Personal protective equipment garment

Abstract

The present invention relates to a personal protective equipment (PPE) garment comprising a multilayer sheet comprising at least two layers, comprising at least one breathable monolithic film layer (1) comprising a thermoplastic polymer and having a Moisture Vapor Transmission Rate (MVTR) of at least 500 g / (m2*day) as measured according to ASTM E96 protocol B at 38 °C and 50% relative humidity; and at least one micro-structured porous layer (2) having a basis weight of at least 10 grams per square meter (gsm); wherein each of the layers (1) and (2) has a basis weight of at least 10 grams per square meter (gsm) and all of the layers (1) and (2) have a combined basis weight of at least 30 grams per square meter (gsm).

Description

[0001]PERSONAL PROTECTIVE EQUIPMENT GARMENT INTRODUCTION This invention relates to a personal protective equipment (PPE) garment, as well as a method to prepare the PPE garment. More particular, the invention relates to a personal protective equipment (PPE) garment comprising a multilayer sheet, which is suitable for use in applications such a chemotherapy gowns. Personal protective equipment (PPE) garment is herein understood to be garment worn to minimize exposure to hazards that may cause injuries and / or illnesses. These injuries and / or illnesses may result from contact with chemical, radiological, physical, electrical, mechanical, and / or other workplace hazards. PPE garment is a specific class of PPE and is for example applied in drapes and gowns and should protect the wearer of the PPE garment from the outside environment. These drapes and gowns may be used in the medical field, as well as non-medical field, such as use in clean rooms, or during war fare. For example, particularly in the medical field, the wearer of a PPE garment is protected from environmental elements such as blood, bodyfluids and other liquids as well as virus, bacteria and other microbes, micro-organisms,and / or chemical compounds carried in liquids, such as medicaments, while providingbreathability for vapor, especially water vapor, to combine effective protection for thewearer and a high degree of comfort. Occupational Safety and health Administration (OSHA) stipulates that all personal protective equipment should be safely designed and constructed, and should be maintained in a clean and reliable fashion. It should fit comfortably, encouraging worker use. As used herein, the term "PPE garment" shall be construed broadly to mean all types of garments that provide one or more of the foregoing types of barrier protections. Especially for small highly toxic molecules, such as carmustine, an anti- cancer chemotherapy drug, it is desirable to have a PPE garment, which combines a high barrier against the toxic molecules while having a sufficient breathability. In health care industry, PPE garment has been used for many years in applications such a chemotherapy gowns and surgical isolation gowns. These applications have to comply with for example so-called AAMI standards, which provides standards for liquid barrier performance in the critical zones of gowns and drapes. Over the years, design and construction of PPE garment has evolved. For example, polyolefin films used as viral and bacterial barriers for surgical isolation PPE gowns has been replaced by breathable films for gowns which comply with AAMI level 4. The main driver for the replacement of polyolefin films in surgical isolation gowns was comfort. Chemotherapy gowns are traditionally manufactured from multilayer sheets comprising a non-woven with a polyolefin film. This film is heavy enough to provide an effective barrier against most chemotherapy drugs, but exhibits poor breathability. An effective barrier may be defined by permeation testing according to ASTM F739-20 with a suite of chemotherapy drugs, such as for example carmustine. The time is recorded at which drug permeation exceeds 0.1 microgram / (cm2*min). Customer's requirements vary on the intended application and may usually be at least 30 minutes and may also be higher, such as for example more than 240 minutes. ASTM F3267-22 establishes design, performance, documentation, and labelling requirements for protective clothing used in preventing exposure to liquid chemotherapy and other liquid hazardous drugs. Furthermore, it reiterates that testing should be performed according to ASTM F739-20. According to ASTM F3267-22, broad chemotherapy drug protection is attributed to a fabric that exhibits breakthrough times of at least 30 min for seven specified chemotherapy drugs. While selective chemotherapy drug protection is attributed to a fabric that exhibit breakthrough times of at least 30 min for at least five of the seven specified chemotherapy drugs. For labelling of products, besides breakthrough time, ASTM F3267-22 also recommends specifying the cumulative permeation at 30 min, 60 min and 240 min in order to anticipate workers exposure to drugs. The film in chemotherapy gowns is typically polyethylene or a coextrusion of polyethylene and polypropylene. The film is typically applied to the non- woven by extrusion coating and is typically 50 micrometre to 200 micrometre thick. Twochemotherapy drugs are problematic when tested according to ASTM F739-20.Carmustine and Thiotepa are highly polar and relatively small molecule drugs with high permeation rates. Because of these high permeation rates, most gowns known in the art cannot provide protection for the expected full 4-hour duration. The industry practice to deal with these two drugs is a caution label on the package if the breakthrough time for ASTM F739-20 testing is between 1 hour and 4 hours, and a warning label on the package if the breakthrough time for ASTM F739-20 testing is between 30 minutes and 1 hour. If the breakthrough time in testing is less than 30 minutes for any chemotherapydrug, the industry usually does not accept that product as a protective garment for usewith chemotherapy drugs. Chemotherapy is moving off the hospital ward and into the operating theatre. As part of this shift, there is an expectation that chemotherapy gowns will need similar performance to surgical isolation gowns. Operating theatre staff are expecting their current surgical gowns which are breathable to maintain a similar level of performance with respect to comfort. In addition, they will also require the surgical gown used for chemotherapy procedures in operating theatres to provide similar protection against permeation by chemotherapy drugs relative to what is currently on the market today. The current polyethylene chemo gowns provide protection against most chemotherapy drugsbut provide no or poor breathability. The current surgical gowns provide comfort by way ofmoisture permeability, but do not provide any useful protection against chemotherapy drugs. PRIOR ART Various multilayer sheets and possible use thereof in PPE garment are known from the patent literature, for example, from US2017008211 (D1), US2011 / 039468(D2), and US2004 / 121678 (D3). None of these provides any directions for solving theabove problems for use in chemotherapy gowns. US2017008211 (D1) describes a microporous breathable film, as well as multi-layer breathable barrier films comprising at least one microporous breathable film layer and at least one moisture-permeable barrier layer. The microporous breathable film may be bonded to at least one nonwoven layer. The microporous breathable film and the multi-layer breathable barrier films are reported in US2017008211 (D1) to be suitable for use in personal hygiene products. Herein, the personal hygiene product suitably comprises at least one inner microporous breathable film and at least one outer non- woven layer. The microporous breathable film layer of US2017008211 (D1) typically comprises a polyolefin and an inorganic filler dispersed in the polyolefin. The moisture- permeable barrier layer in the multi-layer breathable barrier films comprises a hygroscopic polymer, such as ^-caprolactone, polyether block amides, polyester elastomer and other polymers. The multilayered breathable films of US2017008211 (D1) are produced by a process comprising a co-extrusion step, i.e. either feed block coextrusion or blown film (tubular) coextrusion, followed by one or more the stretching steps. In the examples of US2017008211 (D1) multi-layer breathable barrier films with an ABCBA structure were produced, with A composed of a polyolefin composition, B a compatibilizer composition and C a polyester elastomer composition, in amounts of A 62.5 wt.%, B 30 wt.% and C 7.5 wt.