Contact Us    Contact Us     |     Feedback
MOBILE VIEW  | 

TITANIUM DIOXIDE

Export To Excel

Classification   |    Detailed evidence-based information

Substances Included Synonyms

Therapeutic Toxic Class

    A) Titanium dioxide is used as a paint pigment, in foods, and as a topical protectant.

Specific Substances

    A) No Synonyms were found in group or single elements
    1.2.1) MOLECULAR FORMULA
    1) O2-Ti
    2) TiO2

Available Forms Sources

    A) FORMS
    1) When substantially pure, a massive single crystal (boule) of rutile has the properties of a precious gem. It is translucent with a very light straw color, and with reflectance, refraction and brilliance measuring greater than those of a diamond.
    a) However, this compound lacks the hardness of diamonds. Titania is the name applied to large TiO2 crystals suitable for use in jewelry (Budavari, 1989).
    B) SOURCES
    1) SOURCES
    a) It is found in nature as the minerals rutile (tetragonal), anatase or octahedrite (tetragonal), brookite (orthorhombic), ilmenite (FeTiO3), and perovskite (CaTiO3) (Budavari, 1989).
    C) USES
    1) Of the three forms, anatase is most commonly used in paints. Generally, titanium dioxide is the most desirable white colorant in paints and plastics.
    2) Other industrial uses are in coatings for welding rods, and in foods, drugs, and cosmetics.
    3) COMMON USES-FOODS
    a) Colorant in confections, dairy products, bread flour
    b) Clouding agent in dry beverage mixes
    c) Tobacco wrapping and tobacco substitutes
    4) COMMON USES-MANUFACTURING AND COMMERCIAL
    a) Pigment manufacture. Of all the inorganic white pigments, titanium dioxide perhaps possesses the greatest binding power (ACGIH, 1994).
    b) Welding rod coating materials
    c) Ceramic colorant
    d) Titanium metal source
    e) Production of acid-resistant vitreous enamels, specification paints, exterior white house paints, white interior enamels and lacquers, water paints, shoe whiteners.
    f) Production of acetate rayon, inks, plastics, tanner's leather finishes, glassware, ceramics, floor coverings.
    g) High temperature transducers are made from single crystals (Lewis, 1993).
    h) Manufacture of cosmetics
    i) Titanium dioxide has been used as a photocatalyst to degrade pesticides (Hung & Mak, 1993).
    5) COMMON USES-DRUGS/MEDICAL
    a) Production of sunscreens (HSDB , 1993)
    b) Radioactive skin decontamination (HSDB , 1993)
    c) As an implant material in orthopedics, oral surgery and neurosurgery (Friberg, 1986)
    6) USES BY FORM
    a) Rutile sand is suitable for welding-rod-coating materials, as ceramic colorant, as source of titanium metal, and as a coloring agent in the food industry. High opacity and tinting values are claimed for rutile-like pigments (Budavari, 1989).
    b) Anatase titanium dioxide is used for welding rod coatings, acid resistant vitreous enamels, in specification paints, exterior white house paints, acetate rayon, white interior air-dry and baked enamels and lacquers, inks and plastics, for paper filling and coating, in water paints, tanners' leather finishes, shoe whiteners, and ceramics (Budavari, 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) Titanium dioxide is practically nontoxic and is generally regarded to be biologically inert. Titanium dioxide appears to be innocuous in all but the heaviest dust exposures. Even then, the only consistent effect (irritation) seem to be mild.
    0.2.3) VITAL SIGNS
    A) In heavy dust exposure, cough and dyspnea may be seen. Effects are usually short-lived.
    0.2.4) HEENT
    A) Heavy occupational exposures to the dust have been related to chronic rhinitis.
    0.2.6) RESPIRATORY
    A) Concentrated fumes may irritate the respiratory tract. It is generally classified as a nuisance dust rather than an irritant.
    B) Metal fume fever developed
    C) Heavy occupational exposures to the dust have been related to chronic bronchitis and impaired pulmonary function with radiological findings resembling slight silicosis but without any fibrosis.
    0.2.14) DERMATOLOGIC
    A) Titanium dioxide is virtually harmless on the skin and has been used therapeutically for skin diseases and in dressings for burned skin. One report lists it as a mild irritant after being applied for 3 days to human skin.
    0.2.20) REPRODUCTIVE
    A) No reproductive studies were found for titanium dioxide in either humans or animals. Apparently titanium does not cross the placental barrier in humans, since levels in fetal tissue are undetectable.
    0.2.21) CARCINOGENICITY
    A) Titanium dioxide is a questionable carcinogen when experimental carcinogenic, neoplastigenic, and tumorigenic data are evaluated. NCI carcinogenesis bioassay results were negative.

Laboratory Monitoring

    A) No laboratory measures would be expected to be of value. If severe dyspnea occurs, monitor arterial blood gases.
    B) A chest X-ray may establish titantium dioxide accumulation in patients with long term exposure and dyspnea.

Treatment Overview

    0.4.2) ORAL/PARENTERAL EXPOSURE
    A) Titanium dioxide is minimally toxic. GI decontamination methods after ingestion are not required. No treatment is required after ingestion. Absorption is small, and most titanium dioxide will be eliminated in the feces.
    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.
    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).

Range Of Toxicity

    A) ESTIMATED LETHAL ORAL HUMAN DOSE - > 1 quart.
    B) Ingesting one pound produced no ill effects in one human case.

