongated hollow tube 152 towards interior surface 155 of enlarged flange 154. This same configuration of serrations 159 and locking tabs 162 prevents or restricts movement of slidable clasp 158 longitudinally away from enlarged flange 154 toward end 161 of hollow tube 152. Slidable clasp 158 is relatively thin as compared to nut 58 of connector 50.

Hollow tube 152 preferably includes a longitudinal bore extending therethrough similar to longitudinal bore 60 of connector 50. End 161 of hollow tube 152 is sized to be received within end 62 of flexible hose 64. For some applications, serrations (not expressly shown) may be formed on the exterior of hollow tube 152 adjacent to end 161 to more securely couple flexible hose 64 with connector 50, particularly when working in environments with extremely hazardous materials and/or airborne pathogens. For some applications, an annular groove (not expressly shown) may be formed in interior surface 155 of enlarged flange 154 to receive a sealing member such as an O-ring to enhance the substantially fluid tight seal formed between enlarged flange 154, slidable clasp 158 and the layers of filter body 114 disposed therebetween. As shown in FIGURE 6, aperture or opening 140 is preferably formed within the lower portion of filter body 114 and sized to be compatible with the exterior of hollow tube 152. Connector 150 is attached to filter body 114 by inserting end 161 of hollow tube 152 through opening 140 until interior surface 155 of enlarged flange 154 contacts inner layer 132 of filter body 114. Opening 157 of slidable clasp 158 may then be inserted over end 161 of hollow tube 152. As previously noted, serrations 159 and locking tabs 162 allow slidable clasp 158 to move longitudinally over the exterior surface of hollow tube

150 toward interior surface 155. Interior surface 155 on enlarged flange 154 faces a corresponding interior surface of slidable clasp 158.

Serrations 159 and locking tabs 162 adjacent to opening 157 are oriented such that, when the material layers of filter body 114 are compressed between enlarged flange 154 and slidable clasp 158, a substantially fluid tight seal is formed with the exterior portion of hollow tube 152 disposed therebetween. Cooperation between serrations 159 and locking tabs 162 adjacent to opening 157 prevent or restrict movement of clasp 158 longitudinally away from enlarged flange 154 and thus, maintain the desired fluid tight seal. Installing connector 150 in the lower portion of filter body 114 and attaching face mask 100 with portable source 170, in accordance with teachings of the present invention, substantially increases the apparent breathability and comfort during extended periods of wear when filter body 114 and flaps 102 and 104 have been .fabricated from the previously described materials.'

Connector 150 may be satisfactorily used with mask 10 or any other type of face mask or respirator. In the same manner, connector 50 may be satisfactorily used with mask 100 or any other type of face mask or respirator. For some applications, connectors 50 and 150 may be used with face masks such as conventional surgical style face mask that do not form a complete fluid tight seal between the periphery of the respective mask and the wearer's face. Even though such face masks have substantial leakage or by-pass flow of air between the perimeter of the respective face mask and the wearer's face, applying either a source of vacuum or positive low pressure air to such face masks using connector 50 and/or 150 will improve comfort during periods of extended wear. Connectors 50 and 150 are available from TSI Incorporated located at 500 Cardigan Road, Saint Paul, Minn. 55164 for use in testing the fit of face masks and respirators with a wearer's face.

The present invention allows optimizing the volume of air contained within filter body 14 and 114 and the breathability of respective material layers 30, 32, 34 and material layers 130, 132, 134 and 136. If the volume is too large, or resistance to air passing through filter media 34 or 134 is too large, excessive amounts of exhaled air may be retained within respective filter body 14 and 114 at normal breathing rates. Also, excessive resistance to air passing through filter media 34 or 134 may quickly result in exhaustion of wearer 12 while performing only normal, routine working procedures. By properly selecting the flow rate of positive low pressure air supplied to filter body 14 and 114 or the flow rate of air removed from filter body 14 and 114 by a source of vacuum along with selecting filter media 34 and 134 with the desired breathability and adjusting the size of respective filter body 14 and 114 accordingly, excessive heating of air within filter body 14 and 114 may be minimized and difficulty with exhaling or inhaling by wearer 12 substantially reduced or eliminated. As a result, face masks 10 and 100 may be satisfactorily worn for extended periods of time without dizziness from rebreathing exhaled air or exhaustion of wearer 12 from difficulty with normal breathing.