%. These microporous breathable films so produced had a total basis weight in the range of 5 to 25 gsm. The basis weight of each of the individual layers is as follows: A1.65 - 7.81 gsm, B 0.75 - 3.75 gsm C is 0.38 - 1.88 gsm. According to US2017008211(D1), the monolithic moisture-permeable barrier layer provides an internal viral and alcohol barrier layer, while the multi-layer breathable barrier films of US2017008211 (D1) comprising the same, has high strength and breathability. US2017008211 (D1) is silent about carmustine barrier properties or use in chemotherapy gowns. US2011 / 0039468A1 (US2011 / 039468 (D2)) describes a laminate for protective apparel, which comprises at least one nonwoven layer and a breathable film layer bonded to the nonwoven layer. The monolithic layer is preferably a thermoplastic layer or film. The breathable film layer includes first and second microporous film layers and an internal monolithic (non-porous) layer positioned between the first and second microporous film layers. The monolithic layer may be hygroscopic and include or is blended with an adhesive. Suitable thermoplastic resins for preparing these films include polyolefins, polyesters, polyetheresters, polyamides, polyether amides, ionomers, and urethanes. Information on the production of the multilayer breathable film inUS2011 / 039468 (D2) is limited. The resulting breathable film laminate may be stretchedusing techniques such as machine direction stretching, trans machine stretching, simultaneous or sequential biaxial stretching, stretching on interdigitating rolls and the like.Stretching may also be accomplished by making the film by a blown film process whereinthe film is stretched in all directions by the pressure inside the bubble. The stretching opens micropores in the olefinic layer while thinning and stretching the monolithic layer. The at least one nonwoven layer can be a wide variety of nonwoven fabric constructions, or replaced by a woven, knit, paper or netting layer so long as such layer is compatible with the breathable film layer and provides support and protection therefor. In the single example of US2011 / 039468 (D2), there is described a three-layer laminate material comprising a multilayer, breathable, fluid-impervious film sandwiched between two layers of a nonwoven. The multilayer, breathable, fluid-impervious film was reported to have had a basis weight of 25 gsm, and to consist of 5 layers: 2 micro-porous polyolefin layers of 5.6-5.7 gsm, one of which comprising a compatibilizer, on both sides of a monolithic polyetherester layer of 2.4 gsm. The manufacturer of the multilayer breathable fluid- impervious film was revealed, as well as the supplier of the nonwoven material, but not how these materials were made, let alone any properties or details thereof. US2011 / 039468 (D2) directs to hospital gowns, in particular surgical gowns in operating and emergency rooms, with a special concern for exposure to body fluids such as blood and liquid borne viral penetration. According to US2011 / 039468 (D2), specific embodiments of the laminate of US2011 / 039468 (D2), being liquid impervious and pathogen impervious, or exhibiting resistance to 70% isopropanol, are mentioned suitable for protective apparel. And preferably, the laminate can prevent passage of any virus ofgreater than 25 nm from penetrating through the laminate. In as much as bacteria aresubstantially greater in size than virus, various bacteria will also be prevented from passage. US2011 / 039468 (D2) is silent about carmustine barrier properties or use in chemotherapy gowns. US2004 / 121678 (D3) describes a laminate comprising a breathable layer comprising an antistatic agent and a fibrous layer on the breathable layer. The composite laminate of US2004 / 121678 (D3) can be used, according to US2004 / 121678 (D3), in a garment for use in a medical environment. The breathable layer is preferably a monolithic layer and provides protection from liquids, and from bacterial and viral pathogens such that the laminate exhibits no visible penetration of synthetic blood in a specific test. The breathable monolithic film preferably comprises a copolyetherester andan antistatic agent. The breathable layer has a thickness of about 0.25 - 37.5 μm (0.01 to1.5 mils; 1 mil = 25 μm) and a preferred weight from about 2.35 to 47 gsm (0.1 to about 2 oz / sq.yd; 1 oz = 28.35 gr; 1 sq.yd = 1.1960 sm). Preferably, the fibrous layer includes a thermally activated adhesive material that is used to bond the fibrous layer and the breathable layer together. The fibrous layer can be any type of layer, including woven fabric or non-woven fabric, and of any type of polymer, including polyester elastomer. The fabric fibres can be composed of, but are not limited to, polyester, cellulosic, nylon, polypropylene, polyethylene, or any combination of a blend of such fibres. US2004 / 121678 (D3) comprises two examples. Example 1 concerns a laminate made of a copolyetherester breathable monolithic film, a basis weight 2.62 oz / sy (74.3 gsm), with 0.9 mil (23 μm) laminated to a 14 mil (0.35 mm) nonwoven polyester fabric comprising 15 w.% of an adhesive. In example 2, two fabrics were prepared by carding polyester fibre into a web and introducing 18 percent by weight of a copolyester adhesive powder. The fabrics were placed on either side of a 30 gsm copolyetherester film that contains an antistat and bonded to the copolyetherester film by heating and applying pressure. US2004 / 121678 (D3) is silent about carmustine barrier properties, nor provides directions how to achieve such properties for use in chemotherapy gowns. INVENTION It is thus an object of the present invention to provide a PPE garment which provides sufficient breathability while providing protection against hazardous substances, particularly against carmustine. This object is achieved by the PPE garment according to the present invention comprising a multilayer sheet comprising at least two layers, comprising- at least one monolithic film layer (1) comprising a thermoplastic polymer andhaving a basis weight of at least 10 grams per square meter (gsm) and a breathability as defined by Moisture Vapor Transmission Rate (MVTR) of at least 500 g / (m2*day) as measured according to ASTM E96 protocol B at 38 °C and 50% relative humidity, and- at least one micro-structured porous layer (2) having a basis weight of at least 10grams per square meter (gsm);wherein the layers (1) and (2) have a combined basis weight of at least 30 grams persquare meter (gsm); and wherein the multilayer sheet exhibits an MVTR of at least 250 g / (m2*day), as measured according to ASTM E96 protocol B at 38 °C and 50% relative humidity. In one particularly preferred embodiment, the PPE garment is a chemotherapy gown. The one monolithic film layer (1) comprising a thermoplastic polymer and havinga basis weight of at least 10 grams per square meter (gsm) and a breathability as defined by a Moisture Vapor Transmission Rate (MVTR) of at least 500 g / (m2*day) as measuredaccording to ASTM E96 protocol B at 38 °C and 50% relative humidity, is herein alsoreferred to as breathable monolithic film layer (1)). In a particular embodiment, the multilayer sheet in the PPE garment according to the present invention comprises at least three layers, comprising either at least two of the breathable monolithic film layer (1a, 1b), of which at least one on either side of the micro-structured porous layer (2), or least two of the micro-structured porous layer (2a, 2b), of which at least one on either side of the breathable monolithic film layer (1), wherein the layers (1) and (2) have a combined basis weight of at least 40 grams per square meter (gsm). In another or further embodiment, the multilayer sheet in the PPEgarment according to the present invention exhibits an MVTR of at least 250 g / (m2*day), as measured according to ASTM E96 protocol B at 38 °C and 50% relative humidity and a carmustine break through time at 35 °C of at least 30 min as measured according to standard ASTM F739-20. Advantageously, both the multilayer sheet and garment as a whole can have a MVTR of at least 400 g / (m2*day). Surprisingly, the PPE garment according to the invention exhibits sufficient breathability while providing at least a short-term protection against hazardous substances, particularly against the chemotherapy drug carmustine. Carmustine is known to permeate fast through various materials, hence the low breakthrough times observedfor Carmustine. Other chemotherapy drugs usually exhibit lower diffusion, resulting incomparatively longer breakthrough times. For this reason, Carmustine is usuallyemployed as the test drug of choice, to evaluate break through times. Other chemotherapy drugs are for example, but not limited to: Carboplatin, Cyclophosphamide, Docetaxel, Doxorubicin, Etoposide, Fluorouracil, Paclitaxel, Methotrexate and Thiotepa. This is confirmed by the inventors, which have shown very short Carmustine breakthrough times of less than 1 minute for various individual materials, including breathable monolithic film layers corresponding with layer (1), or a micro-structured porous layer, corresponding with layer (2), as well as other porous materials, each with a basis weight in the range of20 – 30 gsm. The inventors have surprisingly found that the combination of onebreathable monolithic film layer (1) and one micro-structured porous layer (2) provides better carmustine barrier properties than can be expected from the barrier performance of the individual layers. Herein the breathable monolithic film layer (1) and the micro-structured porous layer (2) must have a basis weight of at least 10 gsm each and a combined basis weight of at least 30 gsm. In contrast herewith, for the combination of the breathable monolithic film layer (1) with other porous layered materials, such as aspunbond layer, made of similar materials and with similar basis weight such animprovement was not observed. Furthermore, the inventors have observed that for the multilayer sheet comprising at least three layers, comprising either at least two breathable monolithic film layers (1a, 1b), on either side of the micro-structured porous layer (2), or least two micro-structured porous layers (2a, 2b), on either side of the breathable monolithic film layer (1), the carmustine breakthrough time is significantly further improved, while at the same time the breathability is affected in limited extent only. These results are illustrative for a surprising mutual synergistic effect of the combination of the layers (1) and (2) in the multilayer sheet in the PPE garment according to the present invention. This in contrast with the lack of barrier properties for the individual layers. These results also allow for steering the carmustine breakthrough time, depending on the requirements for the intended application. Figure 1 is a schematic view of a multilayer sheet according to theinvention, comprising two micro-structured porous layers (2a, 2b) on either side of abreathable monolithic film layer (1), wherein the breathable monolithic film layer (1) is denoted by a patterned fill and the micro-structured porous layers (2a, 2b) by a non-fill. DEFINITION OF TERMS The multilayer sheet in the personal protective garment according to the present invention contains at