WO2004030764A2

WO2004030764A2 - Contamination avoidance garment

Info

Publication number: WO2004030764A2
Application number: PCT/US2003/014551
Authority: WO
Inventors: Todd R. Carrol; John D. Langley; T. Vencill. Charles; Kathy N. Greene
Original assignee: Kappler, Inc.
Priority date: 2002-05-10
Filing date: 2003-05-08
Publication date: 2004-04-15
Also published as: EP1506042A2; WO2004030764A3; US20040006815A1; AU2003295313A1

Abstract

A contamination avoidance garment for emergency egress during nuclear, biological, and chemical (NBC) events is described. The garment is comprised of a single item, or of multiple garment pieces, and is configured so as to afford the wearer a high degree of barrier to a toxic environment while evacuating to a toxic free area. The garment is designed for easy donning and doffing, and combines the performance characteristics of both continuous film-based barrier composites and toxic vapor absorbing fabrics. The garment is configured to reduce the influx of toxic chemicals by preferentially controlling pressure differentials within the garment by filtering the air entering various garment openings such as sleeves-ends, neck openings, front opening, leg-openings, and/or specifically designed environmental filtration panels.

Description

CONTAMINATION AVOIDANCE GARMENT

FIELD OF THE INVENTION

This invention relates generally to chemical protective clothing and more specifically to a contamination avoidance garment for use during nuclear, biological, and chemical (NBC) events to allow for emergency egress.

BACKGROUND OF THE INVENTION

Millions of chemical protective garments are used each year to protect workers from a specific hazard, or to protect the work environment from the worker. Applications include general maintenance activities, automotive paint spray and finishing, pesticide application, chemical processing and manufacturing, hazardous waste handling, treatment, and disposal, emergency response, hospitals and EMS, pharmaceutical manufacturing and clean room applications, military situations, and innumerable other scenarios. The complexity of exposure scenarios combined with the manufacturing limitations of available polymer and rubber technologies has forced end-users to integrate various personal protective equipment components into an ensemble that together offers the necessary level of protection to ensure the health and well being of the wearer.

Traditionally, protective clothing has been worn by workers who either themselves present a risk to the work area (i.e., medical and clean room applications), or who may be exposed to hazardous environments during the normal course of their work activities (i.e., chemical processing and hazmat). The increased threat of international and domestic terrorism has expanded the need for protective clothing beyond traditional boundaries, and for individuals and workplaces that in the past had no need for such specialized equipment. This threat now includes non-traditional targets that can hold large numbers of civilian personnel such as airports, professional sports stadiums, large office complexes and buildings, government facilities, and non-combative military and quasi- military installations. The protective needs of this vast and dynamic group of individuals is very different than what would be considered traditional users. An effective emergency egress garment needs to offer the user the maximum level of possible comfort, be easily donned/doffed, sized so as to accommodate a wide array of anthropomorphic measurements (i.e., body sizes), require a simple training program, exhibit extended shelf-life, and offer broad protection to a wide range of chemical, nuclear, and biological hazards. While attempts have been made to adapt traditional chemical protective garments, to date, no protective garment has been designed to accommodate the unique and diverse needs of the emergency egress market. In fact, even the industrial protective clothing market is void of performance based standards for evaluating the effectiveness of the vast majority of clothing currently worn by industry.

The U.S. Environmental Protection agency (USEPA), through their Standard Operating Guidelines, have put forth a generic strategy for defining what they term "Levels of Protection" (LOPs). These LOPs revolve around generic types of respiratory protection, as defined by the Occupational Safety and Health Department (OSHA) and the National Institute for Occupational Safety and Health (NIOSH), and genetically described chemical protective clothing, recommended for certain chemical handling activities. The protective clothing industry has and continues to use these guidelines to generically describe the types of garments to be used under various use scenarios. Level "A" is defined as the highest level of respiratory and chemical protection incorporating supplied air (i.e., SCBA or airline respirator) and a fully encapsulating, gas-tight suit. Level "A" ensembles offer the wearer protection against both liquids and vapors. The interface between the glove and sleeve is gas- and liquid-tight, typically consisting of a circular plastic or metal glove-ring that is used as a form around which the glove and sleeve are fitted and then secured with a worm-drive or stepless ear hose-clamp. Level "A" type garments are used by highly trained individuals in situations involving unknown chemicals and a variety of other exposure scenarios involving high exposure potential and carcinogenic hazards. These readily available garments vary in price from ~$500-~$3500, and are available from a variety of manufacturers such as DuPont (USA), Lakeland Industries (USA), Trelleborg (Sweden), Respirex (United Kingdom), Auer (Germany), Draeger (Germany) as well as others. Base fabrics of construction include both lightweight high-chemical barrier composites such as Responder® (DuPont) and TyChem® 10,000 (DuPont), to heavier- weight elastomers such as Viton® and Chlorobutyl from Trelleborg. While offering the highest level of protection to the wearer from both the design/configuration and fabrics of construction, Level A garments are expensive, difficult to don/doff, require a annual inspection program, consume a fairly large volume for the purposes of storage, and require respirator fit testing and medical clearance on the part of the wearer prior to use. These and additional issues make Level "A" garments impractical for use on a large-scale as an escape garment for the average civilian population.