Clinical Effects

Summary Of Exposure

    A) Titanium dioxide is practically nontoxic and is generally regarded to be biologically inert. Titanium dioxide appears to be innocuous in all but the heaviest dust exposures. Even then, the only consistent effect (irritation) seem to be mild.

Vital Signs

    3.3.1) SUMMARY
    A) In heavy dust exposure, cough and dyspnea may be seen. Effects are usually short-lived.
    3.3.2) RESPIRATIONS
    A) In heavy dust exposure, cough and dyspnea may be seen. Effects are usually short-lived.

Heent

    3.4.1) SUMMARY
    A) Heavy occupational exposures to the dust have been related to chronic rhinitis.
    3.4.5) NOSE
    A) Heavy occupational exposures to the dust have been related to chronic rhinitis (Mickiewicz, 1984).

Respiratory

    3.6.1) SUMMARY
    A) Concentrated fumes may irritate the respiratory tract. It is generally classified as a nuisance dust rather than an irritant.
    B) Metal fume fever developed
    C) Heavy occupational exposures to the dust have been related to chronic bronchitis and impaired pulmonary function with radiological findings resembling slight silicosis but without any fibrosis.
    3.6.2) CLINICAL EFFECTS
    A) IRRITATION SYMPTOM
    1) Concentrated fumes may irritate the respiratory tract.
    a) It is generally classified as a nuisance dust rather than an irritant.
    b) Heavy occupational exposures to the dust have been related to chronic bronchitis and impaired pulmonary function with radiological findings resembling mild silicosis, but without any fibrosis.
    B) UPPER RESPIRATORY INFLAMMATION DUE TO FUMES AND/OR VAPORS
    1) ACUTE TOXICITY
    a) SUMMARY - Concentrated fumes may irritate the respiratory tract (ITI, 1988).
    b) CAUTIONS - In persons with impaired pulmonary function, especially those with obstructive airway disease, breathing titanium dioxide might cause exacerbation of symptoms due to its mild irritant properties (HSDB , 1993).
    C) METAL FEVER
    1) WITH POISONING/EXPOSURE
    a) CASE SERIES - In a college laboratory containing 12 students and 2 staff members, titanium dioxide and hydrogen chloride were released following an experiment with titanium tetrachloride; all developed immediate respiratory irritation, dyspnea and nausea. Up to half of the patients presented with a low-grade fever (over 37 degrees Celsius) which could not be attributed to hydrogen chloride. The presence of fever did not appear dependent on inhalation time or distance from the origin of the smoke. All patients were discharged the following day with normal vital signs. The authors concluded that the low-grade fever was due to titanium dioxide and the symptoms were consistent with findings related to mild metal fume fever (ie, onset of symptoms and spontaneous resolution within 24 to 48 hours) (Otani et al, 2008). Further study is suggested to determine the exact mechanism to produce metal fume fever.
    D) RESPIRATORY FINDING
    1) CHRONIC TOXICITY
    a) Titanium dioxide has been called a mild respiratory irritant from chronic inhalation of the dust (HSDB , 1993). It is generally classified as a nuisance dust rather than an irritant (Hathaway et al, 1991).
    2) OCCUPATIONAL EXPOSURE
    a) CHRONIC TOXICITY - Heavy occupational exposures to the dust have been related to chronic bronchitis and impaired pulmonary function with radiological findings resembling mild silicosis, but without any fibrosis (Friberg et al, 1986).
    b) CASE REPORTS - Titanium dioxide acted as a mild pulmonary irritant in one combined analytic and pathological study done on the lungs of 3 workers who had processed titanium dioxide for 8 to 9 years (Clayton & Clayton, 1982).
    c) CASE SERIES - Recurrent episodes of bronchitis and, presumably, granulomatous lesions in the lungs were reported in Finnish workers who used titanium dioxide as a mordant (Clayton & Clayton, 1982).
    d) EPIDEMIOLOGIC STUDY - A study of 67 subjects in a small titanium oxide paint factory in Nigeria showed 50 to 54% frequency for airway symptoms, 20 to 40% for neurological symptoms, and 10 to 27% for other symptoms. The symptoms were well correlated with exposure (p < 0.05) and pulmonary function tests.
    1) There were 28 (42%) cases of restrictive lung impairment.
    2) Exposure to cotton dust had a confounding influence on the pulmonary function tests of subjects previously exposed. Smoking rate was very low.
    3) These findings indicate the need for worker protection (Oleru, 1987).
    e) EPIDEMIOLOGIC STUDY - A total of 1,576 employees exposed to titanium dioxide were observed from 1956 through 1985 for cancer and chronic respiratory disease incidence, and from 1935 through 1983 for mortality (Chen & Fayerweather, 1988).
    1) A cross sectional sample of 398 employees was evaluated for chest X-ray abnormalities. Cohort analyses suggest that the risks of developing lung cancer and other fatal respiratory diseases were no higher for titanium dioxide exposed employees than for the referent groups.
    2) Nested case control analysis found no statistically significant associations between titanium dioxide exposure and risk of lung cancer, chronic respiratory disease, and chest X-ray abnormalities.
    3) No cases of pulmonary fibrosis were observed among titanium dioxide exposed employees.
    3) ACCUMULATION - In general, titanium does accumulate in the lungs with age (Friberg et al, 1986).
    3.6.3) ANIMAL EFFECTS
    A) ANIMAL STUDIES
    1) RESPIRATORY DISORDER
    a) SUMMARY - Inhalation is expected to produce no major effect greater than that of a nuisance dust.
    b) INTRATRACHEAL INJECTION - Of 20 to 50 mg TIO2 in rats and less than 400 mg in rabbits produced only nonspecific changes related to dust particles (OHM/TADS , 1994).
    c) INHALED DUST
    1) Rats who inhaled TIO2 dust 4 times a day for 5 days per week for up to 13 months did not demonstrate pathological changes 7 months after termination of exposure (OHM/TADS , 1994).
    2) Guinea pigs who were tested similarly showed fibrotic effects and eosinophilic infiltrations after chronic inhalation of 5 days to 4 months (OHM/TADS , 1994).
    3) Inhaled titanium dioxide did not affect several parameters of pulmonary inflammation or injury in rats at a dose of 50 mg/m(3) for 6 hours per day X 5 days (Driscoll et al, 1991).