least one breathable monolithic film layer (1) comprising a thermoplastic polymer and at least one micro-structured porous layer (2). The multilayer sheet may comprise two or more breathable monolithic film layers (1), or two or more micro-structured porous layers (2), or two or more of each. Where in the text the singularis used for layer (1) or layer (2), this includes the plural of layers (1), respectively the pluralof layers (2), unless specified otherwise. With the term ‘basis weight’ is herein understood the weight per unitarea. The basis weight of a material layer, being either a breathable monolithic film layer (1) or a micro-structured porous layer (2) used in the PPE garment according to the invention, or any other material layer, is herein expressed in grams per square meter (gsm) and can be measured by cutting a piece from the from material layer, measuring the weight of the piece, expressed in grams, and dividing it by the plan or projectedsurface area of the piece, expressed in square meters (e.g. length × width for arectangular piece or π×radius2for a circular piece). With the term ‘combined basis weight’ , as in ‘the layers (1) and (2) havea combined basis weight’, is herein understood that the sum of the basis weight of layer (1), or where applicable all layers (1) (i.e.1a, 1b, etc), plus the basis weight’ of layer (2), or where applicable, all layers (2) (i.e.2a, 2b, etc). Thus, for a multilayer sheet comprising one layer (1) and two layers (2), i.e. (2a) and (2b), the combined basis weight is the sum of the basis weight of all these three layers. For the monolithic film layer (1) comprising a thermoplastic polymer the basis weight corresponds with the thickness, expressed in micrometres, of the film layer (1), multiplied with the density, expressed in grams per cubic centimetre, of the material from which the monolithic film layer (1) is made. The basis weight of the monolithic film layer (1), or layers (1a, 1b, etc) in the multilayer sheet can thus also be determined by measuring the thickness of each of the film layer (1), or layers (1) in the multilayer sheet, in micrometres, determining the density of the material in the monolithic film layer (1), or layers (1a, 1b, etc), in gsm, and multiplying the measured thickness with the measured density. The basis weight of the micro-structured porous layer (2), or micro- structured porous layers (2a, 2b, etc), in the multilayer sheet can be determined by measuring the combined basis weight of the layers (1) and (2) in the multilayer sheet, and subtracting the basis weight for the monolithic film layer or layers (1). In case of multiple layers (2) with equal thickness, the basis weight of each of the micro-structured porouslayers (2) can be calculated by subtracting the basis weight of the layers (1) from thecombined basis weight and dividing the difference by the number of layers (2). In case of multiple layers (2) with different thicknesses, the calculation is corrected for the differences in thicknesses. The thickness of the monolithic film layer (1) and the micro-structured porous layer (2) can be measured by standard microscopic techniques. In the context of the present invention, with a ‘porous layer’ is herein understood a layer that has many voids distributed over the length and width directions and over the thickness of the layer. The term ‘voids’ refers herein to air pockets or gaps that exist within a layer of material, such as pores in a porous film, or air gaps between fibres in a fibrous web or woven or non-woven fibrous structure. As a result of the large number of voids, such a layer has a substantial porosity, hence the term ‘porous’. With the term ‘micro-structured’ in the expression ‘micro-structured porous layer’ is herein understood a porous layer that is either a microporous film layer, or a micro-fibrous fabric layer. More particular, the micro-structured porous layer in the multilayer sheet of the personal protective equipment (PPE) garment according to the present invention can be- a microporous film layer having pores with a pore size of at most 50 µm, or- a meltblown web layer, or- a woven or non-woven fabric layer made of fibres having a fibre diameter of atmost 10 µm.With the pore size in ‘a pore size of at most 50 µm’, is herein understoodthe pore size measured in in-plane direction with the use of Scanning Electron Microscopy(SEM). Herein the pore size is determined by cross section analysis of SEM images of acryo-fractured microporous film sample. For this purpose, a sample of a microporous filmlayer is broken by cryo-fracturing in two perpendicular directions, resulting in four cryo- fractured surfaces, from which SEM images are made. From these images the pores arecharacterized by a pore size in thickness direction and a pore sizes in an in-planedirection. As the pore size in thickness direction is typically much smaller than the poresize in in-plane direction, it suffices to measure the pore sizes in in-plane direction.With the fibre diameter is herein understood the number average diameter measured with the use of Scanning Electron Microscopy (SEM). SEM is a powerful, high-resolution imaging technique widely used to analyse the structure of fibrousnetworks. With SEM images of a surface area of the microfibrous fabric layer can bemade. Herein the individual fiber diameter of individual fibers is determined by measuringthe dimension of a fiber perpendicular to the length direction of the fiber at an arbitrarypoint. This measurement is done for n different arbitrarily chosen fibers (with n at least100) in a SEM image of the microfibrous layer. The number average fibre diameter iscalculated from the n individual fiber diameters.“Monolithic film” is herein understood to be a continuous film, substantially free of pores and is to be distinguished from porous films, which contain many voids and have a high degree of porosity for permeation purposes. “Breathable monolithic film” is herein understood to be a film capable ofabsorbing water vapor and water molecules on one surface, transferring the moleculesthough the film, and releasing the molecules on the opposite surface. Monolithic films are furthermore excellent barriers for, for example, viruses and bacteria. “Breathable monolithic film layer” is herein understood to comprise at least one monolithic film, and optionally further monolithic films adjacent to each other,thereby forming a layer stack. The term ‘adjacent’ means herein that the surface areas offilms are adjacent, i.e. the surface of each layer is superimposed on or stacked onto or in direct bonding contact with the surface of another film(s). The meaning of the term ‘on either side of’ as used herein is explained for the multilayer sheet comprising at least two breathable monolithic film layers (1a, 1b),of which at least one on either side of the micro-structured porous layer (2). The term ‘oneither side of’ means herein that the surface of one breathable monolithic film layer (1a) is superimposed on or stacked onto or positioned at one side of the micro-structured porous layer (2), whereas one breathable monolithic film layer (1b) is superimposed on or stacked onto or positioned at the other side of the micro-structured porous layer (2), as denoted in Figure 1. Likewise, for the multilayer sheet comprising at least two micro-structured porous layers (2a and 2b), of which at least one on either side of the breathable monolithic film layers (1), the surface of one micro-structured porous layer (2a) is superimposed on or stacked onto or positioned at one side of the breathable monolithic film layer (1), whereas one breathable monolithic film layer (2b) is superimposed on or stacked onto or positioned at the other side of the breathable monolithic film layer (1). The term ‘adjacent’ means herein that the surface areas of layers are adjacent, i.e. the surface of each layer is superimposed on or stacked onto or in direct contact with the surface of another layer(s). A further optional layer may be present between surfaces of the adjacent layers, such as for example an adhesive layer. An example of a multilayer sheet comprising 3 adjacent layers is shown in Figure 1, which shows a schematic view of a multilayer sheet according to the invention, comprising two micro-structured porous layers (2a, 2b) on either side of a breathable monolithic film layer (1). BREATHABLE MONOLITHIC FILM (1, 1a, 1b)The breathable monolithic film (1), or where applicable the breathablemonolithic films (1a, 1b, etc),comprising a thermoplastic polymer comprises one or morethermoplastic polymers from several classes of thermoplastic polymers, for example but not limited to thermoplastic (co)polyamides (TPA), and / or thermoplastic elastomers (TPE) such as thermoplastic copolyesters (TPC), polyether-block-polyamides (PEBA) and thermoplastic polyurethanes (TPU), as well as any blends thereof. Preferably, the breathable monolithic film layer (1, 1a, 1b) comprises athermoplastic copolyester (TPC), as this allows for ease of processing, high breathability and potentially good adhesion properties. Thermoplastic copolyester (TPC) is herein understood to be a copolymer comprising hard segments built up from polyester repeating units derived from at least one aliphatic diol and at least one aromatic dicarboxylic acid or an ester thereof, and soft segments. In a preferred embodiment the thermoplastic copolyester (TPC) comprises soft segments comprising polyethers. Such thermoplastic copolyesters are also known as polyether-block-polyesters or copolyetheresters (COPE). Soft segments are herein understood to originate from aliphatic diols and aliphatic diacids having an Mn of at least 300 g / mol. Mn can be measured by performing end group titrations or NMR spectroscopy, as for example described in J. Serb. Chem. Soc.66 (3) 139-152 (2001). Suitable soft segments include for example polytetramethylene oxide (PTMO), polyethylene oxide (PEO), polypropylene oxide (PPO), block copolymers of poly(ethylene oxide) and poly(propylene oxide), such as for example PEO-PPO-PEO, and combinations thereof. Preferably, the soft segment is a block copolymer of poly(ethylene oxide) and poly(propylene oxide), such as for example PEO- PPO-PEO. Most preferred the soft segment is PEO, as this provides the highest breathability. Preferably, the soft segment has a number average molecular weight (Mn) of not less than 500 g / mol and not more than 8000 g / mol, as this has the advantage that the mechanical properties and processability during film production are sufficient. The number average molecular weight can be measured for a soft segment by NMR spectroscopy. Soft segments may be present in the thermoplastic copolyester elastomer in various amounts and depends on the required hardness and melting temperature. Preferably, the thermoplastic copolyester elastomer comprises between 20 and 80 wt.