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ADVANCED COMPOSITE MATERIALS

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Classification   |    Detailed evidence-based information

Substances Included Synonyms

Therapeutic Toxic Class

    A) Advanced Composite Materials (Advanced Composites) are materials made up of several components, and have mechanical properties superior to those of the components themselves (Dennis, 1992; Kantz, 1989; Carlin, 1989).
    1) Advanced composites based on carbon or graphite fibers in a resin matrix are widely used in the aerospace industry because of their resistance to high temperatures, stiffness, strength, and light weight (Dennis, 1992).
    2) Advanced Composites may also be based on glass, aramid, or quartz (Kantz, 1989).
    3) The resin matrix may be of polystyrene, polyethylene, polyacetal, or epoxy. Epoxy matrices are most common, especially those derived from diglycidyl ether of bisphenol A or 4-glycidiloxy-N,N-diglycidilaniline (Dennis, 1992).
    B) POTENTIAL EXPOSURES
    1) Exposure to the material(s) making up the resin matrix and the fibers (usually carbon or graphite) may occur. Cutting and grinding operations may result in exposure to dust and fibers (Dennis, 1992).
    2) In Advanced Composite production, machining, and maintenance operations, there may also be exposure to solvents, reactive diluents, hardeners, and epoxies (Dennis, 1992).
    3) Exposures to the various components, fibers, and dusts may occur during repair operations (Warnock, 1989a) 1989b).

Specific Substances

    A) COMPONENTS OF THE GROUP
    1) EPOXY RESINS
    2) PREPREG
    3) POLYURETHANE RESINS
    4) PHENOLIC and AMINO RESINS
    5) BISMALEIMIDE RESINS
    6) THERMOPLASTICS
    7) CURING AGENTS/HARDENERS
    8) SOLVENTS-GENERAL
    9) KETONE SOLVENTS
    10) CHLORINATED SOLVENTS
    11) CARBON AND GRAPHITE FIBERS
    12) ARAMID FIBER (KEVLAR(R))
    13) FIBERGLASS FIBERS
    14) CERAMIC FIBERS
    15) OTHER RESIN MATRICES
    16) PMR-15
    17) TRIAZINE/POLYCYANATE RESINS
    18) GRAPHITE, SYNTHETIC
    19) GRAPHITE (ALL FORMS EXCEPT GRAPHITE FIBERS)
    20) GRAFOIL GTA
    21) ASP (GRAPHITE)
    22) GRAFOIL
    23) ELECTROGRAPHITE
    24) CEYLON BLACK LEAD
    25) CANLUB
    26) C (GRAPHITE)
    27) BORAX BLACK PMB
    28) BLACK LEAD
    29) AUP
    30) ATJ
    31) ASSP
    32) PLUMBAGO (GRAPHITE)
    33) ARV
    34) AQUADAG
    35) AQUA-DAG E
    36) AQUA-DAG
    37) AQ
    38) AOP
    39) ACP
    40) ASSP-E
    41) SWEDISH BLACK LEAD
    42) MINERAL CARBON
    43) KOROBON
    44) STOVE BLACK
    45) SHUNGITE
    46) SCHUNGITE
    47) SYNTHETIC GRAPHITE
    48) PAPYEX
    49) SILVER GRAPHITE