Strips of gasket-type sealing material (not expressly shown) or a suitable adhesive such as hydrogel (not expressly shown) may be placed on the portion of top edge 24 and bottom edge 28 adjacent to the face of wearer 12 or the portion of top edge 124, bottom edge 126 and lateral edges 106 and 108 adjacent to the face of wearer 12 to further enhance the fluid tight seal with such adjacent portions of wearer 12 ' s face. Other types of thin film and deformable materials may also be satisfactorily disposed on the periphery of face masks 10 and 100. The flow of air between the periphery of face masks 10 and 100 and adjacent portions of the face of wearer 12 associated with normal breathing of wearer 12 (sometimes referred to as "blow-by") may be substantially eliminated by properly selecting the dimension and location of respective malleable strips 26 and 128 and placing gasket-type sealing material and/or adhesive material on the periphery of face masks 10 and 100 adjacent to the face of wearer 12. For some applications, face masks 10 and 100 may be satisfactorily used without flexible hose 64 by simply placing a cap (not expressly shown) over the portion of connectors 50 and 150 extending from respective filter bodies 14 and 114. For other applications, filter bodies 14 and 114 may be fabricated from materials having a substantially greater basis weight as compared to materials previously used to fabricate respective filter bodies 14 and 114. Also, cooperation between connectors 50 or 150, flexible hose 64 and vacuum source 70, or portable source 170, allows fabricating filter bodies 14 and 114 from multiple layers of filter media 34 and 134 that would have previously resulted in respective face masks 10 and 100, having undesired breathability except for the use of connectors 50 or 150, flexible hose 64 and vacuum source 70 or portable source 170. Similar benefits also result from attaching flexible hose 64 to a source of positive low pressure air.

For still other applications, one or more layers of barrier material such as layer 136 of filter body 114 which are gas permeable and permit gas or air to pass through the respective filter bodies 14 and 114 in both directions and are impermeable to liquids passing respectively through face masks 10 and 100 in at least one direction, may also be included.

A more complete description of the construction arv_ operation of such barrier materials can be found in U.S. Patent 3,929,135 entitled Absorptive Structure Having Tapered Capillaries, issued on December 30, 1975 to ¥.^< ..r. A. Thompson. Such materials are often constructed frcr polyethylene and include small apertures which prevent liquids from passing therethrough due to the liquid's relatively high surface tension. U.S. Patents '960; ' and 5,150,703 entitled Liquid Shi eld Vi sor for a Surg . Mask wi th a Bot tom Notch to Reduce Glare, issued on September 29, 1992 to Hubbard, et al provide additional information on materials which may be used for layers 30, 32, 34 or an additional barrier layer. These patents are incorporated by reference for all purposes within this application. Other types of microporous film may be satisfactorily used with the present invention.

The use of barrier materials such as layer 136 may be particularly important when masks 10 or 100 are worn in an environment where wearer 12 may be exposed to "body fluids." These fluids such as blood, urine and saliva may contain highly contagious germs and viruses. Contact, of AIDS-contaminated body fluids with another person's source of body fluids, such as the eyes, nose and mouth, may transmit the disease. Therefore, it is often preferable to include one or more barrier layers which are resistant to the passage of liquids through filter bodies 14 or 114 to prevent body fluids from contacting the nose and mouth of wearer 12. Still another embodiment of the present invention may include forming one or more layers of filter bodies 14 and/or 114 from an expanded polytetrafluoroethylene (PTFE) membrane. Such materials are manufactured by W. L. Gore & Associates. A more complete description of the construction and operation of such materials can be found in U.S. Patent 3,953,566 entitled Process for Producing Porous Products, issued on April 27, 1976 to Robert W. Gore, and U.S. Patent 4,187,390 entitled Porous Products and Process Therefor, issued on February 5, 1980 to Robert W. Gore. These patents are incorporated by reference for all purposes within this application. The present invention significantly increases the types of material which may be satisfactorily used in fabricating filter bodies 14 and 114. The present invention also allows more options with respect to selecting the number of layers of material used in fabricating each filter body 14 and 114. Non-wetting materials, such as used to form barrier layer 136 typically, have small apertures which prevent liquids with a relatively high surface tension from passing therethrough yet will allow gases with a low surface tension to pass therethrough. It is preferable to have the apertures as large as possible to allow easy breathing, and yet small enough to retard or prevent the flow of liquids. Barrier layer 136 is designed to freely pass gases in either direction, while restricting the passage of liquids in at least one direction. Filtration media 34 and 134 are provided to inhibit the passage of airborne bacteria in either direction which will prevent passage of germs to and from wearer 12. Outer layers 30 and 130 provide the respective external surface for filter bodies 14 and 114, which may be treated, for example, by spraying with a liquid repellant to render the respective external surface material resistant to liquids.