The next lower level of protection described by EPA is Level "B", which is described as requiring the same respiratory protection as Level "A" but with a lesser degree of chemical protection, typically not fully-encapsulating. A traditional Level "B" ensemble includes a self-contained breathing apparatus (i.e., SCBA), a sealed-seam, limited-use coverall with an attached hood, storm-flap, and attached booties, and separate chemically resistant gloves and elastomeric over- boots. It has become common practice to use duct-tape over the glove-sleeve and boot-leg interfaces to minimize penetration of chemicals onto the wearer's skin and clothing. Level "B" type garments are available from a wide variety of manufactures fabricated from an even wider array of base materials, both film- based and elastomeric.

One of the greatest problems with traditional Level "B" garments, when considered for use as emergency egress garments, is an air exchange phenomenon termed "pumping". Since the majority of Level "B" type garments are constructed of non-air permeable, barrier-type fabrics, air will have a tendency to "pump" in and out of the garment through closures (i.e., zippers) and around wrists and ankles during normal and sudden changes in the body position of the wearer such as during kneeling, squatting, and walking. If worn in a contaminated environment, which would be the expected use during emergency egress during an NBC event, contaminated air could be pulled into the garment via this "pumping" action, exposing the wearer. While duct-tape has been used in the past on Level "B" garments as a method of reducing the influx of chemicals through zippers, around wrists, and around ankles, it is impractical to require an average civilian to don a protective garment and "tape-up" during an actual NBC emergency. The psychological stress imposed on a civilian during times of an NBC event will be overbearing which will require an effective protective garment to be easy to don/doff, comfortable, inexpensive, require little initial and sustenance training, be effectively sized so as to accommodate the wide array of wears, as well as be easy to maintain. Requiring a civilian wearer to don a protective garment prior to evacuation during an NBC emergency is difficult enough. Requiring them to tape- up that garment imposes a higher degree of stress and complexity that can be obviated to a great extent by the present invention. Also, since Level "B" still requires the use of supplied air, OSHA and NIOSH require pre-use respirator training and medical qualification.

EPA's Level "C", describes a lesser level of protection than Level B, and includes a lower degree of respiratory protection (i.e., air-purifying respirators), however with similar clothing requirements as in Level "B". Since the chemical hazards and exposures scenarios requiring Level "C" protection are less hazardous than Level "B", "taping" is less common but still used. Level "C" type garments are available in a variety of configurations both one piece and multiple piece, fabricated using a variety of protective fabrics, and incorporating several types of seams, which all affect the ultimate protection afforded the wearer. Unlike Level "B" garments, which are most often constructed using a sealed seam, Level "C", garments are offered with sealed, bounded, and simple sewn seams. Any non- sealed seam, by construction, has the potential for allowing influx of hazardous chemicals, thus exposing the wearer. While Level "C" type clothing requires air-purifying respiratory equipment, which also requires the same basic type of testing and medical qualification as supplied air, these type garments could be used with what OSHA and NIOSH consider "emergency" respirators which do not require pre-use medical clearance. Obviously "pumping" is also a major limiting factor with traditional Level "C" garments.

Level "D" protection is the lowest level of protection described by EPA and is used in situations where there is no risk of respiratory exposure and very limited potential for exposure to low hazard chemicals. Chemical protective clothing is allowable under Level "D", however, rarely worn. Applicability of Level "D" equipment is obviously outside the scope of the expected exposure scenario of an emergency egress garment. It should be evident from the above discussion, that an immediate need exists for a garment designed specifically for emergency egress. The present invention addresses many of the limitations of existing protective strategies as well as the related prior art.

An effective chemical protective ensemble can only be designed on the basis of a detailed hazard assessment. Similarly, selection of the most appropriate chemical protective garment on the end-user level relies on similar information. In fact, the United States Occupational Safety and Health Administration (OSHA), requires that a documented hazard assessment be conducted within the workplace to support the selection and use of any chemical protective clothing (i.e., 29 C.F.R. 1910.132). This analysis takes into account the expected chemical hazard(s) involved in the situation, the probability of exposure, and the expected exposure scenario (i.e., duration and degree). Taking this information into account, the manufacturer can then select the appropriate materials of construction which include fabrics and seam type, and in turn, construct a garment that is configured such as to afford the wearer the necessary level of protection for the expected use scenario. Relatively controlled situations such as inspection operations on chemical lines in a petrochemical facility will obviously require a different type garment (i.e., fabrics, seams, and configuration) than for an emergency responder whose scenario will be different during each spill. Likewise, the specific needs for an emergency egress garment must be anticipated based on a similar hazard assessment. Two basic technological approaches have been employed in designing the primary materials used in the construction of chemical protective clothing (i.e., "barrier" and "adsorption"). The majority of clothing used by general industry is based on "barrier" technology. Barrier technology hinges on the principle that the protective material essentially blocks the transport of a chemical through the material. The chemical resistance of "barrier" type materials is dictated by Fick's Law of Diffusion, and the solubility of the chemical hazard(s) in the polymer matrix of the protective material. The industry standard used for evaluating chemical resistance is the American Society for Testing and Materials (ASTM) F739 - Standard Test Method for Resistance of Protective Clothing Materials to Permeation by Liquids and Gases. This method is applicable to essentially any chemical and all chemical forms (i.e., solids, liquids, and gases). Numerous attempts have been made to develop chemical protective fabrics that offer a wide range of chemical resistance including Bartasis (U.S. Pat. No. 4,920,575), Blackburn (U.S. Pat. No. 5,035,941), Hauer et al. (U.S. Pat. No. 5,626,947), Hendriksen (U.S. Pat. No. 5,059,477), Langley (U.S. Pat. Nos. 4,833,010 and 4,855,178), Sahatjian et al. (U.S. Pat. No. 4,943,473), Shah (U.S. Pat. No. 4,755,419), van Gompel (U.S. Pat. No. 4,753,419), as well as many others. Each of the above mentioned approaches incorporate various types of continuous chemical barriers, and strength enhancing substrates, scrims, and reinforcing base fabrics to achieve the desired level of chemical resistance and physical durability. These and other "barrier" approaches have been reduced to practice and today make up what is termed the limited-use chemical protective clothing market. These lightweight, cost effective garments offer a variety of advantages including ease of hermetic heat-sealability. Garments costing the end user under $75 have proven effective against a wide range of chemical challenges.