Dermatologic

    3.14.1) SUMMARY
    A) Titanium dioxide is virtually harmless on the skin and has been used therapeutically for skin diseases and in dressings for burned skin. One report lists it as a mild irritant after being applied for 3 days to human skin.
    3.14.2) CLINICAL EFFECTS
    A) SKIN FINDING
    1) Titanium dioxide is virtually harmless on the skin and has been used therapeutically for skin diseases and in dressings for burned skin (Friberg et al, 1986).
    a) One report lists it as a mild irritant after being applied for 3 days to human skin (HSDB, 1994).
    B) DERMATITIS
    1) STANDARD DRAIZE TEST - HUMAN - At a dose of 300 ug intermittently for 3 days, the reaction was mild (Drill & Lazar, 1977).
    C) LACK OF EFFECT
    1) PROTECTIVE FILM - Titanium dioxide, used as protective film on exposed parts of the body for prevention of flash burns during World War II was without consequence, indicating no capacity of titanium dioxide to produce contact dermatitis, allergic sensitization, or appreciable dermal absorption (HSDB, 1994).

Reproductive

    3.20.1) SUMMARY
    A) No reproductive studies were found for titanium dioxide in either humans or animals. Apparently titanium does not cross the placental barrier in humans, since levels in fetal tissue are undetectable.
    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) PLACENTAL BARRIER
    1) Apparently titanium does not cross the placental barrier in humans, since levels in fetal tissue are undetectable in some cases (Clayton & Clayton, 1982).

Carcinogenicity

    3.21.1) IARC CATEGORY
    A) IARC Carcinogenicity Ratings for CAS13463-67-7 (International Agency for Research on Cancer (IARC), 2016; International Agency for Research on Cancer, 2015; IARC Working Group on the Evaluation of Carcinogenic Risks to Humans, 2010; IARC Working Group on the Evaluation of Carcinogenic Risks to Humans, 2010a; IARC Working Group on the Evaluation of Carcinogenic Risks to Humans, 2008; IARC Working Group on the Evaluation of Carcinogenic Risks to Humans, 2007; IARC Working Group on the Evaluation of Carcinogenic Risks to Humans, 2006; IARC, 2004):
    1) IARC Classification
    a) Listed as: Titanium dioxide
    b) Carcinogen Rating: 2B
    1) The agent (mixture) is possibly carcinogenic to humans. The exposure circumstance entails exposures that are possibly carcinogenic to humans. This category is used for agents, mixtures and exposure circumstances for which there is limited evidence of carcinogenicity in humans and less than sufficient evidence of carcinogenicity in experimental animals. It may also be used when there is inadequate evidence of carcinogenicity in humans but there is sufficient evidence of carcinogenicity in experimental animals. In some instances, an agent, mixture or exposure circumstance for which there is inadequate evidence of carcinogenicity in humans but limited evidence of carcinogenicity in experimental animals together with supporting evidence from other relevant data may be placed in this group.
    3.21.2) SUMMARY/HUMAN
    A) Titanium dioxide is a questionable carcinogen when experimental carcinogenic, neoplastigenic, and tumorigenic data are evaluated. NCI carcinogenesis bioassay results were negative.
    3.21.3) HUMAN STUDIES
    A) CARCINOMA
    1) Titanium dioxide is a questionable carcinogen using experimental carcinogenic, neoplastigenic, and tumorigenic data (Lewis, 1992). NCI carcinogenesis bioassay results were negative (OHM/TADS , 1994).
    2) CASE REPORT - One heavily exposed individual died of brain cancer, showing an accumulation of titanium dioxide in the brain (ILO, 1982).
    3) EPIDEMIOLOGICAL STUDIES have been done on people exposed to titanium dioxide; there is no evidence that it is carcinogenic in man (Friberg et al, 1986).
    4) BLADDER CANCER - A weak association between occupational exposure to titanium dioxide and risk of bladder cancer was seen in a cohort of 484 persons and 1879 controls in Montreal, Quebec, Canada, between 1979 and 1986 (Siemiatycki et al, 1994).
    3.21.4) ANIMAL STUDIES
    A) ROUTE OF EXPOSURE
    1) ORAL - Titanium dioxide has been tested for carcinogenicity in rats and mice at dose levels of 2.5% and 5% in the feed for 103 weeks and was not carcinogenic (NCI, 1978).
    2) ORAL - C-cell adenomas and thyroid carcinomas were increased in female rats receiving titanium dioxide in the diet at levels as high as 50,000 ppm (Clayton & Clayton, 1994).
    3) PARENTERAL - It was also injected intraperitoneally into mice for 18 months and did not produce cancer (Bischoff & Bryson, 1982).
    4) INHALATION of 10, 50, or 250 mg/m(3) for 2 years did not produce any ill effects in rats (Lee, 1985).