% of soft segment, wherein wt.% is with respect to the total weight of the thermoplastic copolyester elastomer. More preferably, the amount of soft segment is between 25 to 77 wt.% and even more preferred between 30 and 75 wt.%. Hard segments are built up from polyester repeating units derived from at least one aliphatic diol and at least one aromatic dicarboxylic acid or an ester thereof and optionally minor amounts of other diacids and / or diols. Aliphatic diols contain generally 2 – 10 C-atoms, preferably 2 – 6 C-atoms. Examples thereof include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, butylene glycol, 1,2-hexane diol, 1,6-hexamethylene diol, 1,4-butanediol, 1,4- cyclohexane diol, 1,4-cyclohexane dimethanol, and mixtures thereof. Preferably, 1,4- butanediol is used. Suitable aromatic dicarboxylic acids include terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid and 4,4'-diphenyldicarboxylic acid, and mixtures thereof. The hard segment preferably has as repeating unit chosen from ethylene terephthalate (PET), propylene terephthalate (PPT), butylene terephthalate (PBT), polybutylene isophthalate (PBI), polyethylene isophthalate (PEI), polyethlyene naphthalate, polybutylene naphthalate, and polypropylene naphthalate and combinations thereof. Preferably, the hard segment is PET, PBT, PEI, PBI and combinations thereof. Preferably, the hard segment is PET or PBT, optionally in combination with PEI or PBI. More preferably, the hard segment is PBT optionally in combination with PBI, as thermoplastic copolyester elastomers comprising hard segments of PBT exhibit favourable crystallization behavior and a high melting point, resulting in thermoplastic copolyester elastomer with good processing properties and excellent thermal and chemical resistance wherein PBI hard segments may be used to fine tune the melting temperature and crystallization behavior. Most preferred the hard segment is PBT, as this is readily available. The thermoplastic copolyester elastomer may contain minor amounts of comonomers, such as branching agents and / or chain extenders, as well as catalysts or stabilizers, which are usually employed during preparation of the thermoplastic copolyester elastomer. With minor amounts is herein understood to be at most 10 wt.% with respect to the total amount of thermoplastic copolyester elastomer, preferably at most 5 wt.%. The breathable monolithic film layer (1, 1a, 1b) may comprise further additives, which are as such commonly known in the industry and include for example but not limited to further polymers such as for example polyolefins, such as polyethylene or polypropylene or functionalized polyolefins, nucleating agents, mold-release agents, anti- block additives, colorants, flame-retardants, polytetrafluoroethylene (PTFE), UV stabilizers, heat stabilizers, reinforcing fillers such as glass fibres etc., as long as the overall breathability of the monolithic film layer (1a, 1b) is still sufficient. Breathable TPCs are commercially available from Envalior under the Arnitel trademark, as well as from Dupont under the Hytrel trademark. Examples of commonly used grades are Arnitel VT3104, Arnitel VT3108 and Arnitel EM400, as well as from Dupont such as for example Hytrel 8206 and Hytrel G3548 NC010. Each breathable monolithic film layer (1, 1a, 1b)) may be one single monolithic film layer, but may also be a multi-layered monolithic film layer. The breathable monolithic film layers (1a) and (1b) may preferably be prepared from the same material, which may result in two identical breathable monolithic film layers, but the at least two monolithic film layers (1a) and (1b) may also be prepared from different materials, and / or layer construction. Preferably, each breathable monolithic film layer (1, 1a, 1b) has a moisture vapor transmission rate (MVTR) of at least 500 g / (m2*day), measured according to ASTM E96 protocol B at 38 °C, at 50% relative humidity, more preferably at least 750 g / m2 / day, even more preferably at least 1000 g / (m2*day) and most preferred at least 1400 g / (m2*day). The measurements are performed at 38°C to mimic body temperature. An advantage of a higher MVTR is that vapor may be transported quicker, which provides a more pleasant feel for the wearer. Another advantage of a higher MVTR is that more than one breathable monolithic film layer can be used thereby enhancing the carmustine barrier properties, while still retaining sufficiently high breathability, thereby retainingcomfort while enhancing functional use time of the PPE garment. The MVTRmeasurements on a monolithic film layer in a multilayer sheet can be performed after removal of the micro-structured porous layer (2) and optional further layers and correcting for optional presence of partly non-permeable surfaces, such as but not limited to optional adhesives and / or fabrics, or can be mimicked by preparing a film layer of the same material with the same thickness. The breathable monolithic film layer (1, 1a, 1b) has a basis weight of atleast 10 gsm. The basis weight may vary, and chosen, for example, in relation to thenumber of breathable monolithic film layers (1) in the multilayered sheet, as well as depending on the intended application. The basis weight of the breathable monolithic filmlayers (1, 1a, 1b) may each be as high as, for example, about 100 – 200 gsm, or evenhigher. Preferably, the basis weight of the breathable monolithic film layer (1, 1a, 1b)) is between 10 and 100 gsm, more preferably between 12 and 50 gsm, most preferably between 15 and 40 gsm. The breathable monolithic film layer (1, 1a, 1b) may also have a thickness within a wide range, depending on the intended application of the garment. Thebreathable monolithic film layers (1, 1a, 1b) may each have a thickness of, for example,as low as about 8 micrometre, or, for example, as high as about one hundred fiftymicrometres or more. The thickness suitably is at most 100 micrometre. Preferably, thethickness of each breathable monolithic film layer (1a, 1b)) is between 8 and 80 micrometre, more preferably between 10 and 40 micrometre, most preferably between 12and 35 micrometre. Ensuring a minimum thickness along the entire film mitigates globalhigh permeation rates and / or mitigates or even eliminates high local permeation / leaks. A lower thickness as well as a lower basis weight for the breathable monolithic film layer (1, 1a, 1b) allows for a higher breathability. A higher thickness as well as a higher basis weight has the advantage of better carmustine barrier properties, or that the same carmustine barrier properties can be obtained with a comparatively lowernumber of layers. A lower thickness as well as a lower basis weight for the breathablemonolithic film layer (1, 1a, 1b) also allows for multiple breathable monolithic film layers(1a, 1b, etcetera) to be combined with and alternated by one or more micro-structuredporous layers (2), thereby obtaining further improved carmustine barrier properties whilestill limiting the combined basic weight of the multilayered sheet. PREPARATION OF BREATHABLE MONOLITHIC FILM (1, 1a, 1b) The breathable monolithic film layers (1, 1a, 1b) may be prepared by a variety of ways, which are known in the art per se. The most common technologies are, but not limited to, blown film technology and cast film technology. In cast film technology, a thin film is produced from granulates of a composition by melt-extruding the composition using a screw extruder through a rectangular slit and quenching the melt web on a chill role, thereby obtaining a film. Blown film technology is another extrusion technology used to fabricate films. Granules are melt-extruded, and the melt is transported through a slit,e.g. a circular slit, leading to a hollow melt web, e.g. a cylindrical melt web. The interior ofthis web is pressured by gas, e.g. air, allowing the melt web to further increase in size andallowing the web to cool down and solidify, e.g. on air contact. The solidified material canprocessed downstream to a planar film using known means. As an example, the solidifiedmaterial is transported further downstream through roles / rollers changing the cylindricalshape into a planar shape and a film is created. The breathable monolithic film layer (1, 1a, 1b) may also be prepared in situ by extrusion coating directly onto the micro-structured porous layer (2), and / or by extrusion coating to a further fabric layer after which the micro-structured porous layer (2) is applied and a multilayer sheet is prepared. The breathable monolithic film layers (1, 1a, 1b) may also be prepared in situ by co-extrusion in a process wherein simultaneous the microporous film layer (2) is produced, as will be explained further below. MICRO-STRUCTURED POROUS LAYER (2, 2a, 2b)Due to the presence of voids in the micro-structured porous layer (2), themicro-structured porous layer (2) has a density, referred to as bulk density (BD), which islower than the density of the material from which the micro-structured porous layer (2) ismade. The density of the material