While the "barrier" approach can result in a high degree of chemical resistance, it comes at the expense of wearer comfort. "Barrier" type fabrics resist the transport of chemicals into the garment, and as a result, prevent the transmission of any moisture out from the garment that is generated by the wearer. Eliminating the body's natural thermal regulating system, evaporative cooling, can result in rapid and serious physiological stress. Restricting or eliminating the potential for sweat evaporation will result in varying degrees of heat stress related illness. Practically speaking, garments categorized as Level "B" and above are typically designed as complete barriers to moisture transfer to ensure adequate protection from the expected chemical exposure scenario. As mentioned previously, "pumping" is an inherent phenomenon that occurs while wearing garments fabricated from "barrier" type materials, and in turn is one of the most limiting characteristics of using such an approach for an emergency egress garment. "Pumping" occurs at garment openings such as front closures, around the sleeves, and boot openings, as well as at the nap of the neck, even if the zipper closure is fully engaged. De Guzman (U.S. Pat. No. 6,122,772), and Jones et al. (U.S. Pat. No. 4,932,078) describe this "pumping" phenomenon in relation to the design of an effective clean room garment. The United States Army, through the Soldier Biological Chemical Command (SBCCOM), have quantified this "pumping" action on various garments using the Man-In-Simulant Test (M.I.S.T.), which is routinely used to evaluate the effectiveness of military battle ground garments, and most recently is being used to evaluate the performance of commercially available chemical protective clothing in support of the domestic preparedness objective. Testing has demonstrated that the highest concentration of chemical contamination occurs, as expected, in the and around the closures including the front opening, wrist, and ankles.

In contrast to the "barrier" approach of blocking chemical transport, an alternative approach, used extensively within the military, is termed "adsorption". "Adsorption" technology for chemical protection as the term implies, is based on the selective adsorption of toxic chemicals by one or more components present within the protective fabric. Adsorption can result via physisorption or chemisorption. This filtration-type approach is advantageous when applied to protective clothing, in that the fabrics offer a defined level of chemical resistance while maintaining a relatively high degree of comfort. "Adsorption" based materials and resulting garments, are significantly more expensive than "barrier" type materials which limit their applicability for widespread use as an emergency egress garment. Additionally, since adsorption is a vapor-based phenomenon, use of these type garments is typically limited to airborne challenges. A significant amount of established art exists in the field of adsorptive materials, especially in the areas of protective clothing and filtration/respiratory materials. One of the most widely used examples of this technology incorporates activated charcoal that is adhered to traditional textile materials as described by von Blucher et al. (U.S. Pat. Nos. 4,510,193, 4,677,019, and 5,277,963). Used as the primary protective material in the U.S. military battle dress over-garment (MIL-C-29462), this technology has been shown to be effective for its designed purpose. Numerous other attempts have been made to incorporate "adsorption" into various protective formats. Collier et al. (U. S. Pat. No. 5,453,314), Farnworth et al. (U.S. Pat. Nos. 4,981,738 & 5,017,424), Hart et al. (U.S. Pat. No. 4,190,696), Haruvey et al. (U.S. Pat . No. 4,872,220), Katz (U.S. Pat. Nos. 5,162,398 & 5,614,301), Langston (U.S. Pat. No. 5,112,666), Meunier (U.S. Pat. No. 5,221,572), Stelzmuller et al. (5,731,065), Vickers (U.S. Pat. No. 5,678,247), etc., have used activated charcoal, or other adsorptive media, such as silicylic acid, xerogels, xeolites, metal oxides and hydroxides (i.e., hydrated alumina silicate), molecular sieves, exchange resins, etc., to induce intrinsic chemical adsorption characteristics to a fabric. Sorptive performance has been engineered into various traditional and non-traditional woven and non-woven fabrics and composites, foams, and fibers, which have been further converted into various items of protective clothing. Additional attempts have been made to induce other performance characteristics to adsorptive fabrics such as stretch and recovery, flame resistance, and even detoxification characteristics through the use of surface modifying enzymes (von Blucher et al. U.S. Pat. No. '193). The beauty of sorptive technology, and especially activated charcoal, is its flexibility, through specialized surface treatments, to increase and expand the chemical adsorptive properties. Several disadvantages of traditional sorptive fabrics as described by Langston (U.S. Pat. No. '666) and others, include, balancing the level of sorptive loading while maximizing air flow and resulting comfort, degradation of the charcoal due to aging of the bonding process, shedding of charcoal through abrasion and during conversion and normal wearing, and over loading of the sorptive capacity by nonspecific chemicals and/or high vapor and liquid challenges. Another disadvantage of adsorptive fabrics, especially activated charcoal, is its sensitive long-term storage requirements. The intrinsic moisture sensitivity of activated charcoal requires that items be sealed during storage. Since the use of the garment of the present invention would be unexpected, garments will most likely sit "on-the- shelf ' for extended periods of time prior to use. There is no way to readily evaluate the level of "activity" or retained adsorption capacity of a wholly

"adsorptive" garment prior to donning. Extended storage for film-based, "barrier" fabrics is typically not an issue.