Genotoxicity

    A) Titanium dioxide was inactive in the B. subtilis rec assay, a measure of primary damage to DNA. Titanium dioxide was inactive for inducing micronuclei in cultured Chinese hamster ovary cells; it was insoluble in the culture medium.

Laboratory Monitoring

Monitoring Parameters Levels

    4.1.1) SUMMARY
    A) No laboratory measures would be expected to be of value. If severe dyspnea occurs, monitor arterial blood gases.
    B) A chest X-ray may establish titantium dioxide accumulation in patients with long term exposure and dyspnea.
    4.1.2) SERUM/BLOOD
    A) OTHER
    1) No laboratory measures would be expected to be of value.
    B) ACID/BASE
    1) If severe dyspnea occurs, monitor arterial blood gases.

Radiographic Studies

    A) CHEST RADIOGRAPH
    1) A chest X-ray may establish titantium dioxide accumulation in patients with long term exposure and dyspnea.

Methods

    A) MULTIPLE ANALYTICAL METHODS
    1) Urinary Levels may determined by inductively coupled argon plasma, atomic emission spectroscopy. For titanium this method has an estimated detection limit of 0.1 ug/sample. The presision/RSD is 0.16 and the recovery is 86%. The working range is 0.25 to 200 ug for a 50 ml sample (HSDB, 1994).
    a) APPLICABILITY - This is a simultaneous, multielemental analysis, but is not compound specific. Spectral interferences are minimized by wavelength selection, and interelemental factors and background corrections (HSDB, 1994).
    2) AIR SAMPLING - Done with filter or electrostatic precipitator (HSDB, 1994).
    a) ANALYSIS is done by colormetric or gravimetric means. Spectrographically, titanium may be determined at lines 3349.04, 3398.64 and 3989.76 (HSDB, 1994).
    3) QUALITATIVE ANALYSIS - Done by X-ray diffraction (HSDB, 1994).

Treatment

Life Support

    A) Support respiratory and cardiovascular function.

Monitoring

    A) No laboratory measures would be expected to be of value. If severe dyspnea occurs, monitor arterial blood gases.
    B) A chest X-ray may establish titantium dioxide accumulation in patients with long term exposure and dyspnea.

Oral Exposure

    6.5.2) PREVENTION OF ABSORPTION
    A) SUMMARY
    1) Titanium dioxide has little toxicity. Decontamination methods after ingestion are not required.
    B) ACTIVATED CHARCOAL/CATHARTIC
    1) Not required.
    6.5.3) TREATMENT
    A) RECOMMENDATION TO PERFORM TREATMENT
    1) No treatment is required after ingestion. Absorption is minor; most titanium dioxide will be eliminated in the feces.
    B) DILUTION
    1) DILUTION: If no respiratory compromise is present, administer milk or water as soon as possible after ingestion. Dilution may only be helpful if performed in the first seconds to minutes after ingestion. The ideal amount is unknown; no more than 8 ounces (240 mL) in adults and 4 ounces (120 mL) in children is recommended to minimize the risk of vomiting (Caravati, 2004).

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) Evaluate the extent of pulmonary irritation.
    2) Patients with prolonged cough or dyspnea should have a chest x-ray and pulmonary function tests.
    3) Oxygen is seldom necessary, but should be available following significant acute exposure.
    B) 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).

Range Of Toxicity

Summary

    A) ESTIMATED LETHAL ORAL HUMAN DOSE - > 1 quart.
    B) Ingesting one pound produced no ill effects in one human case.

Minimum Lethal Exposure

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

Maximum Tolerated Exposure

    A) ROUTE OF EXPOSURE
    1) Of 15 workers who had been exposed to titanium dioxide dust, three showed radiographic signs in the lungs resembling "slight fibrosis", but disabling injury did not occur. The magnitude and the duration of exposure were not specified (Hathaway et al, 1991).
    2) Titanium dioxide tattooed into the cornea of rabbits and patients having corneal scars has caused permanent white coloration, but no irritation (Grant, 1986).
    B) ANIMAL DATA
    1) Intratracheal injection experiments of titanium dioxide with rats and rabbits generally demonstrate transient effects denoting dusty lungs but overall behavior of titanium dioxide as inert particles (ACGIH, 1986).

