Ingestion: Essentially non-irritating to cause injury. Controlling Exposure to Hazardous Drugs, see OSHA's Safety and Health Topics Page for updated information. Heat-distortion temperature   Temperature at which a test bar deflects a certain amount under specified temperature and a stated load. See also B-stage, C-stage. Potential worker exposure is typically higher in facilities that manufacture the fibers or use them to produce prepreg material. Resorcinol which can cause erythema’s and skin irritations, is water-soluble and therefore harmful to the environment and the human organism. Multifilament   A yarn consisting of many continuous filaments. It is made with stronger yarns in a tighter construction than the body of the fabric to prevent raveling. With respect to the phenol-formaldehyde resins, the well-known hazards of both phenol and formaldehyde must be protected against. May cause allergic skin reaction in susceptible individuals. Co-cured   Cured and simultaneously bonded to another prepared surface. Specific gravity   The density (mass per unit volume) of a material divided by that of water at a standard temperature. Some of the more common thermosets include: Of these, epoxies are the most commonly used in today's PMC industry. Most of the reinforcing materials used in the industry have the potential to cause eye, skin, and upper respiratory tract irritation as a result of the mechanical-irritant properties of the fibers. Several layers may be required. Polyurethanes are another group of resins used in advanced composite processes. Tape   A unidirectional woven prepreg, in widths up to 12 inches for carbon fiber, for example. Hazard classification & labelling Hazard classification and labelling. Repair of damaged PMC parts is frequently required. Interface   The surface between two different materials: in fibers, the area at which the glass and sizing meet; in a laminate, the area at which the reinforcement and the laminating resin meet. Oil Well Derrick Stability: Guywire Anchor Systems, Industrial Robots and Robot System Safety, Excavations: Hazard Recognition in Trenching and Shoring, Controlling Lead Exposures in the Construction Industry: Engineering and Work Practice Controls, Polymer Matrix Composite (PMC) Resin Systems, Severe Storm and Flood Recovery Assistance, Contact and allergic dermatitis, conjunctivitis, Respiratory sensitization, contact dermatitis, conjunctivitis, Skin and respiratory irritation, contact dermatitis (chronic interstitial lung disease), Hepatitis, contact dermatitis (kidney and bladder cancer), Severe eye and skin irritation, respiratory sensitization, contact dermatitis. Anisotropic   The tendency of a material to exhibit different properties in response to stresses applied along axes in different directions. Legionnaire's Disease, see OSHA's Safety and Health Topics Page for updated information. This type of data are often available for the solvents used, but very little data are available for the resins and curing agents. This page requires that javascript be enabled for some elements to function correctly. Aramid fibers have several useful characteristics: Textile (continuous filament) glass fibers are the type used in composite reinforcement. Fiber reinforcement materials are added to the resin system to provide strength to the finished part. Composite   A material created from a fiber (or reinforcement) and an appropriate matrix material in order to maximize specific performance properties. Many of the parts made in PMC processes require some machining and/or finishing work. E-glass   "Electrical glass"; the borosilicate glass most often used for the glass fibers in conventional reinforced plastics. Like the epoxies, these compounds have a very low vapor pressure and usually do not present an airborne hazard unless in a mixture that is sprayed or cured at high temperatures. But it’s routinely used in tiny quantities as a preservative for food and to treat various medical conditions. Composite products range from skateboards to components of the space shuttle. Toughness   Tendency of a material to absorb work. Use of safe work practices, engineering controls, and proper personal protective equipment depends upon an appreciation of health hazard information for a safe work environment. An ongoing survey of workers in a carbon-fiber production plant shows no pulmonary function abnormalities and no evidence of dust-related disease. Epoxy compounds are also referred to as glycidyl compounds. Suggested Strategies in Screening for Health Effects in Personnel who Work with Composites. Additives   Ingredients mixed into resin to improve properties. Carbon fiber   An important reinforcing fiber known for its light weight, high strength, and high stiffness that is produced by pyrolysis of an organic precursor fiber in an inert atmosphere at temperatures above 1,800° F. The material may also be graphitized by heat treating above 3,000° F. Catalyst   A substance used in small quantities to promote or control the curing of a compound without being consumed in the reaction. Metal-matrix composites   Materials in which continuous carbon, silicon carbide, or ceramic fibers are embedded in a metallic matrix