Yet another disadvantage of "adsorptive" fabrics, when used in emergency egress garments, are their limitation to primarily vapor challenges, which includes water (i.e., rain). The most common approach to improving the liquid resistance of sorptive fabrics, is through the use of surface repellency treatments such as Scotchgard® and Zepel-B®. While surface treatments improve the liquid repellency (i.e., run-off) of the fabric, they are easily overwhelmed during heavy exposures and rain events, and cannot prevent liquid penetration while the fabric is under physical pressure such as would occur during crawling, or that might occur in the crutch of the arm while in movement which would physically force the chemical through the fabric. Limitations also exist with respect to the resistance of adsorptive fabrics to particulate challenges such as biological hazards (i.e., anthrax). Resistance to particulate hazards is based on a physical barrier rather than a sorptive mode. Increases in the particulate resistance characteristics of a sorptive material will be inversely related to comfort.

Due to the intrinsic air-permeability of "adsorptive" fabrics, the "pumping" phenomenon that occurs with garments constructed using only "barrier" materials is still present, however, to a lesser degree. Since air can move through the base fabric, a lower pressure differential exists within the garment which translates to less "unfiltered" air being pulled into the garment openings such as sleeves, neck, front closure, etc.

The advantages of "barrier" type fabrics are low cost, high and broad chemical resistance, ease of heat sealability, and extended shelf life. Their greatest disadvantage is air/vapor impermeability which results in "pumping", which has the potential of exposing the wearer to contaminated air being drawn from outside the garment through openings such as front closures, seams, sleeves, neck openings, etc. The advantages of "adsorptive" fabrics are, definable chemical resistance to vapors, and air permeability. The greatest disadvantage of "adsorptive" fabrics is their applicability to primarily vapor challenges. The present invention presents a novel approach to utilizing the advantageous performance characteristics of both these protective strategies while minimizing their aforedescribed limitations. This synergistic use of two opposing performance characteristics manifests itself in a protective strategy that is uniquely apposite for the complex needs of an emergency egress garment.

It will be seen from the above teaching, that the need exists for an effectively designed emergency egress garment that offers the user easy don- and doff ability, is lightweight, comfortable, exhibits extended shelf-life, and is so designed and configured to offer a wide range of resistance to various types of solid, liquid and vapor challenges as would exist during terrorist events.

SUMMARY OF THE INVENTION

The present invention provides for a simple and novel protective strategy for contamination avoidance garments that offers adequate protection and stress relief that cannot be achieved by prior disclosed methods, materials, concepts, or technologies. The garment is constructed primarily of barrier type chemical fabrics and is configured so as to cover at least the wearer's arms, legs, and torso. The garment is constructed such that all air that might move from outside the garment in, or conversely inside the garment out, must first pass through a sorptive interface. In one embodiment, the garment comprises a barrier fabric that resists permeation by liquid and vapor based military chemical agents and toxic industrial chemicals, the garment containing an air filtration mechanism based on sorptive materials fitted so as to filter air that enters and exits the garment during use. hi a specific embodiment, the garment of the present invention has sleeve portions, leg portions and a torso portion fabricated from an impermeable barrier fabric. The garment also has at least one portion fabricated from a permeable fabric that is chemically adsorptive and is fitted so as to filter air that enters and exits the garment during use. hi certain embodiments, the garment has tubular sleeve inserts fabricated from said adsorptive air permeable fabric and located within the sleeve portions of the garment. The garment may also have tubular leg inserts fabricated from said adsorptive air permeable fabric and located within the leg portions of the garment.

This invention is applicable to a wide variety of barrier fabrics. As used herein, a "barrier" fabric is a material that provides resistance to chemicals of interest, such as military chemical warfare agents and toxic industrial chemicals, but provides no measurable air permeability. The barrier fabric can be totally impermeable to all materials, or can be made of a perm-selective material that is a barrier to chemical agents of interest but is selectively permeable to other materials, such as water vapor, thus enhancing comfort for the wearer. Barrier fabrics can also be made of certain monolithic breathable films or membranes, such as Hytrel®, or can be made of microporous breathable films or membranes, such as Gore-Tex®.

According to the present invention, major portions of the garment are made from a barrier fabric, and air permeable "adsorptive" type materials are used in certain selected areas of the garment where air might enter or leave the garment. Ideally, the garment will be either one-piece or multiple pieces of separable garment items to achieve the desired level of protection. While several embodiments will be described, a one-piece coverall-type design is preferred for ease and speed of donning during an emergency egress event. The desired garment is constructed primarily of a highly chemically resistant "barrier" material such as Zytron® 300 (Kappler, Guntersville, AL)) which is a bi-laminate comprising a coextruded film and a 2.0 oz/yd² spundbonded polypropylene nonwoven web. Alternative chemical protective fabrics that offer resistance to military warfare agents and a wide range of toxic industrial chemicals could also be used.

BRIEF DESCRIPTION OF THE DRAWINGS

Some of the features and advantages of the invention having been described, others will become apparent from the detailed description which follows, and from the accompanying drawings, in which ~ FIG. 1 is a full front view of a garment in accordance with the present invention in the form of a coverall.

FIG. 2 is a fragmentary front view of the garment of Figure 1, showing the triple storm-flap zippered closure. FIG. 3 is a front view of a jacket in accordance with another embodiment of the present invention.