Available Forms Sources

    A) FORMS
    1) BASIC STEPS IN ADVANCED COMPOSITES MANUFACTURING (Faoro, 1989):
    a) LAYUP: This step can be done by applying prepreg or using a wet layup of composite material plies followed by application of the resin components on a part mold, followed by trimming.
    1) An alternate method is to over-braid dry fiberglass on insulated ducts, followed by heating and painting with a phenolic-based resin.
    b) CONSOLIDATION/PROCESSING: In this step, the composite part is heated and usually compressed in an autoclave to eliminate voids and to cross-link the matrix.
    c) BREAKOUT: After autoclave processing, the formed part is removed from the forming tool and any bags or wrapping that have been used.
    d) POST-CURE: The formed parts are then further cured in an oven without further compression to allow the matrix to fully cross-link.
    e) MACHINING: TRIMMING is done to cut the part to shape, followed by DRILLING.
    B) SOURCES
    1) The following components are used in the production of Advanced Composite Materials (Dennis, 1992; Schwartz, 1989; Kantz, 1989; Konzen, 1989; 12):
    a) EPOXY RESINS: Epoxy resins are compounds with one or more oxirane rings. They are made by reacting epichlorohydrin and bisphenol A to form a glycidyl group, which is then reacted with hardeners and curing agents (usually amines) to produce an epoxy resin.
    b) PREPREG is a term used for sheets of pyrolized carbon fibers impregnated with a liquid epoxy resin binder and reacted with a curing agent to produce a properly molded piece of thermoset plastic. PREPREGS may be supplied as woven fabrics, roving, and unidirectional tapes.
    c) Nearly all epoxy resins based on bisphenol A have less than 1 ppm epichlorohydrin residual.
    2) POLYURETHANE RESINS: Polyurethane resins are made from polyols (eg, polyether and polyester) and isocyanates (ie, toluene diisocyanate). Methylene diisocyanate and Hexamethylene diisocyanate are also used widely.
    a) Some polyols used in polyurethane resin production contain unreacted ETHYLENE OXIDE.
    3) PHENOLIC AND AMINO RESINS: These are PHENOL-FORMALDEHYDE, UREA-FORMALDEHYDE, AND MELAMINE-FORMALDEHYDE resins.
    a) In the uncured state, PHENOL exposure may occur from direct dermal contact.
    b) During the curing process, inhalation exposure to small amounts of PHENOL and FORMALDEHYDE may occur.
    4) BISMALEIMIDE RESINS: These are polyimides.
    a) MDA (4,4'-Methylene Dianiline) is found as a residual monomer in Bismaleimide resins prior to free-radical cross-linking of the resin with other vinyl compounds.
    5) THERMOPLASTICS: These materials have little potential for harm to exposed humans, with the possible exception of the polystyrenes which may release unreacted styrene monomer under some circumstances.
    6) CURING AGENTS/HARDENERS: These are usually AMINE compounds, including 4,4'-methylene diamine (MDA) and 4,4'-sulfonyl dianiline (DDS, Dapsone). Various aliphatic, cycloaliphatic, and polyaminoamide hardeners may also be used. Some ANHYDRIDE compounds are used as curing agents.
    7) SOLVENTS
    a) GENERAL: A variety of solvents may be used in several stages of Advanced Composite production, including the manufacturing of the component resins and fibers, during the impregnation of reinforcing materials, and in clean-up of tools and the work area. They may be used INAPPROPRIATELY to remove the sticky epoxy resins from the skin.
    b) KETONE SOLVENTS: Acetone and methyl ethyl ketone (MEK) are commonly employed.
    c) CHLORINATED SOLVENTS: A wide variety of chlorinated hydrocarbon solvents may be used in Advanced Composites production, including METHYLENE CHLORIDE, 1,1,1-TRICHLOROETHANE, DIMETHYLFORMAMIDE, AND N-METHYLPYRROLIDONE.
    8) REINFORCING MATERIALS
    a) CARBON AND GRAPHITE FIBERS
    1) GENERAL: The strength of cured Advanced Composite Materials is largely due to the reinforcing materials, which are usually carbon or graphite fibers. After the finished material is produced, exposure to these reinforcing materials occurs during such operations as cutting, drilling, grinding, and sanding.
    2) NUISANCE DUST: The dust generated during the above operations should be controlled as "nuisance dust" according to occupational standards, taking into account the differences between "respirable" and "total" dust particles.
    3) CARBON AND GRAPHITE FIBERS: Are usually now made from polyacrylonitrile (PAN) or petroleum pitch. The temperature of heating to produce the fiber determines the type: carbon fibers are produced by heating the precursor to 1200 degrees C, while graphite fibers are produced by heating the precursor to between 2200 and 2700 degrees C.
    a) Graphite fibers are 1.5 to 2 times as strong as steel.
    b) Such fibers appear to present little or no health hazard risk to humans.
    c) ARAMID FIBER (KEVLAR(R)): Is another type of reinforcing fiber for Advanced Composites.
    d) FIBERGLASS FIBERS: For Advanced Composite Materials reinforcement, the continuous textile fiberglass filament fibers differ from the wool-type; all textile fiberglass fibers have a diameter greater than 6 microns and are thus non-respirable.
    e) CERAMIC FIBERS: Are also used as reinforcing materials in some Advanced Composites.
    9) OTHER RESIN MATRICES
    a) PMR-15: Has been developed for high-temperature resistant structural applications by NASA; the major human health hazard involved is exposure to MDA (4,4'-methylene dianiline) during manufacturing.
    b) TRIAZINE/POLYCYANATE RESINS: Little information is available about the long-term effects of exposure to these materials.
    10) Advanced Composites were first utilized in selected military aircraft (F-111, F-14, F-15, F-16) in the 1960s and 1970s (Anon, 1989; Faoro, 1989; Warnock, 1989a) 1989b).
    a) Other military aircraft with Advanced Composite parts include the B-1B, AV-8B, and the F-18, and retrofitted T-38, A-10, F-111, C-130, and C-141 (Warnock, 1989a) 1989b).
    b) It has been predicted that from 40% to 60% of the next generation of military fighter and attack aircraft will be made of Advanced Composite Materials (Anon, 1989) Warnock, 1989).
    c) Applications for Advanced Composites in military aircraft include fixed-wing aircraft empennage and fuselage structures, wing skins, and various secondary structures; helicopter blades, rotor hubs, and fuselage components; motor cases; missile control surfaces; and engine ducts (Carlin, 1989).
    d) Portions of certain satellites and the space shuttle are made from Advanced Composite Materials (Carlin, 1989).
    e) Nearly all airframes currently being designed utilize Advanced Composite Materials for portions of their structure (Anon, 1989).
    f) CIVILIAN AIRCRAFT: Advanced Composites are used in the 757, 767, Beech Starship, and Voyager civilian aircraft (Carlin, 1989).

Overview

Life Support

    A) This overview assumes that basic life support measures have been instituted.