as such is herein referred to as specific density (SD).The difference in gross density (BD) and specific density (SD) is determined by therelative volume of voids in the micro-structured porous layer (2), herein referred to asporosity (P). Porosity is determined by the ratio of void volume (Vv) to bulk volume (Vb),and multiplied by 100 when expressed in volume percentage. The porosity can be calculated by the following formula (1): P= 100 (1 – BD / SD) (1)Herein the porosity (P) is expressed in volume percentage, and the gross density (GD) and the specific density (SD) are expressed in grams per cubic centimetre. The porosity (P) can also be derived from the basis weight (BW) and the thickness (T) of the layer and the specific density (SD) of the material in the layer, and be calculated by the following formula (2): P= 100 {1 – BW / (SD x T) } (2)Herein the porosity (P) is also expressed in volume percentage, the basis weight (BW), the specific density (SD) and the thickness are expressed in corresponding units. The micro-structured porous layer (2) can have a porosity varying over awide range. The porosity is suitably at least about 30 %, and can be as high as about 95 % or even higher. Typical values for the porosity are 40 %, 50 % 60 %, 70 %, 80 % and90 %, and any value around or between these values. The micro-structured porous layer(2) can be a microporous film layer or a microfibrous fabric layer. The microfibrous fabriclayer can be a meltblown web layer, or a woven or non-woven layer made of fibres havinga fibre diameter of at most 10 µm. Generally, the meltblown web layer has a higherporosity than the microporous film layer. For example, the meltblown web layer may havea porosity in the range of 60 – 95%, preferably 80 – 95 %. The microporous film layersuitably has a porosity in the range of 30 – 80 %, preferably 30 – 70 %, more preferably35 – 60 %. A higher porosity has the advantage of a higher breathability.The multilayered sheet comprises at least one micro-structured porous layer. The multilayered sheet may comprise more than one micro-structured porous layer. In case of multiple micro-structured porous layers (2) in the multilayered sheet in the garment according to the present invention the micro-structured porous layers (2) layers can consist of multiple microporous film layers, or multiple meltblown web layers, ormultiple microfibrous woven or non-woven layers, or be any combination of micro-structured porous layer mentioned above. In one embodiment of the of the invention, the multilayered sheetcomprises a microporous film layer comprising pores with a pore size of at most 50 µm.The microporous film layer in the multilayered sheet in the PPE garment according to the invention may have pores with a pore size distribution varying over a wide range, fromvery low values of, for example about 1 micrometre or below, up to 50 micrometre. Thepores can have any pore size of 50 micrometre or less, for example, about 30 micrometre, about 20 micrometre, about 10 micrometre, about 5 micrometre, or about 2 micrometre, or any value in between or any combination thereof. Preferably, the pores in the microporous film layer have pore size of at most 40 micrometre, more preferably at most 35 micrometre, even more preferably at most 30 micrometre. The advantage thereof is thatthe multilayered sheet in the PPE garment has better even better carmustine barrierproperties. Microporous film layers can be formed by compounding a specific proportion of an organic or inorganic incompatible particulate material with a small particle size in the range of, for example, a few micrometres, for example 2 micrometres, or 1micrometre, or below, up to about 10 or 15 micrometre, with a polymer that is extrudedand then subjected to unidirectional or bidirectional stretching. Suitable particulate materials or for example inorganic fillers include talc or calcium carbonate. Microporous films prepared from these fillers comprising polymers appear white or silvery as the voids around the talc or calcium carbonate affect transmission of light through the film. In another embodiment of the invention, the micro-structured porous layer (2) in the multilayered sheet comprises a microfibrous fabric layer. Herein the microfibrous fabric layer can be a meltblown web layer, or a woven or non-woven layermade of micro-fibres with a diameter of at most 10 micrometres.Preferably, the micro-structured porous layer (2) comprises a meltblown web layer. The advantage thereof is that high carmustine barrier properties are achieved, while the MVTR is less than with, for example, better than for the multilayered sheetcomprising a microporous film layer having a similar basis weight.Meltblown materials are typically made by a so-called melt-blown non- woven process. In such a process high-speed hot air is used to draw the thin stream ofpolymer melt extruded from a die spinneret, thereby forming ultra-fine fibres andcondensing on the condensing screen curtain or drum, and relying on self-adhesion. Meltblown web layered materials may commercially be purchased from several global suppliers like Mitsui Chemicals America, Inc., Kimberly-Clarck Professional, Mogul Nonwovens and Toray Industries, Inc. In contrast with meltblown web layers, which show surprisingly good results in the multilayered sheet and in the PPE garment according to the present invention, no such results were observed by the inventors for, for example spunbond fabrics. Spunbond fabrics are different from meltblown web layers, and within the context of the present invention, spunbond fabrics are not considered microfibrous fabrics, as spunbond fabrics typically have much larger filament diameters. Spunbond fabrics are typically made by a following process: after the polymer is extruded and stretched to form continuous filaments, the filaments are laid into a web, and the web is then self-bonded and heated. Bonding, chemical bonding or mechanical reinforcement methods are used to turn webs into nonwovens. Spunbond fabrics may commercially be purchased from several global suppliers like Mitsui Chemicals America, Inc., MogulNonwovens and Toray Industries, Inc.. Spunbond-meltblown-spunbond (SMS) fabrics cancommercially be purchased from several global suppliers like Mitsui Chemicals America, Inc., Mogul Nonwovens and Toray Industries, Inc. MATERIALS IN THE MICRO-STRUCTURED POROUS LAYER (2, 2a, 2b) The micro-structured porous layer (2) may be prepared from various materials, such as including but not limited to polyolefins, including polyethylene, polypropylene as well as co-polymers thereof, and polyesters, such as for example PBT, PET, copolyesters, as well as blends thereof, polyamides, natural fibres such as cotton, wool and / or silk. In a preferred embodiment, the micro-structured porous layer (2) comprises a thermoplastic polymer, or even essentially consists of thermoplastic polymer. This has the advantage that adherence to the monolithic film layer (1) or further layerscomprising a thermoplastic polymer may be facilitated with reduced need for adhesive.An advantage of a micro-structured porous layer (2) being made of a polyolefin, is that the carmustine barrier properties are further improved. An advantage of a micro-structured porous layer (2) being made of polyester, is that in combination with breathable monolithic film layers (1a, 1b) comprising or essentially consisting of a thermoplastic copolyester, is that the PPE garment may be recycled. Also the preferred embodiments relating to the thermoplastic copolyester are advantageously employed with a micro-structured porous layer (2) made of polyester. The micro-structured porous layer (2, 2a, 2b) has a basis weight of atleast 10 gsm. The basis weight may vary, and chosen, for example, in relation to thenumber of micro-structured porous layer (2) in the multilayered sheet, as well as depending on the intended application. The basis weight of the micro-structured porouslayer (2, 2a, 2b) may each be as high as, for example, about 120 – 200 gsm, or evenhigher. Preferably, the basis weight of the micro-structured porous layer (2, 2a, 2b) is between 10 and 100 gsm, more preferably between 12 and 80 gsm, most preferably between 15 and 60 gsm. The micro-structured porous layer (2, 2a, 2b) may also have a thicknesswithin a wide range, depending on the intended application of the garment. The micro- structured porous layer (2, 2a, 2b) may each have a thickness of, for example, as low asabout 20 micrometre, or, for example, as high as several hundreds or even about athousand micrometres. In case the micro-structured porous layer (2, 2a, 2b) has a relativelow porosity, say in the range of 30 – 65 %, the thickness of such layer is preferably atmost 500 micrometre, more preferably in the range of 20 – 300 micrometres, even morepreferably in the range of 30 – 200 micrometres. In case the micro-structured porous layer(2, 2a, 2b) has a relative high porosity, say in the range between 65 and 95 %, thethickness suitably is at least 30 micrometres, more preferably in the range of 40 – 750micrometres, even more preferably in the range of 50 – 500 micrometres.A lower basis weight for the micro-structured porous layer (2, 2a, 2b), which can be attained with a lower thickness and / or a higher porosity, allows for a higher breathability. A higher thickness as well as a higher basis weight has the advantage of better carmustine barrier properties, or that the same carmustine barrier properties can be obtained with less layers. A lower thickness as well as a lower basis weight for the micro-structured porous layer (2, 2a, 2b) also allows for multiple micro-structured porous layer(2a, 2b, etcetera) to be combined with and alternated by one or breathable monolithic filmlayer (1), thereby obtaining further improved carmustine barrier properties while stilllimiting the combined basic weight of the multilayered sheet. In a preferred embodiment of the present invention the multilayer