FIGS. 4 and 5 illustrate further embodiments of multiple piece garments in accordance with the present invention, these being bib overalls (FIG. 4) and pants (FIG. 5). FIG. 6 is a front view of another embodiment of garment in accordance with the present invention; and

FIGS. 6 A, 6B and 6C are detailed views showing several options for flexible two-way environmental air management mechanisms that can be fitted to an emergency egress garment such as that shown in FIG. 6.

DESCRIPTION OF ILLUSTRATED EMBODIMENTS

The present inventions now will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the invention are shown. Indeed, these inventions may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like numbers refer to like elements throughout. The embodiment shown in FIG. 1 is a standard style coverall including a zippered front opening, and incorporates both "barrier" and "sorptive" fabrics. The one-piece, garment 10 is preferably supplied to the user in a hermetically sealed package (not shown) which is kept sealed until ready for use in order that the garment will have extended shelf life. The one-piece coverall garment 10 is fabricated primarily from a "barrier" type fabric 11 such as Zytron® 300, from Kappler, Guntersville, AL. The distal sleeve and leg openings 12, 15 can be finished with a simple hem or may be provided with a constrictable opening using elastic or a drawstring or other suitable methods. The sleeve and leg openings can be further modified with the addition of a repositionable strap 14, 17 which can further improve the overall filtration efficiency at these openings. Adsorptive sleeve, leg, and neck collar inserts are shown respectively as 13, 16, 18, and 19. The triple storm flap 20 is further described in connection with FIG. 2. All seams on the garment are sewn and hermetically sealed on the outside of the garment using seam tape as described by Langley et al. (U.S. Pat. No. 5,169,697). Hermetic seams are preferred to maximize the chemical resistance of the final garment, thus preventing influx of chemical agents through holes created during the garment assembly and sewing process. While other embodiments could be conceived with attached hoods or other head covering design features, the design shown in FIG. 1 will allow integration to most known and anticipated respiratory devices, which would be required to be worn in addition to the emergency egress garment, described in this application.

Sorptive interface material is used in and around all areas that would otherwise allow infiltration of potentially contaminated air into the garment as a result of the "pumping" phenomenon described previously. The sorptive material may comprise a woven, nonwoven, fibrous, or foamed fabric having sorptive agents incorporated therein. The sorptive function of the agent can be based on either physisorption or chemisorption. Examples of sorptive agents that can be used include one or more adsorptive media selected from the group consisting of activated carbon, activated carbon fibers, zeolites, bituminous earth, porous polymers, hydrated alumina silicate, sepiolites, silica gel, alumina, magnesia, calcium carbonate, chlorophyll, baking soda, soda lime, calcium oxide, and potassium permanganate. The sorptive interface used in the illustrated embodiments was CD2610, available through Gentex Corp., Carbondale, PA. CD2610 is an 8.9-oz/yd² activated charcoal composite that satisfies all of the testing criteria as detailed in the governments JSLIST program as a 30-day overgarment. Alternative examples of adsorptive fabric from different suppliers could also be used. An example of a nonwoven fabric incorporating adsorptive particles is disclosed in United States Patent 5,952,092 and 5,972,808. An adsorptive sleeve insert 13 of CD2610 of dimensions approximately 12- in in length having a circumference of approximately 14-in was fabricated and inserted into the end of each sleeve. The adsorptive sleeve insert was constructed by sewing together a tube of material and finishing both the proximal and distal openings with elastic. The adsorptive insert is attached to the garment by anchoring the proximal opening approximately 8-in up from the distal opening of the coverall sleeve. Attachment is via a radial sew line that is further hermetically sealed on the exterior of the garment to prevent the penetration of any liquid challenge. A critical path of filtration is created according to this design, by the wearer inserting bis or her hand and arm through the insert and outer sleeve, thus extending the adsorptive insert past the distal opening of the garment sleeve. To complete the donning procedure, the wearer retracts the hand slightly such that an accordion affect occurs on the adsorptive insert when the distal elastic of the insert is brought inside the distal end of the garment sleeve. The net effect of the accordion-type bunching and the elastic in the proximal and distal openings of the insert is to create a critical path for air transfer, which in effect, forces any air "pumping" into or out of the garment sleeve to be filtered by the adsorptive insert. The critical path concept can be further improved upon by adding additional elastic to the distal opening of the garment sleeve, or by adding a repositionable Velcro® wrist strap that can be engaged radially around the wrist thus further compressing the adsorptive insert. A similar approach can be used to fabricate leg cuff inserts 16 in the leg openings, however with different dimensions. It should be evident that other designs could be conceived to accomplish the same net effect of filtering air through an adsorptive media placed at the sleeve and leg openings. Two remaining sensitive areas that can contribute to contamination as a result of "pumping" are around the neck and the front opening on a coverall, and around the waist of a jacket, pant, or bib overall. Since emergency egress situations must be anticipated under all conditions, contributory environmental influences must be considered. In the extreme, an evacuation can be anticipated through a liquid challenge and while during a rain event. This combination would result in failure of most wholly sorptive garments, if nowhere else except through the sewn seams. The garments of the present invention present a front closure that, when used in combination with a hermetically sealed seam will pass liquid-tight integrity test (i.e., shower test) as described by ASTM F1358. This test exposes a garment to a deluge of surfactant-treated water via 5 showerheads. The garment is mounted on a mannequin and the mannequin is incrementally rotated through 360°. A reasonable exposure duration for emergency egress purposes is 20 minutes, such as is specified in the National Fire Protection Association (NFPA) NFPA 1992 - Standard on Liquid Splash-Protective Suits for Hazardous Chemical Emergencies. Traditional garments such as the Level B garments described above could not pass the shower test without modification with duct-tape. The garment of the present invention can pass the test since it is fitted with a triple storm-flap which includes a first outer flap, and first inner-flap, a traditional cloth zipper, and a second inner flap/placate that is positioned inside the zipper and in this embodiment, is a double-layer of the CD2610 adsorptive fabric. The first outer and first inner storm-flaps are removably attached via a full length of a hook and pile closure such as Velcro®. This closure will repel any liquid exposure, and has the added benefit of filtering air that is pushed from outside the garment or that might be drawn in through the closure.