Various types of securing means may be used to attach face masks 10 and 100 incorporating teachings of the present invention to the face of wearer 12.

Headbands 16 and 18 shown in FIGURES 1 represent one of these alternative securing means. Also, elastic ear loops, such as shown in U.S. Patent 4,802,473 entitled Face Mask wi th Ear Loops, may be satisfactorily used with the present invention. U.S. Patent 4,802,473 is incorporated by reference for all purposes within this application. Surgical ties 116 and 118 as shown in FIGURE 4 may be replaced by a continuous loop of resilient material which is disposed within but not bonded to flaps 102 and 104. Surgical ties 116 and 118 may be formed from various types of material.

The arrangement of surgical ties 116 and 118 is such that positioning surgical ties 116 and 118 as shewn in FIGURE 4 results in compressing and gathering the respective flaps 102 and 104 to form a flat, flange type fluid barrier with the face of wearer 12. Surgical ties 116 and 118 may be positioned on the head of wearer 12 to provide the optimum full angle and the optimum amount of force to form the desired fluid barrier between the periphery of mask 100 and the face of wearer 12.

By providing resilient surgical ties 116 and 118, the periphery of face mask 100 will maintain a tight fluid barrier with the face of wearer 12 over a relatively long period of time. Talking and other activities by wearer 12 will not compromise the integrity of the resulting fluid barrier.

For some applications securing means 16 and 18, or 116 and 118, are preferably constructed from resilient polyurethane, but may be constructed from elastic rubber or a covered stretch yarn. The covered stretch yarn may consist of an elastomeric material wrapped with nylon or a polyester. For other applications securing means 16 and 18 or 116 and 118 may comprise double knitted headbands such as circle knitted polyester/LYCRA or nylon/LYCRA. The use of resilient securing means 16, 18, 116 and 118 substantially improves the fluid barrier between the respective periphery of masks 10 and 100 with the face of wearer 12. In addition to the previously discussed materials, face masks 10 and 100 may be manufactured using a wide variety of non-woven materials and/or microporous films. Teachings of the present invention allow incorporating new, state of the art materials as developed into face masks 10 and 100 even though such materials may not have adequate breathability for use in conventional face masks .

Although the present invention has been described in detail with respect to alternative embodiments, various changes and modifications may be suggested to one skilled in the art, and it should be understood that various changes, substitutions, and alterations can be made hereto without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

WHAT IS CLAIMED IS:

1. A disposable face mask comprising: a filter body for covering the nose and .mouth of a wearer, the filter body having a top edge arranged to extend across the nose of the wearer and a bottom edge to extend under the chin of the wearer; the filter body having an interior next to the wearer's face and an exterior exposed to the environment opposite from the interior; the top edge and the bottom edge cooperating with each other to define in part at least portions of the periphery of the face mask which contacts adjacent portions of the face of the wearer; securing means for urging the periphery of the face mask into substantially fluid tight engagement with the adjacent portions of the wearer's face to prevent undesired fluid flow between the periphery of the face mask and the adjacent portions of the face of the wearer; a connector extending through the filter body for coupling the face mask with a flexible hose; and the connector having a longitudinal bore extending therethrough for communicating air between the. exterior and the interior of the filter body.

2. The face mask of Claim 1 further comprising: the flexible hose having one end coupled with a portion of the connector extending from the filter body; and the flexible hose having one end coupled with the extending portion of the connector.