Clinical Effects

    0.2.1) SUMMARY OF EXPOSURE
    A) LOCAL EFFECTS -
    1) There are LIMITED DATA on the potential toxicity of Advanced Composite Materials.
    a) Skin sensitization, contact dermatitis, as well as eye and skin irritation are seen in Advanced Composites workers.
    b) In one occupational setting, only two workers became ill with allergic contact dermatitis.
    2) Irritation of the mucous membranes of the nose, throat, and upper respiratory tract may occur.
    a) Mechanical irritation of the eyes and mucous membranes may be caused by exposure to fiberglass fibers.
    3) Thermal burns may occur during handling of THERMOPLASTICS in the MOLTEN FORM.
    B) SYSTEMIC EFFECTS -
    1) With exposure to TOLUENE DIISOCYANATE used in polyurethane resin production, respiratory sensitization may occur.
    2) With sufficient exposure to certain AROMATIC AMINE HARDENING COMPOUNDS, METHEMOGLOBINEMIA might occur.
    3) The hardener MDA (4,4-methylene dianiline) can cause liver injury in humans following chronic oral or dermal exposure.
    4) Inhalation overexposure to certain of the solvents used in Advanced Composites production may cause CNS depression (narcosis, incoordination, dizziness, coma, eventual death) and respiratory irritation with the potential for delayed onset of pulmonary edema.
    a) Eye, skin, and mucous membrane irritation may also occur from solvent exposure.
    5) Liver and kidney injury have been described following exposure to the 1,1,1-trichloroethane solvent.
    6) The methylene chloride solvent used in some Advanced Composites can be metabolized to CARBON MONOXIDE following systemic absorption, resulting in potential CARBON MONOXIDE poisoning.
    C) FIBER/DUST EXPOSURE -
    1) During cutting and grinding operations on Advanced Composite Materials, dust or fiber exposure may occur.
    a) In in vitro and in vivo tests, carbon fibers did NOT influence cytotoxicity.
    2) Carbon fibers appear to present little or no health hazard risk to humans. Such fibers do NOT appear to present an asbestos-type health hazard.
    D) OTHER EXPOSURES -
    1) In Advanced Composite production, machining, and maintenance operations, there may also be exposure to solvents, reactive diluents, hardeners, and epoxies.
    E) SPECIFIC COMPONENT(S) EXPOSURES -
    1) Exposure to specific components used in the manufacture of or released from Advanced Composite Materials may occur. Refer to specific chemical TOMES PLUS system documents for more information on toxicity and hazards.
    F) AIRCRAFT ACCIDENTS -
    1) After the crash and burn of a military aircraft, particulate levels from undisturbed wreckage were minimal while levels at or greater than recommended were generated when the wreckage was disturbed for site remediation and investigation.
    0.2.4) HEENT
    A) Eye, nose, throat, and upper respiratory tract irritation may occur.
    0.2.6) RESPIRATORY
    A) Irritation of the mucous membranes of the nose, throat, and upper respiratory tract may occur.
    B) With exposure to TOLUENE DIISOCYANATE used in polyurethane resin production or anhydride curing compounds, respiratory sensitization may occur.
    C) Two-year doses of Kevlar(R) aramid fibers at 500 times the average workplace concentration in rats resulted in slight lung scarring and a type of lung tumor which does not develop in humans. These effects have not been noted in occupationally exposed humans.
    0.2.7) NEUROLOGIC
    A) Inhalation overexposure to certain of the solvents used in Advanced Composites production may cause CNS depression (narcosis, incoordination, dizziness, coma, eventual death).
    0.2.9) HEPATIC
    A) The hardener MDA (4,4-methylene dianiline) can cause liver injury in humans following chronic oral or dermal exposure.
    B) Liver injury has been described following exposure to the 1,1,1-trichloroethane solvent.
    0.2.10) GENITOURINARY
    A) Kidney injury has been described following exposure to the 1,1,1-trichloroethane solvent.
    B) The resin component, EPICHLOROHYDRIN, has caused reversible sterility in male experimental animals.
    C) Certain of the alcohols, glycol ethers, dimethylformamide (DMF), and N-methylpyrrolidine used in production of some Advanced Composites are associated with male reproductive hazards.
    0.2.13) HEMATOLOGIC
    A) With sufficient exposure to certain AROMATIC AMINE HARDENING COMPOUNDS, METHEMOGLOBINEMIA might occur.
    B) The methylene chloride solvent used in some Advanced Composites can be metabolized to CARBON MONOXIDE following systemic absorption, resulting in possible CARBON MONOXIDE poisoning.
    0.2.14) DERMATOLOGIC
    A) Dermal irritation may occur with direct contact, especially with the epoxy resin components.
    B) Dermal sensitization and contact dermatitis may occur in Advanced Composite Materials workers.
    0.2.19) IMMUNOLOGIC
    A) Dermal sensitization and contact dermatitis may occur in Advanced Composite Materials workers.
    B) Elevated titers of IgG or IgM to formaldehyde and IgM to trimellitic anhydride (TMA), as well as activation of the cellular immune system evidenced by the presence of positive TA 1 cells and antibodies to various tissues, were found in some of a group of aircraft workers.
    0.2.20) REPRODUCTIVE
    A) At the time of this review, no data were available to assess the teratogenic potential of this agent.
    B) At the time of this review, no data were available to assess the potential effects of exposure to this agent during pregnancy or lactation.
    0.2.21) CARCINOGENICITY
    A) A variety of the specific components that make up or are used in the production of certain Advanced Composites may be classified as carcinogens. Refer to CARCINOGENICITY in the CLINICAL EFFECTS SECTION of specific chemical TOMES PLUS system documents for more information.
    B) Presently, there are no adequate epidemiological studies either supporting or ruling out graphite dust or fibers as being carcinogenic in humans.
    0.2.22) OTHER
    A) Exposure to specific components used in the manufacture of or released from Advanced Composite Materials may occur. Refer to specific chemical TOMES PLUS system documents for more information on toxicity and hazards.

Laboratory Monitoring

    A) A number of chemicals produce abnormalities of the hematopoietic system, liver, and kidneys. Monitoring complete blood count, urinalysis, and liver and kidney function tests is suggested for patients with significant exposure.
    B) If respiratory tract irritation or respiratory depression is evident, monitor arterial blood gases, chest x-ray, and pulmonary function tests.