The final entry point for contaminated air is through the head opening and around the neck. The present invention improves upon existing approaches by adding an optional circular inner collar insert 18 of adsorptive material. The sorptive neck insert 18 is positioned perpendicular to the neck and is finished on the exposed edge with elastic. The insert extends beyond the end of the collar and onto the second inner storm-flap to ensure that the entire neck is encircled by the sorptive insert. Additional adsorptive material 19 can be placed on the interior of a mandarin-type collar, which will further serve to reduce any vapor threat by scavenging present airborne challenges. Additionally, an inner collar-collar can be added to the insert, preferable fabricated from elasticized sorptive material that would act more like a turtleneck. Additional security can be added by fitting the collar with a repositionable strap such as was described above for use around the wrist and ankles. Similar approaches to the neck closure can be incorporated into the waist of multi-piece garments such as jackets, pants, and bib overalls, as shown in FIGS. 3, 4 and 5.

FIG. 2 shows the triple storm-flap zippered closure that enables passage of ASTM Fl 358. This closure can be used on single and multiple piece garments such as coveralls and jackets. The outer storm-flap 20 is fitted with the loop portion 22 of the repositionable hook and loop fastener. The second outer storm- flap 21 is fitted with the hook portion 23 of the repositionable hook and loop fastener. The cloth zipper 27 is further backed by a double-layer sorptive inner storm-flap 24. The sorptive neck insert that encases the wearer's neck is indicated at 25. An additional layer 26 of sorptive material is provided on the interior of the mandarin collar.

FIG. 3 illustrates a jacket 30 that incorporates either hemming or elastic at the distal sleeve opening 32, or a repositionable strap 34, that can be engaged over the adsorptive sleeve insert 33. A waist insert 35 formed of adsorptive material is provided along the waistband of the jacket extending inwardly to engage the wearer's waist. The waist insert is thus arranged to filter any air that may enter or leave the jacket from the waist area. The waist insert 35 is attached to the jacket waistband along its outer periphery has an inner periphery which is made constiictable, e.g. by an elastic hem, to snugly engage the waist. The jacket has the same configuration of a triple storm-flap 36 and adsorptive neck insert 37 as is disclosed in FIG. 2.

FIGS. 4 and 5 show further embodiments of multiple piece components, these being bib overalls (FIG. 4) and pants (FIG. 5). FIG. 4 discloses a bib overall 40, constructed primarily of the barrier material 41, incorporating either a hem or elastic at the distal leg opening 42. These bib overalls also include an adsorptive leg insert 43 of the type previously described, and a repositionable strap, 44, as well as an adsorptive upper waist insert 45. The waist insert 45 is attached along its outer radius to the barrier fabric 41, such as by sewing, and has a constrictible inner radius formed by elastic, a drawstring or other suitable arrangement.

Similarly, FIG. 5 discloses pants 50 fabricated from a barrier material 51, including a hemmed or elasticized distal leg opening 52, an adsorptive leg insert, 53, and an optional repositionable strap 54. An adsorptive waist insert 56 is positioned close to the primary opening 55 which can incorporate elastic, drawstring, or other closure that is common in the industry.

Since it may be preferred to construct an emergency egress garment with attached boots and gloves, as well as a liquid and/or vapor tight closure, an alternative method for managing "pumping" may be required. The present invention also provides a novel flexible bi-directional air exchange mechanism that effectively releases heat and moisture that may build-up inside the garment, yet filters any incoming air that might be contaminated. This required bi-directional valving cannot be accomplished using traditional uni-directional valves that are common in gas-tight Level A garments. These valves have been borrowed from the air-purifying respiratory market and are typically used behind a filter cartridge. In a respirator, air is brought through the filter cartridge or canister and into the mask for inhalation by the wearer, a flapper valves closes the cartridge passage and exhaled air exists through a second one-way valve. This uni-directional flow is effective for respiratory equipment but inadequate for an emergency egress garment since the present invention attempts to filter air that infiltrates the garment as a result of "pumping". Three such approaches are described herein, however others could be anticipated. The first utilizes a typical valve body that is fitted in the garment, hi place of the one-way flapper valve, multiple rings of adsorptive fabric can be inserted within the valve body thus creating a critical path of adsorptive media through which any air must flow when entering or exiting the garment. Greater filtering efficiency can be achieved using thick layers of sorptive fabric. An exterior exhaust cover fabricated from the "barrier" material is also preferred to shed any liquid that might come in proximity of the exhaust port.

An alternative approach for managing potentially contaminated air flow into a garment is to fit either single or multiple layers of sorptive fabric over an opening in the garment, which has the same net effect as the valve body inserts.

The sorptive material can be attached to the interior of the garment according to several different techniques including adhesives, heat-sealing within a barrier fabric frame/enclosure or other means. Again it is preferred to incorporate single and or double exterior exhaust covers to minimize liquid contact of the sorptive media.