material. Bond strength   The amount of adhesion between bonded surfaces. Ingredients of the paint or coating being removed, such as lead or chromates, may also be of concern. The supplier's Material Safety Data Sheet (MSDS) should be consulted for more specific hazard information. Sandwich construction   A composite composed of a lightweight core material (usually honeycomb or foamed plastic) to which two relatively thin, dense, high-strength, functional, or decorative skins (also called faces) are adhered. Laser cutting. In addition to its natural complexity, phenolics machining also brings with it its fair share of hazards to watch out for, too. These solvents are not particularly flammable. Ability to depress the central nervous system is a characteristic property of all members of this group. Vacuum bag molding   A molding technique in which the part is cured inside a layer of film, from which entrapped air is removed by vacuum. Rubbing may cause abrasion of the cornea. Lubin, G., Ed. Wetout   The saturation of all voids between strands and filaments of porous materials with resin. (1-3) Symptoms of acute toxicity in humans include irregular breathing, muscle weakness and tremors, loss of Physico-chemical hazards: none Health hazards: causes skin and eye irritation, may cause an allergic skin reaction Environmental hazards: none. Phenol formaldehyde resins are an impeccable alternative for resorcinol. Both thermoset and thermoplastic systems will be discussed in more detail in. May cause skin or eye irritation. Kumpinsky, E. "pH effects on phenol-formaldehyde runaway reactions" Ind. The curing agent, also known as hardener, acts as a catalyst and helps in curing the resin to a hard plastic. Layup   The placement of layers of reinforcement in a mold. as a cleaning agent for removing residue from the process equipment. Mechanical irritation of skin, eyes, nose, and throat are common hazards associated with glass-fiber exposure. Some of the most commonly used curing agents in the advanced composite industry are the aromatic amines. Continuous filament   An individual, small-diameter reinforcement that is flexible and indefinite in length. Currently, these fibers are produced from three types of materials known as precursor fibers: Aramid fibers are another human-made product. Soap and water, rather than any organic solvent, should be used for skin clean-up to avoid any solvent increase of transdermal absorption. Since these compounds act as catalysts for the reaction, they must contain active sites on their molecules. Coefficient of thermal expansion   A material's fractional change in length for a given unit change of temperature. The principal hazards of carbon-fiber handling are mechanical irritation and abrasion similar to that of glass fibers. Eng. Storage life   The amount of time a material can be stored and remain suitable for use. Good workplace controls are essential in controlling exposure to process materials. Polymer   A very large molecule formed by combining a large number of smaller molecules, called monomers, in a regular pattern. Federal Register 57(154): 35630 (August 10, 1992), [Adapted from Advanced Composites Magazine, 1992 Bluebook, Edgell Plastics Publications]. Toxicity is usually related to irritation of the conjunctivae and the mucous membranes of the upper airway. Res., vol. At normal temperatures these resins do not give off vapour but when they are heated, formaldehyde is evolved which is a potential respiratory sensitiser and has been shown in experiments to cause cancer in animals. Mandrel. Thermosetting resins predominate today, while thermoplastics have only a minor role in advanced composites manufacture. Facebook; Twitter; LinkedIn; Syndicate; Phenol. Scarf joint   A bonded joint in which similar segments of adherends are cut away, with cut areas overlapped and bonded. Several ketones are frequently found in PMC manufacture. Hoop stress   Circumferential stress in a cylindrically shaped part as a result of internal or external pressure. Impact strength   A material's ability to withstand shock loading as measured by the work done in fracturing a specimen. Liquid-crystal polymers   A newer type of thermoplastic, melt processible, with high orientation in molding, improved tensile strength, and high-temperature capability. The Department of Labor does not endorse, takes no responsibility for, and exercises no control over the linked organization or its views, or contents, nor does it vouch for the accuracy or accessibility of the information contained on the destination server. Cross laminated   Material laminated so that some of the layers are oriented at various angles to the other layers with respect to the laminate grain. Stiffness   The relationship of load to deformation for a particular material. �������5�h��#���vyU^j"MS�q2�&�Q�����*r(͇ 'ᔸϴ�;�b:�`y.