Workplace Standards

    A) ACGIH TLV Values for CAS13463-67-7 (American Conference of Governmental Industrial Hygienists, 2010):
    1) Editor's Note: The listed values are recommendations or guidelines developed by ACGIH(R) to assist in the control of health hazards. They should only be used, interpreted and applied by individuals trained in industrial hygiene. Before applying these values, it is imperative to read the introduction to each section in the current TLVs(R) and BEI(R) Book and become familiar with the constraints and limitations to their use. Always consult the Documentation of the TLVs(R) and BEIs(R) before applying these recommendations and guidelines.
    a) Under Study
    1) Titanium dioxide
    a) TLV:
    1) TLV-TWA:
    2) TLV-STEL:
    3) TLV-Ceiling:
    b) Notations and Endnotes:
    1) Carcinogenicity Category: Not Listed
    2) Codes: Not Listed
    3) Definitions: Not Listed
    c) TLV Basis - Critical Effect(s):
    d) Molecular Weight:
    1) For gases and vapors, to convert the TLV from ppm to mg/m(3):
    a) [(TLV in ppm)(gram molecular weight of substance)]/24.45
    2) For gases and vapors, to convert the TLV from mg/m(3) to ppm:
    a) [(TLV in mg/m(3))(24.45)]/gram molecular weight of substance
    e) Additional information:
    b) Adopted Value
    1) Titanium dioxide
    a) TLV:
    1) TLV-TWA: 10 mg/m(3)
    2) TLV-STEL:
    3) TLV-Ceiling:
    b) Notations and Endnotes:
    1) Carcinogenicity Category: A4
    2) Codes: Not Listed
    3) Definitions:
    a) A4: Not Classifiable as a Human Carcinogen: Agents which cause concern that they could be carcinogenic for humans but which cannot be assessed conclusively because of a lack of data. In vitro or animal studies do not provide indications of carcinogenicity which are sufficient to classify the agent into one of the other categories.
    c) TLV Basis - Critical Effect(s): LRT irr
    d) Molecular Weight: 79.9
    1) For gases and vapors, to convert the TLV from ppm to mg/m(3):
    a) [(TLV in ppm)(gram molecular weight of substance)]/24.45
    2) For gases and vapors, to convert the TLV from mg/m(3) to ppm:
    a) [(TLV in mg/m(3))(24.45)]/gram molecular weight of substance
    e) Additional information:

    B) NIOSH REL and IDLH Values for CAS13463-67-7 (National Institute for Occupational Safety and Health, 2007):
    1) Listed as: Titanium dioxide
    2) REL:
    a) TWA:
    b) STEL:
    c) Ceiling:
    d) Carcinogen Listing: (Ca) NIOSH considers this substance to be a potential occupational carcinogen (See Appendix A in the NIOSH Pocket Guide to Chemical Hazards).
    e) Skin Designation: Not Listed
    f) Note(s): See Appendix A
    3) IDLH:
    a) IDLH: 5000 mg/m3
    b) Note(s): Ca
    1) Ca: NIOSH considers this substance to be a potential occupational carcinogen (See Appendix A).

    C) Carcinogenicity Ratings for CAS13463-67-7 :
    1) ACGIH (American Conference of Governmental Industrial Hygienists, 2010): Not Listed ; Listed as: Titanium dioxide
    2) ACGIH (American Conference of Governmental Industrial Hygienists, 2010): A4 ; Listed as: Titanium dioxide
    a) A4 :Not Classifiable as a Human Carcinogen: Agents which cause concern that they could be carcinogenic for humans but which cannot be assessed conclusively because of a lack of data. In vitro or animal studies do not provide indications of carcinogenicity which are sufficient to classify the agent into one of the other categories.
    3) EPA (U.S. Environmental Protection Agency, 2011): Not Listed
    4) IARC (International Agency for Research on Cancer (IARC), 2016; International Agency for Research on Cancer, 2015; IARC Working Group on the Evaluation of Carcinogenic Risks to Humans, 2010; IARC Working Group on the Evaluation of Carcinogenic Risks to Humans, 2010a; IARC Working Group on the Evaluation of Carcinogenic Risks to Humans, 2008; IARC Working Group on the Evaluation of Carcinogenic Risks to Humans, 2007; IARC Working Group on the Evaluation of Carcinogenic Risks to Humans, 2006; IARC, 2004): 2B ; Listed as: Titanium dioxide
    a) 2B : The agent (mixture) is possibly carcinogenic to humans. The exposure circumstance entails exposures that are possibly carcinogenic to humans. This category is used for agents, mixtures and exposure circumstances for which there is limited evidence of carcinogenicity in humans and less than sufficient evidence of carcinogenicity in experimental animals. It may also be used when there is inadequate evidence of carcinogenicity in humans but there is sufficient evidence of carcinogenicity in experimental animals. In some instances, an agent, mixture or exposure circumstance for which there is inadequate evidence of carcinogenicity in humans but limited evidence of carcinogenicity in experimental animals together with supporting evidence from other relevant data may be placed in this group.
    5) NIOSH (National Institute for Occupational Safety and Health, 2007): Ca ; Listed as: Titanium dioxide
    a) Ca : NIOSH considers this substance to be a potential occupational carcinogen (See Appendix A in the NIOSH Pocket Guide to Chemical Hazards).
    6) MAK (DFG, 2002): Not Listed
    7) NTP (U.S. Department of Health and Human Services, Public Health Service, National Toxicology Project ): Not Listed

    D) OSHA PEL Values for CAS13463-67-7 (U.S. Occupational Safety, and Health Administration (OSHA), 2010):
    1) Listed as: Titanium dioxide (Total dust)
    2) Table Z-1 for Titanium dioxide (Total dust):
    a) 8-hour TWA:
    1) ppm:
    a) Parts of vapor or gas per million parts of contaminated air by volume at 25 degrees C and 760 torr.
    2) mg/m3: 15
    a) Milligrams of substances per cubic meter of air. When entry is in this column only, the value is exact; when listed with a ppm entry, it is approximate.
    3) Ceiling Value:
    4) Skin Designation: No
    5) Notation(s): Not Listed