Treatment Overview

    0.4.2) ORAL/PARENTERAL EXPOSURE
    A) Ingestion is unlikely to be a significant exposure route for Advanced Composites.
    B) If ingestion of a specific component has occurred, refer to the specific chemical TOMES PLUS system documents for more information.
    0.4.3) INHALATION EXPOSURE
    A) INHALATION: Move patient to fresh air. Monitor for respiratory distress. If cough or difficulty breathing develops, evaluate for respiratory tract irritation, bronchitis, or pneumonitis. Administer oxygen and assist ventilation as required. Treat bronchospasm with an inhaled beta2-adrenergic agonist. Consider systemic corticosteroids in patients with significant bronchospasm.
    B) If respiratory tract irritation or respiratory depression is evident, monitor arterial blood gases, chest x-ray, and pulmonary function tests.
    C) If bronchospasm and wheezing occur, consider treatment with inhaled sympathomimetic agents.
    D) ACUTE LUNG INJURY: Maintain ventilation and oxygenation and evaluate with frequent arterial blood gases and/or pulse oximetry monitoring. Early use of PEEP and mechanical ventilation may be needed.
    0.4.4) EYE EXPOSURE
    A) DECONTAMINATION: Remove contact lenses and irrigate exposed eyes with copious amounts of room temperature 0.9% saline or water for at least 15 minutes. If irritation, pain, swelling, lacrimation, or photophobia persist after 15 minutes of irrigation, the patient should be seen in a healthcare facility.
    0.4.5) DERMAL EXPOSURE
    A) OVERVIEW
    1) DECONTAMINATION: Remove contaminated clothing and jewelry and place them in plastic bags. Wash exposed areas with soap and water for 10 to 15 minutes with gentle sponging to avoid skin breakdown. A physician may need to examine the area if irritation or pain persists (Burgess et al, 1999).
    2) Treat dermal irritation or burns with standard topical therapy. Patients developing dermal hypersensitivity reactions may require treatment with systemic or topical corticosteroids or antihistamines.
    3) Some chemicals can produce systemic poisoning by absorption through intact skin. Carefully observe patients with dermal exposure for the development of any systemic signs or symptoms and administer symptomatic treatment as necessary.

Range Of Toxicity

    A) GENERAL/SUMMARY
    1) The minimum lethal human dose to this agent has not been delineated.
    2) The maximum tolerated human exposure to this agent has not been delineated.

Clinical Effects

Dermatologic

    3.14.1) SUMMARY
    A) Dermal irritation may occur with direct contact, especially with the epoxy resin components.
    B) Dermal sensitization and contact dermatitis may occur in Advanced Composite Materials workers.
    3.14.2) CLINICAL EFFECTS
    A) SKIN IRRITATION
    1) Dermal irritation may occur with direct contact (Dennis, 1992; Schwartz, 1989).
    a) These irritant effects may be due to the epoxy resin components (Dennis, 1992).
    B) HYPERSENSITIVITY REACTION
    1) CONTACT DERMATITIS - Dermal sensitization and contact dermatitis may occur in Advanced Composite Materials workers (Dennis, 1992; Schwartz, 1989; Doyle, 1989).
    a) One case of contact dermatitis has been reported from exposure to bisphenol A in epoxy dimethylacrylate composite dental resin. Such reactions are thought to be rare (Jolanski et al, 1995).

Immunologic

    3.19.1) SUMMARY
    A) Dermal sensitization and contact dermatitis may occur in Advanced Composite Materials workers.
    B) Elevated titers of IgG or IgM to formaldehyde and IgM to trimellitic anhydride (TMA), as well as activation of the cellular immune system evidenced by the presence of positive TA 1 cells and antibodies to various tissues, were found in some of a group of aircraft workers.
    3.19.2) CLINICAL EFFECTS
    A) ACUTE ALLERGIC REACTION
    1) SENSITIZATION - Dermal sensitization and contact dermatitis may occur in Advanced Composite Materials workers (Dennis, 1992; Schwartz, 1989).
    2) AUTOIMMUNE REACTION - Elevated titers of IgG or IgM to formaldehyde and IgM to trimellitic anhydride (TMA), as well as activation of the cellular immune system evidenced by the presence of positive TA 1 cells and antibodies to various tissues (smooth muscle, parietal cell, brush border, mitochondrial, antinuclear), were found in aircraft workers (Breysse, 1989).

Reproductive

    3.20.1) SUMMARY
    A) At the time of this review, no data were available to assess the teratogenic potential of this agent.
    B) At the time of this review, no data were available to assess the potential effects of exposure to this agent during pregnancy or lactation.
    3.20.2) TERATOGENICITY
    A) LACK OF INFORMATION
    1) At the time of this review, no data were available to assess the teratogenic potential of this agent.
    3.20.3) EFFECTS IN PREGNANCY
    A) LACK OF INFORMATION
    1) At the time of this review, no data were available to assess the potential effects of exposure to this agent during pregnancy or lactation.
    3.20.4) EFFECTS DURING BREAST-FEEDING
    A) LACK OF INFORMATION
    1) At the time of this review, no data were available to assess the potential effects of exposure to this agent during pregnancy or lactation.

Summary Of Exposure

    A) LOCAL EFFECTS -
    1) There are LIMITED DATA on the potential toxicity of Advanced Composite Materials.
    a) Skin sensitization, contact dermatitis, as well as eye and skin irritation are seen in Advanced Composites workers.
    b) In one occupational setting, only two workers became ill with allergic contact dermatitis.
    2) Irritation of the mucous membranes of the nose, throat, and upper respiratory tract may occur.
    a) Mechanical irritation of the eyes and mucous membranes may be caused by exposure to fiberglass fibers.
    3) Thermal burns may occur during handling of THERMOPLASTICS in the MOLTEN FORM.
    B) SYSTEMIC EFFECTS -
    1) With exposure to TOLUENE DIISOCYANATE used in polyurethane resin production, respiratory sensitization may occur.
    2) With sufficient exposure to certain AROMATIC AMINE HARDENING COMPOUNDS, METHEMOGLOBINEMIA might occur.
    3) The hardener MDA (4,4-methylene dianiline) can cause liver injury in humans following chronic oral or dermal exposure.
    4) Inhalation overexposure to certain of the solvents used in Advanced Composites production may cause CNS depression (narcosis, incoordination, dizziness, coma, eventual death) and respiratory irritation with the potential for delayed onset of pulmonary edema.
    a) Eye, skin, and mucous membrane irritation may also occur from solvent exposure.
    5) Liver and kidney injury have been described following exposure to the 1,1,1-trichloroethane solvent.
    6) The methylene chloride solvent used in some Advanced Composites can be metabolized to CARBON MONOXIDE following systemic absorption, resulting in potential CARBON MONOXIDE poisoning.
    C) FIBER/DUST EXPOSURE -
    1) During cutting and grinding operations on Advanced Composite Materials, dust or fiber exposure may occur.
    a) In in vitro and in vivo tests, carbon fibers did NOT influence cytotoxicity.
    2) Carbon fibers appear to present little or no health hazard risk to humans. Such fibers do NOT appear to present an asbestos-type health hazard.
    D) OTHER EXPOSURES -
    1) In Advanced Composite production, machining, and maintenance operations, there may also be exposure to solvents, reactive diluents, hardeners, and epoxies.
    E) SPECIFIC COMPONENT(S) EXPOSURES -
    1) Exposure to specific components used in the manufacture of or released from Advanced Composite Materials may occur. Refer to specific chemical TOMES PLUS system documents for more information on toxicity and hazards.
    F) AIRCRAFT ACCIDENTS -
    1) After the crash and burn of a military aircraft, particulate levels from undisturbed wreckage were minimal while levels at or greater than recommended were generated when the wreckage was disturbed for site remediation and investigation.