sheet comprises at least three layers, comprising at least one breathable monolithic film layer (1a, 1b) on either side of a micro-structured porous layer (2), or at least one micro-structured porous layer (2a, 2b) on either side of a breathable monolithic film layer (1), theall of the layers (1) and (2) have a combined basic weight in the range of 40 – 125 gsm.The garment with such multilayer sheet combines high barrier properties with goodbreathability. Suitably, such multilayer sheet has a thickness in the range of 50 – 1500micrometres. In a more preferred embodiment thereof, the multilayer sheet comprises three layers, comprising two of the micro-structured porous layer (2a, 2b), one on either side of a breathable monolithic film layer (1), wherein each of the layers (1) and (2, 2b)have a basic weight in the range of 10 – 50 gsm, all of the layers (1) and (2) have acombined basic weight in the range of 40 – 125 gsm, and wherein the two micro-structured porous layers (2a, 2b) are meltblown web layers. Such a multilayer sheet combines high breathability, high carmustine barrier properties, easy preparation, and wearing comfort for the user without the need of a further fabric layer. PREPARATION OF THE MULTILAYERED SHEET The multilayer sheet for the personal protective equipment (PPE) garment according to the present invention may be prepared by bonding at least one breathable monolithic film layer (1) on one side of a micro-structured porous layer (2). In case the multilayer sheet for the personal protective equipment (PPE) garment comprises two or more layers (1), the multilayer sheet may be prepared by bonding at least one breathable monolithic film layer (1a, 1b) on either side of a micro-structured porous layer (2). Analogously, in case the multilayer sheet for the personal protective equipment (PPE) garment comprises two or more layers (2), the multilayer sheet may be prepared by bonding at least one micro-structured porous layer (2a, 2b) on either side of a breathable monolithic film layer (1). Bonding may be effected by adhesion such as applying a resin between a micro-structured porous layer (2, 2a, 2b)) and a breathable monolithic film layer (1, 1a, 1b) by for example dot coating or spraying technology. Another technology of bonding is, for example extrusion coating, where mechanical interlocking is the most important adhesion mechanism. For the embodiment, wherein the multilayered sheet comprises a microporous film layer, the multilayered sheet may also be produced by a co-extrusion / stretching process. Herein a first material composition for the breathable monolithic filmlayer (1) and a second material composition for the microporous film layer are coextruded, thereby forming a multilayered sheet comprising a first layer consisting of the first material and a second layer of the second material, followed by stretching the multilayered film,thereby thinning the first layer and creating voids in the second layer, thus simultaneouslyforming the breathable monolithic film layer (1) and the microporous film layer.In a preferred embodiment, the multilayer sheet in the personal protective equipment (PPE) garment is prepared by a lamination process. The lamination process suitably comprising stacking or bonding at least one breathable monolithic film layer (1) and at least micro-structured porous layer (2). The resulting multilayer sheet is a laminated multilayer sheet. This in contrast with a coextruded and stretched multilayer sheet, which can be obtained from a coextrusion and stretching process. The micro-structured porous layer (2) used in the lamination process preferably comprises or is a meltblown web layer. The multilayered sheet is preferably prepared by a process comprising bonding at least one micro-structured porous layer (2a, 2b) on either side of a breathable monolithic film layer (1), or by a process comprising bonding at least one breathable monolithic film layer (1a, 1b), on either side of a micro-structured porous layer (2). This process has the advantages that it is easier and more secure to prepare the multilayered sheet having high carmustine barrier properties. This in contrast with a sheet obtained multilayer sheet obtained from acoextrusion and stretching process. Although such a coextrusion and stretching process may be applied for the preparation of the multilayered sheet, it is more prone to defects, such as rupturing the monolithic film layer (1) during de stretching step, in particular with the monolithic film layer (1) having a thickness at the low side, while on the other side, with the monolithic film layer (1) and / or the micro-structured porous layer (2) having a higher thickness, stretching becomes more difficult, in particular to obtain a homogeneously stretched multilayered sheet. The PPE garment prepared by said process, comprises at least two ofthe breathable monolithic film layer (1a, 1b), or at least two of the micro-structured porouslayer (2a, 2b). Preferably, herein the at least two of the breathable monolithic film layer(1a, 1b), are made from a same material, or the at least two of the micro-structuredporous layer (2a, 2b) are made from another same material. In a preferred embodiment of the above of the PPE garment mentioned herein above, wherein the micro-structured porous layer (2) comprises a meltblown web layer, more preferably a meltblown web layer comprising a polyolefin. In the PPE garment and in the multilayer sheet according to the invention and in the above preferred embodiment the polyolefin based meltblown web layers provide the advantageous combination of a high carmustine barrier properties and high breathability. Moreover, polyolefin based meltblown web layers are readily available. FURTHER FABRIC LAYERS The multilayer sheet in the PPE garment according to the invention mayoptionally comprise one or more further fabric layers (3). These further fabric layers aredifferent from the layers (1) and (2). The further fabric layer or layers (3) can be, forexample woven or non-woven layer made of fibres with diameters larger than 10micrometres, or a spunbond layer, or a porous film comprising pores of more than 50 µm. Such further fabric layers suitably have a high breathability while lacking carmustine barrier properties. The further fabric layers (3) may be present in the multilayer sheet, such as, but not limited to a further fabric layer (3a) adjacent to the breathable monolithic film layer (1) and / or a further fabric layer (3b) adjacent to the breathable monolithic film layer (1b), and even more further fabric layers may be present in the multilayer sheet. Preferably, a further fabric layer (3) is present at least at one outer side of the multilayered sheet, and more preferably a further fabric layer (3a, 3b) is present at either outer side of the multilayered sheet. The advantage thereof is that wearing comfort of the PPE garment made of the multilayered sheet is enhanced, while breathability and carmustine barrier properties are hardly affected. PPE GARMENT The PPE garment according to the invention comprises a multilayer sheet wherein the multilayer sheet exhibits an MVTR of at least 250 g / (m2*day), preferably at least 400 g / (m2*day); even more preferably at least 600g / (m2*day), even more preferably at least 750 g / (m2*day), most preferred at least 1000 g / (m2*day) as measured according to ASTM E96 protocol B at 38 °C and 50% relative humidity. An advantage of a higher MVTR is that the breathability is improved which adds towards the comfort for the wearer. The PPE garment according to the invention comprises a multilayer sheet exhibiting a preferred carmustine break through time at 35±2°C of at least 15 min as measured according to standard ASTM F739-20, more preferably at least 30 min, even more preferably at least 60 min, still even more preferably at least 90 min, and most preferred at least 150 min. A higher carmustine break through time adds towards safetyfor the wearer or caretaker and may prolong the use of the PPE garment, and thus mayreduce the level of waste, as less PPE garment may be needed. A preferred embodiment is a PPE garment comprising a multilayer sheet comprising at least one breathable monolithic film layer (1a, 1b) on either side of a micro- structed porous layer (2), wherein each of the breathable monolithic film layer (1a, 1b) has a Moisture Vapor Transmission Rate (MVTR) of at least 500 g / (m2*day), preferably at least 750 g / (m2*day), more preferably at least 1000 g / (m2*day) and most preferred at least 1400 g / (m2*day), as measured according to ASTM E96 protocol B at 38 °C and 50% relative humidity, and wherein the at least one breathable monolithic film layer (1a, 1b) each comprise a thermoplastic copolyester comprising hard segments of PBT and soft segments chosen from polytetramethylene oxide (PTMO), polyethylene oxide (PEO), polypropylene oxide (PPO), block copolymers of poly(ethylene oxide) and / orpoly(propylene oxide) and wherein the micro-structured porous layer (2) comprises ameltblown web layer. Another preferred embodiment is a PPE garment comprising a multilayer sheet comprising at least one micro-structed porous layer (2a, 2b), on either side of a breathable monolithic film layer (1), wherein the breathable monolithic film layer (1) has a Moisture Vapor Transmission Rate (MVTR) of at least 500 g / (m2*day), preferably at least 750 g / (m2*day), more preferably at least 1000 g / (m2*day) and most preferred at least 1400 g / (m2*day), as measured according to ASTM E96 protocol B at 38 °C and 50% relative humidity, and wherein the breathable monolithic film layer (1) comprises a thermoplastic copolyester comprising hard segments of PBT and soft segments chosen from polytetramethylene oxide (PTMO), polyethylene oxide (PEO), polypropylene oxide (PPO), block copolymers of poly(ethylene oxide) and / or poly(propylene oxide) and wherein each of the micro-structed porous layers (2a, 2b) comprises a meltblown web layer. The