Toxicity Information

    7.7.1) TOXICITY VALUES
    A) Reference: Lewis, 1992
    1) TCLo- (INHALATION)RAT:
    a) 250 mg/m(3) for 6H, 2Y-I -- CAR

Pharmacology Toxicology

Pharmacologic Mechanism

    A) ENZYMES - The effect of inhalation exposure to silica or titanium dust on enzymes was examined in lung lavage fluid from guinea pigs (Sjostrand & Rylander, 1984).
    1) Guinea pigs were exposed to aerosols containing 6, 13, or 28 mg/cu meter of silicon dioxide or 24 mg/cu m titanium dioxide for 8 hours per day, 5 days per week, for 3 weeks.
    2) Animals were killed at various times after exposure and lungs were lavaged. Fluid was centrifuged and lactate dehydrogenase was determined in supernatants. Enzyme activities were assayed.
    3) In animals exposed to aerosols containing titanium dioxide, there was only a slight decrease of lactate-dehydrogenase at 4 and 8 weeks after exposure and a slight increase in cathepsin-D and acid phosphatase, none of which were significant.
    a) Increased lactate-dehydrogenase is due to cellular damage or of enzymes in lung lavage fluid is an indicator of toxicity.
    B) PATHOLOGY - Lung specimens from three factory workers exposed to titanium dioxide pigment processing for 9 years were found to contain deposits in pulmonary interstitium with cell destruction and slight fibrosis were seen. Titanium dioxide particles were found in lymph nodes, suggesting clearance through the lymphatic system (Friberg, 1986).
    1) A subsequent report revealed the presence of aluminum and silica in the macrophages, in addition to titanium particles, so the changes may have been due to silica rather than titanium dioxide.
    2) There is experimental evidence that small amounts of quartz added to titanium dioxide were sufficient to produce advanced fibrosis in rats.

Physicochemical

Physical Characteristics

    A) Titanium dioxide, also called titanium oxide, is a white, colorless, tasteless, odorless, amorphous powder which occurs naturally in three crystalline forms: anatase, rutile, and brookite (Weast, 1989; Osol, 1980; HSDB , 1992; Budavari, 1989; Lewis, 1992).
    1) It may be a white to black powder or a crystal. Its natural forms are often red or brown-red due to metal impurities.

Ph

    A) Suspension in water (1:10) is neutral to litmus (HSDB , 1992)

Molecular Weight

    A) 79.90 (Budavari, 1989)