Heent

    3.4.1) SUMMARY
    A) Eye, nose, throat, and upper respiratory tract irritation may occur.
    3.4.3) EYES
    A) IRRITATION - Eye irritation may occur (Dennis, 1992; Schwartz, 1989).
    3.4.5) NOSE
    A) IRRITATION - Irritation of the mucous membranes of the nose, throat, and upper respiratory tract may occur (Dennis, 1992; Schwartz, 1989).
    3.4.6) THROAT
    A) IRRITATION - Irritation of the mucous membranes of the nose, throat, and upper respiratory tract may occur (Dennis, 1992; Schwartz, 1989).

Respiratory

    3.6.1) SUMMARY
    A) Irritation of the mucous membranes of the nose, throat, and upper respiratory tract may occur.
    B) With exposure to TOLUENE DIISOCYANATE used in polyurethane resin production or anhydride curing compounds, respiratory sensitization may occur.
    C) Two-year doses of Kevlar(R) aramid fibers at 500 times the average workplace concentration in rats resulted in slight lung scarring and a type of lung tumor which does not develop in humans. These effects have not been noted in occupationally exposed humans.
    3.6.2) CLINICAL EFFECTS
    A) IRRITATION SYMPTOM
    1) Irritation of the mucous membranes of the nose, throat, and upper respiratory tract may occur (Dennis, 1992; Schwartz, 1989).
    2) Inhalation overexposure to certain of the solvents used in Advanced Composites production may cause respiratory irritation with the potential for delayed onset of pulmonary edema (Dennis, 1992).
    B) ACUTE ALLERGIC REACTION
    1) SENSITIZATION - With exposure to TOLUENE DIISOCYANATE used in polyurethane resin production or anhydride curing compounds, respiratory sensitization may occur (Dennis, 1992; Schwartz, 1989).
    2) Cross-sensitization may occur with the class of isocyanate compounds (Schwartz, 1989).
    3.6.3) ANIMAL EFFECTS
    A) ANIMAL STUDIES
    a) KEVLAR(R) ARAMID FIBERS - Two-year doses of fibers at 500 times the average workplace concentration in rats resulted in slight lung scarring and a type of lung tumor which does not develop in humans (Merriman, 1989).
    1) These effects have not been noted in occupationally exposed humans.
    b) FIBROSIS - Pulmonary fibrosis was produced rats and hamsters exposed to kaolin-based refractory ceramic fibers (Mast et al, 1995b; McConnell et al, 1995).

Neurologic

    3.7.1) SUMMARY
    A) Inhalation overexposure to certain of the solvents used in Advanced Composites production may cause CNS depression (narcosis, incoordination, dizziness, coma, eventual death).
    3.7.2) CLINICAL EFFECTS
    A) CENTRAL NERVOUS SYSTEM DEFICIT
    1) Inhalation overexposure to certain of the solvents used in Advanced Composites production may cause CNS depression (narcosis, incoordination, dizziness, coma, eventual death) (Dennis, 1992).

Hepatic

    3.9.1) SUMMARY
    A) The hardener MDA (4,4-methylene dianiline) can cause liver injury in humans following chronic oral or dermal exposure.
    B) Liver injury has been described following exposure to the 1,1,1-trichloroethane solvent.
    3.9.2) CLINICAL EFFECTS
    A) LIVER DAMAGE
    1) LIVER INJURY - The hardener MDA (4,4'-methylene dianiline) can cause liver injury in humans following chronic oral or dermal exposure (Dennis, 1992; Schwartz, 1989).
    2) Liver injury has been described following exposure to the 1,1,1-trichloroethane solvent (Dennis, 1992).

Genitourinary

    3.10.1) SUMMARY
    A) Kidney injury has been described following exposure to the 1,1,1-trichloroethane solvent.
    B) The resin component, EPICHLOROHYDRIN, has caused reversible sterility in male experimental animals.
    C) Certain of the alcohols, glycol ethers, dimethylformamide (DMF), and N-methylpyrrolidine used in production of some Advanced Composites are associated with male reproductive hazards.
    3.10.2) CLINICAL EFFECTS
    A) ABNORMAL RENAL FUNCTION
    1) KIDNEY INJURY - Kidney injury has been described following exposure to the 1,1,1-trichloroethane solvent (Dennis, 1992).
    B) MALE REPRODUCTIVE FUNCTION
    1) MALE REPRODUCTIVE HAZARD - The resin component, EPICHLOROHYDRIN, has caused chromosomal changes in humans and reversible sterility in experimental animals (Schwartz, 1989).
    2) MALE REPRODUCTIVE HAZARDS - Certain of the alcohols, glycol ethers, dimethylformamide (DMF), and N-methylpyrrolidine used in production of some Advanced Composites are associated with male reproductive hazards (Schwartz, 1989).