Personal Protective equipment garment may be prepared by processes known per se in the art. Usually these employ seaming various multilayer sheets into for example a gown, drape and other uses. Seaming may for example be effected by heat, thereby creating a so-called heat-sealed seam, which is made to be essentially impervious by melting layers of a multilayer sheet when overlapped, and preventing the inner layers from the multilayer sheet from melting. APPLICATIONS The PPE garment according to the invention may be employed in items such as but not limited to gowns, gloves, safety glasses, shoes, earplugs, muffs, hard hats, respirators, or coveralls, vests and / or full body suits. PPE garments include applications in the military, construction, oil and gas, manufacturing, food and beverage as well as in the health care industry. Preferably the PPE garment is a gown used to protect healthcare workers and / or patients for cross-contamination when administering chemotherapy drugs. The PPE garment is preferably a chemotherapy gown, as this requires high barrier towards chemotherapy drugs, for example carmustine. All preferred embodiments mentioned above, are also applicable for the chemotherapy gown according to the invention. The chemotherapy gown may comprise long sleeves, as to further protect the wearer and / or caretaker. The chemotherapy gown preferably has an opening at the back of the wearer, to ensure optimal protection at the front of the wearer. The opening of a chemotherapy gown at the back may have means to close the opening, such as for example a zipper or hook-and-loop material, as for example commercially available under the brand Velcro®, or one or more ribbons, or one or more buttons or combinations thereof. Preferably, the means to close the opening are hook-and-loop material, as this facilitates closing and / or opening. Preferably, the chemotherapy gown according to the invention has a fabric layer facing the wearer, as this enhances comfort for the wearer. This invention also relates to the use of the PPE garment as disclosedabove for the protection of the wearer from the outside environment, such as blood, body fluids and other liquids as well as virus, bacteria and other microbes, micro-organisms,and / or chemical compounds carried in liquids, such as medicaments while providingbreathability for vapor, especially water vapor, to combine effective protection for thewearer and a high degree of comfort. The invention further relates to the use of thechemotherapy gown as disclosed above for the protection of the wearer. The invention is further illustrated with the following Examples and Comparative Experiment. Examples Preparation of the filmsCope 1: thermoplastic copolyester based on 65 wt.% PBT hard segments and 35 wt.%soft segments of PEO with a number average molecular weight of 2000 g / mole. Cope 1 has a melting point of 185°C, a melt volume-flow rate (measured at a weight of 2.16 kg and a temperature of 230 °C) of 10 cm3 / min, a Shore D hardness of 45 and a density of 1250 kg / m3. Weight percentages (wt.%) are denoted with respect to the total weight of the copolyester. Breathable monolithic films, denoted by (A) in Table 1, employed as such in comparative experiment A (CE-A) and used to prepare the multilayer sheet test samples, wereproduced, on a Collin™ cast film line, from granulates as listed in Table 1. Cope 1(melting temperature of 185°C) was fed in pellet form into a single screw extruder andmelted at a temperature of 230 °C and fed to a 400 µm by 30 cm die opening in a heateddie block maintained at 230 °C and casting the film on a chill roll operated at 25 °C and aline speed of 10m / min. All films were produced at a thickness of approximately 30 µm. These films are referred to as Film COPE1. Micro-structured porous layer (2)^ Meltblown web layer: Commercially available material was used: polypropylenebased, 21g / m2, thickness of 300 µm, referred to as MB1 in Table 1. Calculated porosity based on a density of 0.91 gram per cubic centimetre for the polypropylene is 92.3 %.Comparative experiment B^ Comparative experiment B (CE-B) is a commercially purchasedchemotherapy gown from Cardinal Health, named 8200CG (Poly-coated SMSchemotherapy gown). This material comprises a monolithic polyolefin layer.Preparation of multilayer sheet test samples Test samples to mimic multilayer sheets for PPE garments for Examples I-V were prepared by stacking without the use of any adhesive, the individual layers to each other, wherein Film COPE1 denotes the film as prepared in Comparative experiment A. The multilayer sheet structure is provided in Table 1, with A referring to the breathablemonolithic film layer and B referring to the micro-structured porous layer. Example 1 (EX1)was prepared by stacking one breathable monolithic film layer COPE1 and one micro-structured porous layer MB1. Example 2 (EX2) was prepared by stacking one breathablemonolithic film layer COPE1 in-between two micro-structured porous layers MB1.Example 3 (EX3) was prepared by stacking one micro-structured porous layer MB1 in-between two breathable monolithic film layers COPE1. Example 4 (EX4) was prepared byalternatingly stacking two breathable monolithic film layers COPE1 and two micro-structured porous layers MB1. Example 5 (EX5) was prepared by alternatingly stackingtwo breathable monolithic film layers COPE1 and three micro-structured porous layersMB1. Test methods MVTR measurements MVTR measurements were conducted in accordance with ASTM E96 Protocol B, upright cup, water method, at a temperature of 38°C and a relative humidity (RH) of 50%. Carmustine breakthrough time testingThe barrier to the permeation of carmustine posed by garments with varying layer setupwas tested according to ASTM F739-20. In this test, a specimen, selected at random from the monolithic films and multilayer sheets, as denoted in Table 1, served as a membrane to partition two halves of a permeation test cell for liquid challenges. One half of the cell contained the donor solution that is a 10 wt.% ethanol aqueous solution containing 3300 ppm of carmustine, hereafter also referred to as carmustine solution, and the other half contains a 10% ethanol aqueous solution as collection medium, wherein ppm is defined as a weight fraction: 1ppm is 10^-4 wt.% with respect to the total weight of the solution. For non-symmetrical garments, the side facing the donor solution is denoted by [1] in Table 1. Tests were conducted at 35 °C as well as 27±1 °C. At time zero, the test was started by bringing the carmustine solution in contact with the specimen. As carmustine is able to permeate through the specimen, its concentration in the collection medium increases over time. For quantitative determination of the concentration of carmustine, the collection medium was continuously circulated in a closed loop through a UV / VIS Absorption Spectrometer. The concentration of carmustine in the collection medium was used to calculate the permeation rate through the specimen. According to ASTM F739-20, the standardized breakthrough detection time is defined as the time at which permeation rate reaches 0.1 µg / (cm2*min). For measurements at 35 °C, tests were performed for a total time of 240 minutes. Therefore, standardized breakthrough detection times longer than 240 min could not be quantitatively determined. For measurements at 27 °C, tests were performed for a total time of 480 minutes. Three specimens were tested for each monolithic film or multilayer sheet and the test results are shown in Table 1. Testing conditionsPermeation Test Cell Size 1’’ Permeation cellAnalytical method UV / VIS Absorption Spectrometry (wavelength of229nm) on a Perkin Elmer Spectrometer Lambda25Testing temperature 35 °CSpecimen exposed area 5.067 cm2Number of specimens tested 3 per test Test Results Test results for the abovementioned examples and comparative experiments are shown in Table 1. The results for Comparative Experiment A (CE-A)show that the breathable monolithic film layer has very good breathability, but is very pooras a carmustine barrier. On the other hand, as shown for the material of CE-B taken from a Chemotherapy gown, the standard chemotherapy gown has good carmustine barrierproperties, but is poor in breathability,The results for the examples according to the present invention(Examples I-V) show a surprisingly improved balance in properties, wherein thebreathable monolithic film layer (1) and the micro-structured porous layer (2) in themultilayer sheet have a synergistic effect on the carmustine barrier properties while havinga limited effect on the water vapour transmission rate (MVTR). More particular, EX-I, comprising one breathable monolithic film layer (1) and one micro- structured porous layer (2) already shows a measurable effect on the carmustine barrier properties. Such an effect has not been observed by the inventors for similar combinations wherein the micro-structured porous layer (2) was replaced by another layer made of other porous fabric materials, not having the micro-structure of layer (2).Even more particular, in the three-layer systems of Examples II and III, the carmustinebarrier properties are significantly enhanced. Moreover, this holds for the combination ofone breathable monolithic film layer (1) and two micro-structured porous layers (2) as in Example II, as well as for the combination of two breathable monolithic film layer (1) and one micro-structured porous layer (2) as in Example Iii. Apparently, the two types of layers have a mutual synergistic effect on the carmustine barrier properties. It is noticed that withthe combination of Example III, the MVTR is somewhat lower, but still at a high value, butfor the combination of Example II, the MVTR is even hardly affected. As shown byExamples IV and V, even when further increasing the number of layers, the MVTR is stillonly affected in limited extend, while the high carmustine barrier properties are retained.