References

General Bibliography

    1) 40 CFR 372.28: Environmental Protection Agency - Toxic Chemical Release Reporting, Community Right-To-Know, Lower thresholds for chemicals of special concern. National Archives and Records Administration (NARA) and the Government Printing Office (GPO). Washington, DC. Final rules current as of Apr 3, 2006.
    2) 40 CFR 372.65: Environmental Protection Agency - Toxic Chemical Release Reporting, Community Right-To-Know, Chemicals and Chemical Categories to which this part applies. National Archives and Records Association (NARA) and the Government Printing Office (GPO), Washington, DC. Final rules current as of Apr 3, 2006.
    3) 49 CFR 172.101 - App. B: Department of Transportation - Table of Hazardous Materials, Appendix B: List of Marine Pollutants. National Archives and Records Administration (NARA) and the Government Printing Office (GPO), Washington, DC. Final rules current as of Aug 29, 2005.
    4) 49 CFR 172.101: Department of Transportation - Table of Hazardous Materials. National Archives and Records Administration (NARA) and the Government Printing Office (GPO), Washington, DC. Final rules current as of Aug 11, 2005.
    5) 62 FR 58840: Notice of the National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances - Proposed AEGL Values, Environmental Protection Agency, NAC/AEGL Committee. National Archives and Records Administration (NARA) and the Government Publishing Office (GPO), Washington, DC, 1997.
    6) 65 FR 14186: Notice of the National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances - Proposed AEGL Values, Environmental Protection Agency, NAC/AEGL Committee. National Archives and Records Administration (NARA) and the Government Publishing Office (GPO), Washington, DC, 2000.
    7) 65 FR 39264: Notice of the National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances - Proposed AEGL Values, Environmental Protection Agency, NAC/AEGL Committee. National Archives and Records Administration (NARA) and the Government Publishing Office (GPO), Washington, DC, 2000.
    8) 65 FR 77866: Notice of the National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances - Proposed AEGL Values, Environmental Protection Agency, NAC/AEGL Committee. National Archives and Records Administration (NARA) and the Government Publishing Office (GPO), Washington, DC, 2000.
    9) 66 FR 21940: Notice of the National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances - Proposed AEGL Values, Environmental Protection Agency, NAC/AEGL Committee. National Archives and Records Administration (NARA) and the Government Publishing Office (GPO), Washington, DC, 2001.
    10) 67 FR 7164: Notice of the National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances - Proposed AEGL Values, Environmental Protection Agency, NAC/AEGL Committee. National Archives and Records Administration (NARA) and the Government Publishing Office (GPO), Washington, DC, 2002.
    11) 68 FR 42710: Notice of the National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances - Proposed AEGL Values, Environmental Protection Agency, NAC/AEGL Committee. National Archives and Records Administration (NARA) and the Government Publishing Office (GPO), Washington, DC, 2003.
    12) 69 FR 54144: Notice of the National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances - Proposed AEGL Values, Environmental Protection Agency, NAC/AEGL Committee. National Archives and Records Administration (NARA) and the Government Publishing Office (GPO), Washington, DC, 2004.
    13) ACGIH: Documentation of the Threshold Limit Values and Biological Exposure Indices, 6th ed, Am Conference of Govt Ind Hyg, Inc, Cincinnati, OH, 1994.
    14) AIHA: 2006 Emergency Response Planning Guidelines and Workplace Environmental Exposure Level Guides Handbook, American Industrial Hygiene Association, Fairfax, VA, 2006.
    15) American Conference of Governmental Industrial Hygienists : ACGIH 2010 Threshold Limit Values (TLVs(R)) for Chemical Substances and Physical Agents and Biological Exposure Indices (BEIs(R)), American Conference of Governmental Industrial Hygienists, Cincinnati, OH, 2010.
    16) Anon: Environmental Health Criteria No 24, World Health Organization, Geneva, Switzerland, 1982.
    17) Bischoff F & Bryson G: Res Commun Chem Pathol Pharmacol 1982; 38:279-290.
    18) Budavari S: The Merck Index, 11th ed, Merck & Co, Inc, Rahway, NJ, 1989, pp 1492.
    19) Burgess JL, Kirk M, Borron SW, et al: Emergency department hazardous materials protocol for contaminated patients. Ann Emerg Med 1999; 34(2):205-212.
    20) Caravati EM: Alkali. In: Dart RC, ed. Medical Toxicology, Lippincott Williams & Wilkins, Philadelphia, PA, 2004.
    21) Chen JL & Fayerweather WE: J Occup Med 1988; 30:937-42.
    22) Clayton GD & Clayton FE: Patty's Industrial Hygiene and Toxicology, Vol 2, Toxicology, 3rd ed, John Wiley & Sons, New York, NY, 1982.
    23) Clayton GD & Clayton FE: Patty's Industrial Hygiene and Toxicology, Volume 2C. Toxicology, 4th ed, John Wiley & Sons, New York, NY, 1994, pp 2276-2285.
    24) DFG: List of MAK and BAT Values 2002, Report No. 38, Deutsche Forschungsgemeinschaft, Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area, Wiley-VCH, Weinheim, Federal Republic of Germany, 2002.
    25) Dragun J: The Soil Chemistry of Hazardous Materials, Hazardous Materials Control Research Institute, Silver Spring, MD, 1988.
    26) Drill VA & Lazar P: Cutaneous Toxicity. Proceedings of the 3rd Conference, 1976, Academic Press, Inc, New York, NY, 1977.
    27) Driscoll KE, Lindenschmidt RC, & Maurer JK: Pulmonary response to inhaled silica or titanium dioxide. Toxicol Appl Pharmacol 1991; 111:201-210.
    28) EPA: Search results for Toxic Substances Control Act (TSCA) Inventory Chemicals. US Environmental Protection Agency, Substance Registry System, U.S. EPA's Office of Pollution Prevention and Toxics. Washington, DC. 2005. Available from URL: http://www.epa.gov/srs/.
    29) ERG: Emergency Response Guidebook. A Guidebook for First Responders During the Initial Phase of a Dangerous Goods/Hazardous Materials Incident, U.S. Department of Transportation, Research and Special Programs Administration, Washington, DC, 2004.
    30) Friberg L, Nordberg GF, & Kessler E: Handbook of the Toxicology of Metals, 2nd ed, I & II, Elsevier Science Publishers BV, Amsterdam, The Netherlands, 1986.
    31) Grant WM: Toxicology of the Eye, 3rd ed, Charles C Thomas, Springfield, IL, 1986, pp 918-919.