A third approach to creating a flexible bi-directional air exchange mechanism is to provide a fitting in the form, for example of a valve body, that surrounds an opening formed in the barrier fabric. Various configurations of adsorptive inserts can be connected to the fitting or valve body. For example, the valve body can be connected to a secondary air infiltration bag not unlike a disposable vacuum cleaner bag. In this case, a bag is fitted around the interior of the valve body and is either constructed of or contains adsorptive media. The principle here again is to force any air through the sorptive media which in turn offers the wearer a high degree of comfort since heat and perspiration can exit the garment, and contaminated air is filtered through the sorptive inserts.

One final approach for bi-directional airflow management that is especially suited for garments that maybe more encapsulating in design (i.e., those incorporating attached hood, gloves, boots, and liquid- or gas-proof closures), is to modify the operation of traditional unidirectional air-purifying respirator cartridge/canister systems. One or more air-purifying respirator cartridges/canisters can be mounted in the garment without the use of or including the unidirectional flapper valve that is most often removably mounted in the cartridge mounting body. An NBC approved cartridge or canister is best suited for this application. The convention of use will allow free airflow through the cartridge or canister. The present invention can accommodate a variety of "barrier" and "sorptive" fabrics, as well as alternative flexible 2-way air exchange mechanisms. FIG. 6 shows several options for flexible two-way environmental air management mechanisms that can be fitted to an emergency egress garment, 60. FIG. 6A illustrates use of a typical valve body 64 that has been fitted with one or more adsorptive disks 65. The valve body includes a rigid cap 62, which offers physical protection to the adsorptive media, the entire ensemble of which is set in the barrier fabric, 63, and further covered with an additional layer of barrier fabric 61 in the form of a protective flap that acts as a splash-cover. FIG. 6B shows an alternative embodiment that utilizes a layer of the adsorptive materials 69 that has been adhered to the inside the garment and barrier fabric 68, and further covered by overlapping upper and lower protective flaps 66, 67 serving splash-covers. FIG. 6C discloses yet another embodiment that incorporates a valve body 73 that holds an adsorptive bag 74, the valve body of which is covered by a rigid cover 72, and set in the barrier fabric 70. The entire valve system is further covered by the splashguard 71.

The filter efficiency of the bi-directional air management system can be controlled with variable loading levels of the adsorptive component, and/or multiple separate layers, or configurations of the adsorptive fabric. The bi- directional air filtration mechanism is comprised of one or more air purifying type respiratory cartridges or canisters.

Many modifications and other embodiments of the inventions set forth herein will come to mind to one skilled in the art to which these inventions pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the inventions are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

Claims

THAT WHICH IS CLAIMED IS:

1. A contamination avoidance garment comprising a barrier fabric that resists permeation by liquid and vapor based military chemical agents and toxic industrial chemicals, the garment containing a bi-directional air filtration mechanism based on sorptive materials fitted so as to filter air that enters and exits the garment during use.

2. The garment of Claim 1, wherein the barrier fabric includes one or more layers comprised of a thermoplastic resin selected from the group consisting of polyvinyl chloride, chlorinated polyethylene, chlorinated butyl, polyethylene, high density polyethylene, low density polyethylene, linear low density polyethylene, polypropylene, polyurethane, PTFE, combinations thereof, or multiple-layered coextruded films which include one or more layers of ethylene- vinyl acetate, ethylene vinyl alcohol, polyvinyl alcohol, nylon, ionomer, or polyester.

3. The garment of Claim 1, wherein the garment includes a torso portion and limb portions, each defining primary openings in the garment, and wherein said sorptive materials are fitted inside at least one of the primary openings of the garment.

4. The garment of Claim 3, wherein the garment includes sleeves that form primary openings in the garment for the wearer's hands and the sorptive materials are fitted inside these primary openings.

5. The garment of Claim 1, wherein the garment includes a neck opening and the sorptive materials are fitted inside the neck opening of the garment.

6. The garment of Claim 1 , wherein the garment includes sleeves and the bi-directional air filtration mechanism comprises tubular arm cuff inserts formed of adsorptive material, the tubular arm cuff inserts being attached to the interior of the gannent sleeves, and having a constrictable opening for engaging the wearer's wrist.

7. The garment of Claim 1, wherein the garment includes legs and the bi-directional air filtration mechanism also comprises tubular leg cuff inserts formed of adsorptive material, the tubular leg cuff inserts being attached to the interior of the garment legs, and having a constrictable opening for engaging the wearer's ankle.

8. The garment of Claim 1 , wherein the garment includes a primary front closure and the sorptive material is positioned behind the primary front closure of the garment.

9. The garment of Claim 8, wherein a triple storm flap which passes

ASTM F1358 is provided in the garment, the storm flap including a first outer flap and a first inner flap, both of barrier material and located outside the primary front closure of the garment, further including a second inner flap of adsorptive material located inside the closure.

10. The garment of Claim 9, wherein the closure is selected from the group consisting of a hook and loop closure, a zipper, or a zip-lock closure.

11. The garment of Claim 1 , wherein the sorptive material is comprised of a woven, nonwoven, fibrous, or foamed fabric.

12. The garment of Claim 11 , wherein the activity of the sorptive material is based on either physisorption or chemisorption.

13. The garment of Claim 12, wherein the sorptive material comprises one or more adsorptive media selected from the group consisting of activated carbon, activated carbon fibers, zeolites, bituminous earth, porous polymers, hydrated alumina silicate, sepiolites, silica gel, alumina, magnesia, calcium carbonate, chlorophyll, baking soda, soda lime, calcium oxide, and potassium permanganate.

14. The garment of Claim 1 , wherein the bi-directional air filtration mechanism includes a valve body mounted in the barrier fabric and defining a opening therethrough, and at least one layer of adsorptive fabric mounted in the valve body across said opening.