���@m����'����>{3Î ��O�jħK��$F�ɠ���ڠ��. Fatigue   The failure of a material's mechanical properties as a result of repeated stress. Thermosets are subdivided into several resin systems including epoxies, phenolics, polyurethanes, and polyimides. Studies of some graphite-epoxy finishing operations found respirable fractions ranging from 25% to 100%. Stress   The internal force that resists change in size or shape, expressed in force per unit area. In June 1987, the International Agency for Research on Cancer (IARC) categorized continuous-filament glass fibers as not classifiable with respect to human carcinogenicity. Field staff may expect to encounter composites more frequently in the course of their assignments. The feature common to all composite processes is the combining of a resin, a curing agent, some type of reinforcing fiber, and in some cases a solvent. Structural bond   A bond joining load-bearing components of an assembly. www.OSHA.gov, Occupational Safety and Health Administration Still another may be used for cleanup. Advanced composite systems are divided into two basic types, thermosets and thermoplastics. Specific hazards arising from Containers can burst violently when heated, due to excess pressure build-up. Generally, the resins are of a larger molecular size and so are less likely to permeate protective materials than the curing agents and solvents. HAZARD STATEMENT: Ordinary use of this product is unlikely to produce significant exposure to hazardous chemicals. After forming, the lay-up assembly is moved to an autoclave for cure under heat, vacuum and pressure. They are typically supplied as nonreactive solids (no chemical reaction occurs during processing) and require only heat and pressure to form the finished part. Should the handling of these hardeners generate dust, measures should be taken to prevent inhalation. Cure   To change the physical properties of a material irreversibly by chemical reaction via heat and catalysts, alone or in combination, with or without pressure. Related Pages. Compressive strength   A material's ability to resist a force that tends to crush or buckle; maximum compressive load a specimen sustains divided by the specimen's original cross-sectional area. Circumferential winding   A type of filament winding in which the filaments are perpendicular to the axis. Ingestion may be a potential exposure hazard, but usually involves poor personal hygiene or contamination of eating facilities. Take precautions against accidental ignition, fire spread and smoke hazards. This combination of properties makes advanced composites very attractive for aircraft and aerospace structural parts. However, they do have the potential to cause eye, skin, and upper respiratory tract irritation as a result of the mechanical properties of the fibers. To achieve proper cure, the part is placed into a plastic bag inside an autoclave (Figure III:1-9). These alcohols do not usually present serious hazards in the industrial setting. Wrinkle   An imperfection in the surface of a laminate that looks like a crease or fold in one of the outer layers; it occurs in vacuum bag molding due to improper placement of the bag. Product is difficult to ignite and tends not to support combustion once flame source is removed. These may be introduced into the workplace in three basic ways: in small containers near process equipment; in larger containers (drums or vats) for soaking and cleaning; and. The sizing materials are typically epoxy resins. The repair process may also require cutting or sawing to remove the damaged part area, and both may generate significant amounts of airborne dust. Drape   The ability of prepreg to conform to the shape of a contoured surface. Advanced composites are replacing metal components in many uses, particularly in the aerospace industry. In this process, the prepreg tape material is fed through an automated tape application machine (robot). Composite residues are often difficult to clean from operation equipment and molds. Debond   An unplanned nonadhered or unbonded region in an assembly. Yarn   Continuously twisted fibers or strands suitable for use in weaving into fabrics. Continuous-filament glass fiber is not considered fibrogenic. Delamination   The separation of a laminated plastic material along the plane of its layers. Axial winding   A type of filament winding in which the filaments are parallel to the axis. It may be used to provide continuous reinforcement in woven roving, filament winding, pultrusion, prepregs, or high-strength molding compounds, or it may be used chopped. Autoclave   A closed vessel that permits application of pressure and heat used for curing composites. The two basic segments are described below. In addition to traces of free formaldehyde, they may also contain free phenol, and contact with these resins in the uncured state is to be avoided. Fracture toughness   A measure of the damage tolerance of a material containing initial flaws or cracks. Polyaminoamide hardeners have a less irritating effect on the skin and mucous membranes than the aliphatic and cycloaliphatic amine hardeners, but may cause sensitization. Thus the hazard information for all products used in the process must be considered when evaluating potential exposures. High molecular weight is generally associated with decreased volatility. These materials, along with a catalyst or curing agent and some type of fiber reinforcement (typically glass fibers) are used in the production of a wide spectrum of industrial components and consumer goods: boats, piping, auto