3. The face mask of Claim 2 further comprising flexible hose having another end attached to a source vacuum.

4. The face mask of Claim 2 further comprising the flexible hose having another end attached to a source of positive low pressure air.

5. The face mask of Claim 2 further comprising the flexible hose having another end attached to a portable source of vacuum.

6. The face mask of Claim 2 further comprising the flexible hose having another end attached to a portable source of positive low pressure air.

7. The face mask of Claim 2 further comprising a portable source of both positive low pressure air and a source of vacuum for attachment with the other end of the flexible hose.

8. The face mask of Claim 1 wherein the filter body further comprises: an upper portion having a generally trapezoidal configuration with a longer side forming the top edge; a lower portion having a generally trapezoidal configuration with a longer side forming the bottom edge; the upper portion and the lower portion being joined together along the remaining edges extending from the top edge and the bottom edge; and the connector attached with and extending through the lower portion of the filter body for coupling one end of the flexible hose to the face mask.

9. The face mask of Claim 1 wherein the filter body further comprises: a first lateral edge extending from one end of the top edge to one end of the bottom edge and a second lateral edge extending between a second end of the top edge and a second end of the bottom edge to define in part a generally rectangular configuration; the periphery of the face mask defined in part by the top edge, the bottom edge, the first lateral edge and the second lateral edge; a first flap attached to and extending from the first lateral edge of the filter body; a second flap attached to and extending from the second lateral edge of the filter body; the securing means attached to respective flaps and arranged to extend generally about the head of the wearer to form a substantially fluid tight seal between the periphery of the face mask and portions of the wearer's face adjacent thereto; and the connector attached to a lower portion of the filter body with a portion of the connector extending therefrom for coupling one end of the flexible hose to the face mask.

10. The face mask of Claim 1 further comprising a removable cap placed on a portion of the connector extending through the filter body when the flexible hose is not coupled thereto.

11. A disposable face mask having a periphery which forms a substantially fluid tight seal with adjacent portions of a wearer's face, comprising: a filter body for covering the nose and mouth of a wearer, the filter body having a top edge arranged to extend across the nose of the wearer and a bottom edge arranged to extend under the chin of the wearer; the filter body having an interior next to the wearer's face and an exterior exposed to the environment opposite from the interior; the top edge and the bottom edge cooperating with each other to define in part at least portions of the periphery of the face mask which contacts adjacent portions of the face of the wearer; securing means for urging the periphery of the face mask to form the substantially fluid tight seal with the adjacent portions of the wearer's face to prevent undesired fluid flow between the periphery of the face mask and the adjacent portions of the face of the wearer; a connector extending through the filter body for use in coupling the face mask with one end of a flexible hose; and the connector having a longitudinal bore extending therethrough for communicating air between the exterior and the interior of the filter body.

12. The face mask of Claim 11 further comprising the flexible hose having another end which may be attached to the group consisting of a fixed source of vacuum, a fixed source of positive low pressure air, a portable source of vacuum, or a portable source of positive low pressure air.

13. The face mask of Claim 11 wherein the filter body further comprises: an upper portion having a generally trapezoidal configuration with a longer side forming the top edge; a lower portion having a generally trapezoidal configuration with a longer side forming the bottom edge; the upper portion and the lower portion being joined together along the remaining edges extending from the top edge and the bottom edge; and the connector attached with and extending through the lower portion of the filter body.

14. The face mask of Claim 11 wherein the filter body further comprises: a first lateral edge extending from one end of the top edge to one end of the bottom edge and a second lateral edge extending between a second end of the top edge and a second end of the bottom edge to define in part a generally rectangular configuration; a first flap attached to and extending from the first lateral edge of the filter body; a second flap attached to and extending from the second lateral edge of the filter body; the securing means attached to respective flaps and arranged to extend generally about the head of the wearer to form a substantially fluid tight seal between the periphery of the face mask defined in part by the top edge, the bottom edge, the first lateral edge and the second lateral edge and portions of the wearer's face adjacent thereto; and the connector attached to a lower portion of the filter body with a portion of the connector extending therefrom for coupling the one end of the flexible hose to the face mask.

15. The face mask of Claim 11 further comprising a portable source of both positive low pressure air and a source of vacuum for attachment respectively with anotr.- - end of the flexible hose.