Hematologic

    3.13.1) SUMMARY
    A) With sufficient exposure to certain AROMATIC AMINE HARDENING COMPOUNDS, METHEMOGLOBINEMIA might occur.
    B) The methylene chloride solvent used in some Advanced Composites can be metabolized to CARBON MONOXIDE following systemic absorption, resulting in possible CARBON MONOXIDE poisoning.
    3.13.2) CLINICAL EFFECTS
    A) METHEMOGLOBINEMIA
    1) With sufficient exposure to certain AROMATIC AMINE HARDENING COMPOUNDS, METHEMOGLOBINEMIA might occur (Dennis, 1992).
    a) Refer to the MEDITEXT(R) Medical Management on METHEMOGLOBINEMIA for more information.
    B) CARBOXYHEMOGLOBINEMIA
    1) The methylene chloride solvent used in some Advanced Composites can be metabolized to CARBON MONOXIDE following systemic absorption, resulting in possible CARBON MONOXIDE poisoning (Dennis, 1992).
    a) Refer to specific methylene chloride or dichloromethane TOMES PLUS system documents for more information.

Carcinogenicity

    3.21.2) SUMMARY/HUMAN
    A) A variety of the specific components that make up or are used in the production of certain Advanced Composites may be classified as carcinogens. Refer to CARCINOGENICITY in the CLINICAL EFFECTS SECTION of specific chemical TOMES PLUS system documents for more information.
    B) Presently, there are no adequate epidemiological studies either supporting or ruling out graphite dust or fibers as being carcinogenic in humans.
    3.21.3) HUMAN STUDIES
    A) LACK OF INFORMATION
    1) FORMED ADVANCED COMPOSITES -
    a) At the time of this review, no data were available to assess the carcinogenic potential of this agent.
    2) INDIVIDUAL COMPONENTS OF ADVANCED COMPOSITES -
    a) EPICHLOROHYDRIN - Epichlorohydrin is present in most bisphenol A-derived epoxy resins used in Advanced Composites production. It is considered a probable human carcinogen by the IARC and it is classified as a substances anticipated to be carcinogenic by the National Toxicology Program (NTP) (Dennis, 1992; Schwartz, 1989).
    b) TOLUENE DIISOCYANATE - TDI is used in the production of polyurethane resins and is classified by the IARC as a possible carcinogen (Group 2B) based on animal studies alone (Dennis, 1992). However, the experimental animal bioassay which is the basis of this classification has been disputed (Schwartz, 1989).
    c) FORMALDEHYDE - Formaldehyde is an animal carcinogen. Studies of potential carcinogenicity in humans have been inconclusive to date (Dennis, 1992; Schwartz, 1989).
    d) STYRENE - Based on animal studies, styrene has been classified by the IARC as possibly carcinogenic to humans (Dennis, 1992).
    e) 4,4'-METHYLENE DIANILINE - MDA has been classified as a carcinogen by the National Toxicology Program (NTP), but there are no confirmed reports of human carcinogenicity of this compound (Dennis, 1992; Schwartz, 1989).
    1) An increased incidence of thyroid and liver tumors in rats and mice with chronic MDA exposure has been noted by the NTP (Schwartz, 1989). An excess of bladder tumors was found in a single epidemiologic study in a group of exposed helicopter workers, but to date there are no confirmed reports of MDA carcinogenicity in humans (Schwartz, 1989).
    f) METHYLENE CHLORIDE - The NTP has concluded that methylene chloride is carcinogenic in rodents exposed by inhalation (Dennis, 1992).
    g) 1,1,1-TRICHLOROETHANE - Carcinogenicity studies of 1,1,1-trichloroethane have been inconclusive (Dennis, 1992).
    h) DIMETHYLFORMAMIDE - DMF has been classified by the IARC in its Group 2B, possibly carcinogenic to humans, because of controversial studies that link DMF exposure to development of testicular cancer in humans (Dennis, 1992; Schwartz, 1989).
    i) CARBON FIBERS - The EPA concluded that data were insufficient to classify the carcinogenic potential of carbon fibers (Dennis, 1992).
    1) INADEQUATE EPIDEMIOLOGICAL EVIDENCE - Presently, there are no adequate epidemiological studies either supporting or ruling out graphite dust or fibers as being carcinogenic in humans (Doyle, 1989; Thomson, 1989).
    j) ARAMID (KEVLAR(R)) FIBERS - Based on especially weak experimental animal evidence, the EPA has classified aramid fibers as a "possible human carcinogen" (Dennis, 1992).
    1) Two-year doses of fibers at 500 times the average workplace concentration in rats resulted in slight lung scarring and a type of lung tumor which does not develop in humans (Merriman, 1989).
    k) FIBERGLASS - While textile glass fibers have NOT been shown to be a cancer risk in human and experimental animal studies, FIBERGLASS WOOL which is NOT utilized in Advanced Composites has been classified by the IARC as a possible human carcinogen, based on experimental animal studies with non-natural exposure routes (implantation or injection) (Dennis, 1992; Konzen, 1989).
    l) DGEPBA - (Resins of Bisphenol A and Epichlorohydrin) - Have been reviewed by the IARC and classified as Group 3 (insufficient information to classify the carcinogenic potential) (Schwartz, 1989).
    m) DAPSONE - (DDS, 4,4'-diaminophenylsulfone) - has caused osseous metaplasia and splenic tumors in rats. However, there are significant differences in the metabolism of this compound in rats and humans and these lesions have been speculated to NOT be caused in humans because of the differences in metabolism (Schwartz, 1989).
    n) REFRACTORY CERAMIC FIBERS - There are no published epidemiological studies on possible risks of respiratory cancers in persons exposed to refractory ceramic fibers (Lee et al, 1995). Increased pulmonary tumors and mesotheliomas have been seen in rats and hamsters exposed to refractory ceramic fibers by the inhalation, intratracheal, or intracavitary routes (Mast et al, 1995a; Mast et al, 1995b) McConnell et al, 1995).