Claims

CLAIMS1. Personal protective equipment (PPE) garment comprising a multilayer sheetcomprising at least two layers, the multilayer sheet comprising- at least one monolithic film layer (1) comprising a thermoplastic polymer andhaving a basis weight of at least 10 grams per square meter (gsm) and a breathability as defined by a Moisture Vapor Transmission Rate (MVTR) of at least 500 g / (m2*day) asmeasured according to ASTM E96 protocol B at 38 °C and 50% relative humidity (referredto as breathable monolithic film layer (1)); and- at least one micro-structured porous layer (2) having a basis weight of at least 10grams per square meter (gsm); wherein all of the layers (1) and (2) have a combined basis weight of at least 30 grams per square meter (gsm); and the multilayer sheet exhibits an MVTR of at least 250 g / (m2*day), as measured according to ASTM E96 protocol B at 38 °C and 50% relative humidity.

2. PPE garment according to claim 1, wherein the PPE garment is a chemotherapygown.

3. PPE garment according to claim 1 or 2, wherein the at least one micro-structuredporous layer (2) comprises- a microporous film layer having pores with a pore size of at most 50 µm; or- a meltblown web layer; or- a woven or non-woven layer made of fibres having a fibre diameter of at most 10µm (micrometer);- or any multiple or any combination thereof.

4. Personal protective equipment (PPE) garment according to any one of claims 1to 3, wherein the multilayer sheet comprises at least three layers, comprising either at least two of the breathable monolithic film layer (1a, 1b), of which at least one on either side of the micro-structured porous layer (2), or at least two of the micro-structured porous layer (2a, 2b), of which at least one on either side of the breathable monolithic film layer (1), wherein all of the layers (1) and (2) have a combined basis weight of at least 40 grams per square meter (gsm).

5. PPE garment according to any one of claims 1 to 4, wherein themultilayer sheet exhibits- an MVTR of at least 250 g / (m2*day), as measured according to ASTME96 protocol B at 38 °C and 50% relative humidity; and- a carmustine break through time at 35 °C of at least 30 min as measuredaccording to standard ASTM F739-20.

6. PPE garment according to any one of claims 1-5, wherein the at least onebreathable monolithic film layer (1) comprises a thermoplastic polymer chosen fromthermoplastic (co)polyamides (TPA) and thermoplastic elastomers (TPE); preferably a thermoplastic elastomer (TPE) chosen from thermoplastic copolyesters (TPC), polyether- block-polyamides (PEBA) or thermoplastic polyurethanes (TPU), as well as blends thereof.

7. PPE garment according to any one of claims 1-6, wherein the at least onebreathable monolithic film layer (1) comprises a thermoplastic (co)polyester (TPC), preferably a polyether-block-polyester (COPE).

8. PPE garment according to any one of claims 1-7, wherein the micro-structuredporous layer (2) has a porosity in the range of 30 – 95 %.

9. PPE garment according to any one of claims 1-8, wherein the micro-structuredporous layer (2) comprises a polyolefin or a polyester.

10. PPE garment according to any one of claims 1-9, wherein the at least onebreathable monolithic film layer (1) is made of a thermoplastic copolyester and the at leastone micro-structured porous layer (2) is made of a polyester.

11. Personal protective equipment (PPE) garment according to any one of claims 1-10, wherein the multilayer sheet comprises three layers, comprising two of the micro-structured porous layer (2a, 2b), one on either side of a breathable monolithic film layer(1), wherein each of the layers (1) and (2, 2b) have a basic weight in the range of 10 – 50gsm, all of the layers (1) and (2) have a combined basic weight in the range of 40 – 125gsm, and wherein the two micro-structured porous layers (2a, 2b) are meltblown web layers.

12. PPE garment according to any one of claims 1-11, wherein the multilayer sheet isa laminated multilayer sheet.

13. PPE garment according to any one of claims 1-12, wherein the micro-structuredporous layer comprises a meltblown web layer.

14. PPE garment according to any one of claims 1-13, wherein the multilayer sheetcomprises at least three layers, comprising either at least two of the breathable monolithicfilm layer (1a, 1b), of which at least one on either side of the micro-structured porous layer (2), or at least two of the micro-structured porous layer (2a, 2b), of which at least one on either side of the breathable monolithic film layer (1), wherein all of the layers (1) and (2)have a combined basis weight of at least 40 grams per square meter (gsm) andwherein the at least two of the breathable monolithic film layer (1a, 1b), are made from a same material, or wherein the at least two of the micro-structured porous layer (2a, 2b) are made from another same material.

15. Personal protective equipment (PPE) garment according to any one of claims 1-14, wherein the multilayer sheet comprises at least one further fabric layer (3).

16. Use of personal protective equipment (PPE) garment according to any one of theclaims 1-15 for protection of a wearer.

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