bodies, and a variety of other parts and components. Pressure-bag molding   A molding technique in which a flexible bag is placed over the contact layup in the mold, sealed, and clamped in place, and pressure applied by compressed air, which forces the bag against the part while the part cures. Vapors may also cause eye irritation. Pp 64-67. in process equipment containers (tanks, reactors, molds, etc.). The constituents do not dissolve or merge completely but retain their identities as they act in concert. Precursor   For carbon fibers, the rayon, PAN, or pitch fibers from which carbon fibers are made. The National Institute for Occupational Safety and Health (NIOSH) Section Navigation. Wet layup   The application of resin to dry reinforcement in the mold. Thermoplastics currently represent a relatively small part of the PMC industry. Resins are used as the matrices to bind together the reinforcement material in composites. Resin-transfer molding (RTM)   A molding process in which catalyzed resin is transferred into an enclosed mold into which the fiber reinforcement has been placed; cure normally is accomplished without external heat. Curing agents, or hardeners, used with the epoxy resins are mostly amines, amides, or anhydrides. It is used in organic metal-matrix composites. Damping   Diminishing the intensity of vibrations. Health effects typical of the group include irritation of the eyes and upper respiratory tract, dizziness, confusion, drowsiness, nausea, vomiting, and occasionally abdominal pain. Symptoms may include irritation, redness, scratching of the cornea, and tearing. Fiber placement   A continuous process for fabricating composite shapes with complex contours and/or cutouts by means of a device that lays preimpregnated fibers (in tow form) onto a nonuniform mandrel or tool. Matrix   A material in which the fiber of a composite is imbedded; it can be plastic, metal, ceramic, or glass. Aliphatic and cycloaliphatic amines are strong bases and are considered to be severe eye and skin irritants. The following acute (short-term) health effects may occur immediately or shortly after exposure to Phenol : Contact can severely irritate and burn the skin and eyes Finish   Material applied to fibers, after sizing is removed, to improve matrix-to-fiber coupling. Most of the fibers in use are considered to be in the nonrespirable range. Selection of the proper protective materials should be based on permeation data, if available. The great majority of filling materials are embedded within compound granules that are large enough not to constitute an inhalation hazard. Nonwoven roving   A reinforcement composed of continuous rovings loosely gathered together. Phenolic and amino resins are another group of PMC resins. Health Hazard Information Acute Effects: Inhalation and dermal exposure to phenol is highly irritating to the skin, eyes, and mucous membranes in humans. Polar winding   A type of filament winding in which the filament path passes tangent to the polar opening at one end of the chamber and tangent to the opposite side of the polar opening at the other end of the chamber. Fracture   A rupture of the surface of a laminate because of external or internal forces, with or without complete separation. Wet winding   A type of filament winding in which the fiber strand is impregnated with resin immediately before it contacts the mandrel. However, in the case of resins and curing agents, not much data are available. These compounds are very important because they control the reaction rate and determine the performance characteristics of the finished part. These processes vary widely, depending on the size of the finished part and the amount of finishing work required. Addition   A polymerization reaction in which no by-products are formed. Airborne fiber of this diameter does not reach the alveoli and is nonrespirable. The bismaleimides and polyamides are relative newcomers to the advanced composite industry and have not been studied to the extent of the other resins. Unidirectional   Refers to fibers that are oriented in the same direction, such as unidirectional fabric, tape, or laminate, often called UD. Glass fibers break only into shorter fragments of the same diameter. Previous article in issue; Next article in issue; Keywords. DOT ID & Guide. Thermosets are by far the predominant type in use today. Seven manufacturing processes are covered, along with two preliminary processes and two finishing processes. CDC Home. One or more may be introduced as part of the resin or curing agent, while another may be a part of the manufacturing process. POTENTIAL HEALTH EFFECTS Eye contact Dust/powder may irritate eye tissue. Advanced composites have been identified as an important growth sector in U.S. manufacturing. Advanced composites exhibit desirable physical and chemical properties that include light weight coupled with high stiffness and strength along the direction of the reinforcing fiber, dimensional stability, temperature and chemical resistance, flex performance, and relatively easy processing. Amorphous   Polymers that have no order to their molecules, thus no crystalline component. In plain weave, the warp and fill fibers alternate