15. The garment of Claim 14, including a cover overlying the outer exposed surface of said valve body.

16. The garment of Claim 1 , wherein the bi-directional air filtration mechanism comprises an opening formed in the barrier fabric, and at least one layer of adsorptive fabric mounted to the barrier fabric and extending across said opening.

17. The garment of Claim 16, including a cover overlying the outer exposed surface the adsorptive fabric.

18. The garment of Claim 1, wherein the bi-directional air filtration mechanism comprises an opening formed in the barrier fabric, and an air-purifying cartridge or canister connected in fluid communication with said opening.

19. The garment of Claim 1, wherein, the bi-directional air filtration system comprises one or more adsorptive media selected from the group consisting of activated carbon, activated carbon fibers, zeolites, bituminous earth, porous polymers, hydrated alumina silicate, sepiolites, silica gel, alumina, magnesia, calcium carbonate, chlorophyll, baking soda, soda lime, calcium oxide, and potassium permanganate.

20. The garment of Claim 19, wherein the bi-directional air filtration system is in the form of a panel fabricated from adsorptive media, said panel being disposed across an opening formed in said barrier fabric.

21. The garment of Claim 20, including a cover overlying an exposed outer surface of said panel.

22. The garment of Claim 19, wherein the bi-directional air filtration system is in the form of one or more adsorptive disks fitted inside a rigid or flexible pressure relief valve body, said valve body being mounted surrounding an opening formed in said barrier fabric.

23. The garment of Claim 19, wherein the bi-directional filtration system is in the form of a vapor adsorbent bag fitted inside the garment.

24. A contamination avoidance garment having sleeve portions, leg portions and a torso portion fabricated from an impermeable barrier fabric, the garment also having at least one portion fabricated from a permeable material that is chemically adsorptive and is fitted so as to filter air that enters and exits the garment during use.

25. The garment of Claim 24 wherein said permeable material is an air permeable flexible fabric material that contains one or more adsorptive media selected from the group consisting of activated carbon, activated carbon fibers, zeolites, bituminous earth, porous polymers, hydrated alumina silicate, sepiolites, silica gel, alumina, magnesia, calcium carbonate, chlorophyll, baking soda, soda lime, calcium oxide, and potassium permanganate.

26. The garment of Claim 25 wherein said at least one portion comprises tubular sleeve inserts fabricated from said adsorptive air permeable fabric and located within the sleeve portions of the garment.

27. The garment of Claim 25 wherein said at least one portion comprises tubular leg inserts fabricated from said adsorptive air permeable fabric and located within the leg portions of the garment.

28. The garment of Claim 25 which includes a neck opening adjacent an upper end of said torso portion, and a neck collar insert fabricated from said adsorptive air permeable fabric mounted adjacent said neck opening.

29. The garment of Claim 25 which includes a primary front closure in the torso portion of the garment, and a triple storm flap which passes ASTM F1358 provided along said closure, the storm flap including a first outer flap and a first inner flap, both of barrier material and located outside the primary front closure of the garment, further including a second inner flap of said adsorptive fabric located inside the closure.

30. The garment of Claim 25 which includes an opening formed in the impermeable barrier fabric, and wherein said chemically adsorptive permeable fabric covers said opening.

31. The garment of Claim 30, additionally including a valve body mounted to the barrier fabric and covering said opening, and wherein said chemically adsorptive permeable fabric is located inside said valve body.

32. The gannent of Claim 30, including a protective flap formed of barrier fabric and positioned adjacent said opening to serve as a splash cover.

33. The garment of Claim 24 which includes an opening formed in the impermeable barrier fabric, and including a fitting mounted to the barrier fabric and covering said opening, and wherein said adsorbent material is positioned so that air entering or leaving the garment through said opening passes through the adsorbent material.

34. The garment of Claim 33, wherein the adsorbent material comprises one or more adsorptive disks fitted inside said fitting.

35. The garment of Claim 33, wherein the adsorbent material comprises an adsorptive bag connected to the fitting.

36. The garment of Claim 33, including a canister connected to said fitting, and wherein the canister contains the adsorbent material.

37. A contamination avoidance gannent, said gannent comprising sleeve portions and a torso portion fabricated from an impermeable barrier fabric, and tubular sleeve inserts fabricated from a chemically adsorptive air permeable fabric located within the sleeve portions of the garment.

38. The garment of Claim 37 wherein the tubular sleeve inserts have one end thereof joined to the interior of the sleeve portion of the garment and an opposite end thereof provided with an elasticized wrist opening.

39. The garment of Claim 37 which includes a waist opening adjacent a lower end of said torso portion, and an inner waistband insert fabricated from a chemically adsorptive air permeable fabric adjoining the waist opening.

40. The garment of Claim 37 which includes a neck opening adjacent an upper end of said torso portion, and an inner neck collar insert fabricated from a chemically adsorptive air permeable fabric adjoining the neck opening.

41. A contamination avoidance garment, said garment comprising leg portions and a torso portion fabricated from an impermeable barrier fabric, and tubular leg inserts fabricated from a chemically adsorptive air permeable fabric located within the leg portions of the garment.

42. The garment of Claim 41 which includes a waist opening adjacent an upper end of said torso portion, and an inner waistband insert fabricated from a chemically adsorptive air permeable fabric adjoining the waist opening.

43. The garment of Claim 42 in the form of bib overalls, including front and rear chest covering portions located above said inner waistband formed of said barrier fabric, and suspenders carried by said chest covering portions.

44. The garment of Claim 42 in the form of trousers.