Genotoxicity

    A) At the time of this review, no data were available to assess the mutagenic or genotoxic potential of this agent.

Laboratory Monitoring

Monitoring Parameters Levels

    4.1.1) SUMMARY
    A) A number of chemicals produce abnormalities of the hematopoietic system, liver, and kidneys. Monitoring complete blood count, urinalysis, and liver and kidney function tests is suggested for patients with significant exposure.
    B) If respiratory tract irritation or respiratory depression is evident, monitor arterial blood gases, chest x-ray, and pulmonary function tests.
    4.1.2) SERUM/BLOOD
    A) BLOOD/SERUM CHEMISTRY
    1) A number of chemicals produce abnormalities of the hematopoietic system, liver, and kidneys. Monitoring complete blood count and liver and kidney function tests is suggested for patients with significant exposure.
    4.1.3) URINE
    A) URINALYSIS
    1) A number of chemicals produce abnormalities of the hematopoietic system, liver, and kidneys. Monitoring urinalysis is suggested for patients with significant exposure.
    4.1.4) OTHER
    A) OTHER
    1) MONITORING
    a) Advanced Composites workers in one aircraft repair facility exposed to greater than 0.3 mg/cm(3) of respirable dust or 2.0 f/cm(3) of respirable graphite fibers had the following medical monitoring program (Doyle, 1989):
    1) Preplacement baseline and annual pulmonary function testing and physical examination focusing on the eyes, respiratory system, and skin;
    2) Baseline chest x-ray;
    3) Respirator certification for employees who require it;
    4) If METHYLENE DIANILINE exposure is anticipated at 5 ppb in air for 30 or more days yearly or likelihood of greater than 15 days yearly with possible skin contact, baseline and annual liver function tests are added to the above.
    b) One Advanced Composites manufacturer recommends that employees with a history of skin disorders be excluded from work in epoxy-handling operations (Larsen & Scheide, 1989).
    c) When dermal and inhalation workplace exposures are properly controlled, a special medical surveillance program may be unnecessary (Larsen & Scheide, 1989).
    d) If respiratory tract irritation is present, it may be useful to monitor pulmonary function tests.
    e) If respiratory tract irritation is present, monitor arterial blood gases and chest x-ray.

Radiographic Studies

    A) CHEST RADIOGRAPH
    1) If respiratory tract irritation is present, monitor chest x-ray.

Methods

    A) OTHER
    1) Carbon fibers may be detected based on a technique which allows measuring the induced charge acquired by a conducting fiber in an electric field; this technique has a precision of about 2% for fibers in the 1-9 mm range (Loo et al, 1984).
    2) Carbon fiber aerosols may be collected in the impactor of the inlet of a dichotomous sampler (Liu et al, 1983).

Treatment

Life Support

    A) Support respiratory and cardiovascular function.

Patient Disposition

    6.3.3) DISPOSITION/INHALATION EXPOSURE
    6.3.3.5) OBSERVATION CRITERIA/INHALATION
    A) OBSERVATION CRITERIA
    1) Patients symptomatic following exposure should be observed in a controlled setting until all signs and symptoms have fully resolved.

Monitoring

    A) A number of chemicals produce abnormalities of the hematopoietic system, liver, and kidneys. Monitoring complete blood count, urinalysis, and liver and kidney function tests is suggested for patients with significant exposure.
    B) If respiratory tract irritation or respiratory depression is evident, monitor arterial blood gases, chest x-ray, and pulmonary function tests.

Oral Exposure

    6.5.2) PREVENTION OF ABSORPTION
    A) SUMMARY
    1) Ingestion is unlikely to be a significant exposure route for Advanced Composites.
    2) If ingestion of a specific component has occurred, Refer to the specific chemical TOMES PLUS system documents for more information.
    6.5.3) TREATMENT
    A) SUPPORT
    1) Ingestion is unlikely to be a significant route of exposure. Treatment is symptomatic and supportive.