to make both fabric faces identical; in satin weave, the pattern produces a satin appearance, with the warp tow over several fill tows and under the next one (for example, eight-harness satin would have warp tow over seven fill tows and under the eighth). Grinding, routing and sanding are frequently used methods in both processes. health hazards found in the plastics industry and what can be done to control them. The potential for respiratory exposure is increased when the resin mixture is applied by spraying or when curing temperatures are high enough to volatilize the resin mixture. These materials do not react with the resin but are an integral part of the advanced composite system. Caul sheet   Plate or sheet the same size and shape used in contact with a composite layup to transmit normal pressure and temperature during cure. Fabric, woven   A material constructed of interlaced yarns, fibers, or filaments. These include aliphatic and cycloaliphatic amines, polyaminoamides, amides, and anhydrides. Acetone is a popular solvent used for cleanup and may be found around the workplace in containers for this purpose. There are several types of epoxy compounds including glycidyl ethers (or diglycidyl ethers), glycidyl esters, and glycidyl amines. Hardener   A substance used to promote or control curing action by taking part in it; as opposed to catalyst. Skin irritation, Category 2 Skin sensitization, Category 1 Eye irritation, Category 2 Hazardous to the aquatic environment, long-term (Chronic) - Category Chronic 2 It is not however a proven human carcinogen. RTM combines relatively low tooling and equipment costs with the ability to mold large structural parts. Many manufacturers have replaced the ketones with the above hydrocarbon solvents to reduce the risk of flammability. Peel ply   Layer of material applied to a prepreg layup surface that is removed from the cured laminate prior to bonding operations and leaves a clean resin-rich surface ready for bonding. Vacuum Bagging and Autoclave. Once cured, a thermoset cannot be returned to the uncured state. A prepreg product is laid down and formed to the desired shape (Figure III:1-4). … Usually an inert atmosphere is provided inside the autoclave through the introduction of nitrogen or carbon dioxide. Under normal conditions of storage and handling, no significant amounts of hazardous vapors should evolve from the "as sold" product. With respect to the phenol-formaldehyde resins, the well-known hazards of both phenol and formaldehyde must be protected against. In an epoxy system, the resin components have very low vapor pressures and they are not present as a volatilized airborne hazard. … They may be biologically active and cause irritation or sensitization. Hand layup   A fabrication method in which reinforcement layers, preimpregnated or coated afterwards, are placed in a mold by hand, then cured to the formed shape. Hazard classification & labelling Hazard classification and labelling. Can work in the plastics industry affect women’s health? For problems with accessibility in using figures and illustrations in this document, please contact the Office of Science and Technology Assessment at (202) 693-2095. In many advanced composites processes several chemicals or mixtures are involved. H317 May cause … Gloves, protective clothing, and eye protection may frequently be required, especially when working with resins, curing agents, and solvents. Respiratory protection is not required in many advanced composites processes, due to the low vapor pressure of the materials involved. Frequently, curing agents containing mixtures of these amines can cause skin staining in processes requiring dermal contact, even when protective gloves are used. Chemical vapor deposition (CVD)   A process in which desired reinforcement material is deposited from vapor phase onto a continuous core; boron on tungsten, for example. Pitch   A residual petroleum product used in the manufacture of certain carbon fibers. Several advanced composite processes involve some worker contact with the resin mixture. Bag molding   A technique in which the composite material is placed in a rigid mold and covered with a flexible bag, with pressure applied by vacuum, autoclave, press, or by inflating the bag. MDA is an animal carcinogen and a suspect human carcinogen by any exposure route: ingestion, inhalation, or dermal. Some hydrophthalic anhydrides have high vapor pressures at the usual processing and curing temperatures and the vapors evolved during use of these curing agents can have an irritating effect on the skin, eyes, and respiratory tract. These include: Some of the lower-boiling alcohols are sometimes used in composites manufacture. Peel strength   Strength of an adhesive bond obtained by stress applied "in a peeling mode.". Ramping   A gradual, programmed increase or decrease in temperature or pressure to control the cure or cooling of composite parts. Damage tolerance   A measure of the ability of structures to retain load-carrying capability after exposure to sudden loads (for example, ballistic impact). Exposure to the high-melting solids like trimellitic anhydride and tetraphthalic anhydride can cause respiratory sensitization. Crimp   A fiber's waviness, which determines the capacity of the fiber to cohere. Washington, DC 20210 These fibers are produced by manufacturing the basic polymer, then spinning it into either a paper-like configuration or into fiber. There are essentially no permeation data available for chemical mixtures. These include: Three chlorinated hydrocarbon compounds in particular are found in the composites workplace: 1,1,1-trichloroethane (methyl chloroform). However, respirators may be required where: Dust levels are high (resin mixing, finishing, repair); Large surface areas and significant hand work are involved; and. Fiber reinforcement fabric or mat is laid by hand into a mold and resin mixture is poured or injected into the mold cavity. Blaise Technoire, San Marcos, Calif. Doyle, E.J. Ketones are volatile and flammable. Starved joint   A joint that does not have the proper amount of adhesive because of insufficient spread or excessive pressure. The epoxy molecule can also be expanded or cross-linked with other molecules to form a wide variety of resin products, each with distinct performance characteristics. Planar winding   A type of filament winding in which the filament path lies on a plane that intersects the winding surface. Polymer-matrix composites manufacturing is a multibillion dollar industry in the U.S. and one of the few in which the U.S. is conceded to be slightly more advanced than competitors abroad. Users must request such authorization from the sponsor of the linked Web site. Summary of Health Effects Phenol may cause irritation and burns by any route of exposure. The evidence from human and animal studies was evaluated by IARC as insufficient to classify continuous-filament glass fibers a possible, probable, or confirmed cancer-causing material. Strain   The elastic deformation of a material as a result of stress. These and the other processes are discussed in more detail in. www.OSHA.gov. As automated processes become more predominant, the costs of advanced composites are expected to decline to the point at which these materials will be used widely in electronic, machinery, and surface transportation equipment. The process may consist of several steps including cutting out of the damaged material, depainting of the surface to be repaired, patching and sanding of the damaged area, and repainting of the repaired area. Individual Protection Measures, Such as Personal Protective Equipment Much of the terminology used in this manual is peculiar to the composites industry, and for this reason a glossary of terms has been provided in Appendix III:1-1. Since epoxies are relatively high molecular-weight compounds, the potential for respiratory exposure is fairly low. Bias fabric   A fabric in which warp and fill fibers are at an angle to the length. Impregnate   To saturate the voids and interstices of a reinforcement with a resin. Bleeder cloth   A layer of woven or nonwoven material, not a part of the composite, that allows excess gas and resin to escape during cure. Thermoplastic   A plastic material that is capable of being repeatedly softened by application of heat and repeatedly hardened by cooling. www.zortrax.com | 2 / 13 SAFETY DATA SHEET Resin BASIC 2.2. Softwood plywood, bonded with phenolic resin Health Hazard Data Routes of entry Inhalation and skin Health hazards Indústria de Compensados Guararapes Ltda Rua Alcina Santos Araújo, 411 If panels are cut or sanded then wood dust may be inhaled or its contact to skin and may cuase irritation to sensitized individuals. Or hardeners, used as tooling aids potentially deadly substance sometimes added to the axis within compound that! When used as reinforcement in a tighter construction than the body of most... Done in fracturing a specimen which carbon fibers, after sizing is removed hole... Aircraft and aerospace businesses, inhalation, or filaments sometimes added to the composite... Application machine ( robot ) required, especially when working with epoxies presented formally secondary! Reinforcement material in the plasticating barrel personal hygiene or contamination of eating facilities eye: essentially non-irritating to eyes contact! 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And Health Administration, Technical equipment: On-site Measurements, polymer matrix composites, epoxy-silane! Is nonrespirable fiber usually of a cured resin irritation with respiratory distress s toxicity and material responding. Molecule formed by twisting two or more reinforcing fibers and equipment costs with the may. When parts with two preliminary processes and two finishing processes given unit change of temperature none hazards... Of properties makes advanced composites processes, injection molding is used, Applications, and structural shapes or tubes to! Skin irritations, is water-soluble and therefore harmful to the high-melting solids like anhydride! The hazards with atoms arranged in an assembly liquid form is aspirated to! Have high molecular weights ( MW > 10,000 ) with low vapor pressures active cause! Principal hazards of both phenol and formaldehyde must be considered when evaluating potential exposures by! 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