Inhalation Exposure

    6.7.1) DECONTAMINATION
    A) Move patient from the toxic environment to fresh air. Monitor for respiratory distress. If cough or difficulty in breathing develops, evaluate for hypoxia, respiratory tract irritation, bronchitis, or pneumonitis.
    B) OBSERVATION: Carefully observe patients with inhalation exposure for the development of any systemic signs or symptoms and administer symptomatic treatment as necessary.
    C) INITIAL TREATMENT: Administer 100% humidified supplemental oxygen, perform endotracheal intubation and provide assisted ventilation as required. Administer inhaled beta-2 adrenergic agonists, if bronchospasm develops. Consider systemic corticosteroids in patients with significant bronchospasm (National Heart,Lung,and Blood Institute, 2007). Exposed skin and eyes should be flushed with copious amounts of water.
    6.7.2) TREATMENT
    A) IRRITATION SYMPTOM
    1) If respiratory tract irritation or respiratory depression is evident, monitor arterial blood gases, chest x-ray, and pulmonary function tests.
    B) BRONCHOSPASM
    1) If bronchospasm and wheezing occur, consider treatment with inhaled sympathomimetic agents.
    C) ACUTE LUNG INJURY
    1) ONSET: Onset of acute lung injury after toxic exposure may be delayed up to 24 to 72 hours after exposure in some cases.
    2) NON-PHARMACOLOGIC TREATMENT: The treatment of acute lung injury is primarily supportive (Cataletto, 2012). Maintain adequate ventilation and oxygenation with frequent monitoring of arterial blood gases and/or pulse oximetry. If a high FIO2 is required to maintain adequate oxygenation, mechanical ventilation and positive-end-expiratory pressure (PEEP) may be required; ventilation with small tidal volumes (6 mL/kg) is preferred if ARDS develops (Haas, 2011; Stolbach & Hoffman, 2011).
    a) To minimize barotrauma and other complications, use the lowest amount of PEEP possible while maintaining adequate oxygenation. Use of smaller tidal volumes (6 mL/kg) and lower plateau pressures (30 cm water or less) has been associated with decreased mortality and more rapid weaning from mechanical ventilation in patients with ARDS (Brower et al, 2000). More treatment information may be obtained from ARDS Clinical Network website, NIH NHLBI ARDS Clinical Network Mechanical Ventilation Protocol Summary, http://www.ardsnet.org/node/77791 (NHLBI ARDS Network, 2008)
    3) FLUIDS: Crystalloid solutions must be administered judiciously. Pulmonary artery monitoring may help. In general the pulmonary artery wedge pressure should be kept relatively low while still maintaining adequate cardiac output, blood pressure and urine output (Stolbach & Hoffman, 2011).
    4) ANTIBIOTICS: Indicated only when there is evidence of infection (Artigas et al, 1998).
    5) EXPERIMENTAL THERAPY: Partial liquid ventilation has shown promise in preliminary studies (Kollef & Schuster, 1995).
    6) CALFACTANT: In a multicenter, randomized, blinded trial, endotracheal instillation of 2 doses of 80 mL/m(2) calfactant (35 mg/mL of phospholipid suspension in saline) in infants, children, and adolescents with acute lung injury resulted in acute improvement in oxygenation and lower mortality; however, no significant decrease in the course of respiratory failure measured by duration of ventilator therapy, intensive care unit, or hospital stay was noted. Adverse effects (transient hypoxia and hypotension) were more frequent in calfactant patients, but these effects were mild and did not require withdrawal from the study (Wilson et al, 2005).
    7) However, in a multicenter, randomized, controlled, and masked trial, endotracheal instillation of up to 3 doses of calfactant (30 mg) in adults only with acute lung injury/ARDS due to direct lung injury was not associated with improved oxygenation and longer term benefits compared to the placebo group. It was also associated with significant increases in hypoxia and hypotension (Willson et al, 2015).
    D) Treatment should include recommendations listed in the ORAL EXPOSURE section when appropriate.

Eye Exposure

    6.8.1) DECONTAMINATION
    A) EYE IRRIGATION, ROUTINE: Remove contact lenses and irrigate exposed eyes with copious amounts of room temperature 0.9% saline or water for at least 15 minutes. If irritation, pain, swelling, lacrimation, or photophobia persist after 15 minutes of irrigation, an ophthalmologic examination should be performed (Peate, 2007; Naradzay & Barish, 2006).

Dermal Exposure

    6.9.1) DECONTAMINATION
    A) DERMAL DECONTAMINATION
    1) DECONTAMINATION: Remove contaminated clothing and wash exposed area thoroughly with soap and water for 10 to 15 minutes. A physician may need to examine the area if irritation or pain persists (Burgess et al, 1999).
    6.9.2) TREATMENT
    A) IRRITATION SYMPTOM
    1) Treat dermal irritation or burns with standard topical therapy. Patients developing dermal hypersensitivity reactions may require treatment with systemic or topical corticosteroids or antihistamines.
    B) SKIN ABSORPTION
    1) Some chemicals can produce systemic poisoning by absorption through intact skin. Carefully observe patients with dermal exposure for the development of any systemic signs or symptoms and administer symptomatic treatment as necessary.
    C) Treatment should include recommendations listed in the ORAL EXPOSURE section when appropriate.

Range Of Toxicity

Summary

    A) GENERAL/SUMMARY
    1) The minimum lethal human dose to this agent has not been delineated.
    2) The maximum tolerated human exposure to this agent has not been delineated.

Minimum Lethal Exposure

    A) GENERAL/SUMMARY
    1) The minimum lethal human dose to this agent has not been delineated.

Maximum Tolerated Exposure

    A) ANIMAL DATA
    1) BISPHENOL A RESIN - In a 26-week rat feeding study, all animals receiving 5% of the test material in the diet died, while those who received 0.2% experienced no deaths or significant lesions (Schwartz, 1989).
    2) KEVLAR(R) ARAMID FIBERS - Measured exposures to the fibrils during aircraft parts manufacturing did not exceed 0.3 fibrils/mL as an 8-hour TWA (Merriman, 1989).
    3) In experimental animals, no permanent lung damage occurred at doses lower than about 1400 times the average workplace exposure (Merriman, 1989).
    4) GRAPHITE-EPOXY RESIN DUST - 8-Hour TWA Values for airborne levels of graphite-epoxy resin dust found to be associated with listed operations (Bourcier, 1989):
    OPERATIONTOTAL DUST mg/m(3)RESPIRABLE DUST mg/m(3)
    Cutting7.2 +/- 7.84.1 +/- 3.2
    Grinding/ Sanding4.3 +/- 4.11.0 +/- 0.2
    Drilling0.9 +/- 0.4--
    Routing/ Milling3.9 +/- 4.56.5 +/- 6.7
    Mixed4.5 +/- 6.0--
    Total4.1 +/- 4.83.8 +/- 4.8

    5) MILITARY AIRCRAFT CRASH SITE - Sampling for CARBON FIBERS at the site of a AV-8B Harrier aircraft site showed background values of less than 0.1 fiber/cc, while activities by cleanup personnel resulted in 8-hour TWA fiber counts less than 3 fibers/cc (Formisano, 1989).
    6) 4,4'-METHYLENEDIANILINE (MDA) - Air spraying of MDA-containing materials in a paint booth can produce breathing zone concentrations in the range of 5 ppb; however, breathing zone concentrations near a well-controlled filament winder ranged from undetectable to 0.6 ppb (Chalk, 1989).

Physicochemical

Physical Characteristics

    A) In their finished state, Advanced Composite Materials are solids (Dennis, 1992).

Molecular Weight

    A) Varies

References

General Bibliography

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