    32) HSDB : Hazardous Substances Data Bank. National Library of Medicine. Bethesda, MD (Internet Version). Edition expires 1992; provided by Truven Health Analytics Inc., Greenwood Village, CO.
    33) HSDB : Hazardous Substances Data Bank. National Library of Medicine. Bethesda, MD (Internet Version). Edition expires 1993; provided by Truven Health Analytics Inc., Greenwood Village, CO.
    34) Hathaway GJ, Proctor NH, & Hughes JP: Chemical Hazards of the Workplace, 3rd ed, Van Nostrand Reinhold Company, New York, NY, 1991, pp 545-546.
    35) Hung ST & Mak MKS: Titanium dioxide photocatalysed degradation of organophosphate in a system simulating the natural aquatic environment. Environ Technol 1993; 14:265-269.
    36) IARC Working Group on the Evaluation of Carcinogenic Risks to Humans : IARC Monographs on the Evaluation of Carcinogenic Risks to Humans: 1,3-Butadiene, Ethylene Oxide and Vinyl Halides (Vinyl Fluoride, Vinyl Chloride and Vinyl Bromide), 97, International Agency for Research on Cancer, Lyon, France, 2008.
    37) IARC Working Group on the Evaluation of Carcinogenic Risks to Humans : IARC Monographs on the Evaluation of Carcinogenic Risks to Humans: Formaldehyde, 2-Butoxyethanol and 1-tert-Butoxypropan-2-ol, 88, International Agency for Research on Cancer, Lyon, France, 2006.
    38) IARC Working Group on the Evaluation of Carcinogenic Risks to Humans : IARC Monographs on the Evaluation of Carcinogenic Risks to Humans: Household Use of Solid Fuels and High-temperature Frying, 95, International Agency for Research on Cancer, Lyon, France, 2010a.
    39) IARC Working Group on the Evaluation of Carcinogenic Risks to Humans : IARC Monographs on the Evaluation of Carcinogenic Risks to Humans: Smokeless Tobacco and Some Tobacco-specific N-Nitrosamines, 89, International Agency for Research on Cancer, Lyon, France, 2007.
    40) IARC Working Group on the Evaluation of Carcinogenic Risks to Humans : IARC Monographs on the Evaluation of Carcinogenic Risks to Humans: Some Non-heterocyclic Polycyclic Aromatic Hydrocarbons and Some Related Exposures, 92, International Agency for Research on Cancer, Lyon, France, 2010.
    41) IARC: List of all agents, mixtures and exposures evaluated to date - IARC Monographs: Overall Evaluations of Carcinogenicity to Humans, Volumes 1-88, 1972-PRESENT. World Health Organization, International Agency for Research on Cancer. Lyon, FranceAvailable from URL: http://monographs.iarc.fr/monoeval/crthall.html. As accessed Oct 07, 2004.
    42) ICAO: Technical Instructions for the Safe Transport of Dangerous Goods by Air, 2003-2004. International Civil Aviation Organization, Montreal, Quebec, Canada, 2002.
    43) ILO: Encyclopaedia of Occupational Health and Safety, 3rd ed, 2, International Labour Organization, Geneva, Switzerland, 1983.
    44) ITI: Toxic and Hazarous Industrial Chemicals Safety Manual, The International Technical Information Institute, Tokyo, Japan, 1988.
    45) International Agency for Research on Cancer (IARC): IARC monographs on the evaluation of carcinogenic risks to humans: list of classifications, volumes 1-116. International Agency for Research on Cancer (IARC). Lyon, France. 2016. Available from URL: http://monographs.iarc.fr/ENG/Classification/latest_classif.php. As accessed 2016-08-24.
    46) International Agency for Research on Cancer: IARC Monographs on the Evaluation of Carcinogenic Risks to Humans. World Health Organization. Geneva, Switzerland. 2015. Available from URL: http://monographs.iarc.fr/ENG/Classification/. As accessed 2015-08-06.
    47) Kanematsu: Mutat Res 1980; 77:109-116.
    48) Lee KP: Toxicol Appl Pharmacol 1985; 79:179-192.
    49) Lefevre MJ: First Aid Manual for Chemical Accidents, 2nd ed, Van Nostrand Reinhold Company, New York, NY, 1989.
    50) Lewis RJ: Dangerous Properties of Industrial Materials, 8th ed, Van Nostrand Reinhold Company, New York, NY, 1992, pp 3301-3302.
    51) Lewis RJ: Hawley's Condensed Chemical Dictionary, 12th ed, Van Nostrand Reinhold Company, New York, NY, 1993.
    52) Mickiewicz L: Med Pr 1984; 35:209-215.
    53) Miller BM, Pujadas E, & Gocke E: Evaluation of the micronucleus test in vitro using Chinese hamster cells - results of four chemicals weakly positive in the in vivo micronucleus test. Environ Molec Mutagen 1995; 26:240-247.
    54) NCI: Bioassay of Titanium Dioxide for Possible Carcinogenicity. Dhew (NIH) Pub No 78-1347, National Cancer Institute, Bethesda, MD, 1978.
    55) NFPA: Fire Protection Guide to Hazardous Materials, 10th ed, National Fire Protection Association, Quincy, MA, 1991.
    56) NFPA: Fire Protection Guide to Hazardous Materials, 13th ed., National Fire Protection Association, Quincy, MA, 2002.
    57) NRC: Acute Exposure Guideline Levels for Selected Airborne Chemicals - Volume 1, Subcommittee on Acute Exposure Guideline Levels, Committee on Toxicology, Board on Environmental Studies and Toxicology, Commission of Life Sciences, National Research Council. National Academy Press, Washington, DC, 2001.
    58) NRC: Acute Exposure Guideline Levels for Selected Airborne Chemicals - Volume 2, Subcommittee on Acute Exposure Guideline Levels, Committee on Toxicology, Board on Environmental Studies and Toxicology, Commission of Life Sciences, National Research Council. National Academy Press, Washington, DC, 2002.
    59) NRC: Acute Exposure Guideline Levels for Selected Airborne Chemicals - Volume 3, Subcommittee on Acute Exposure Guideline Levels, Committee on Toxicology, Board on Environmental Studies and Toxicology, Commission of Life Sciences, National Research Council. National Academy Press, Washington, DC, 2003.
    60) NRC: Acute Exposure Guideline Levels for Selected Airborne Chemicals - Volume 4, Subcommittee on Acute Exposure Guideline Levels, Committee on Toxicology, Board on Environmental Studies and Toxicology, Commission of Life Sciences, National Research Council. National Academy Press, Washington, DC, 2004.
    61) Naradzay J & Barish RA: Approach to ophthalmologic emergencies. Med Clin North Am 2006; 90(2):305-328.
    62) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for 1,2,3-Trimethylbenzene (Proposed). United States Environmental Protection Agency. Washington, DC. 2006k. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020d68a&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    63) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for 1,2,4-Trimethylbenzene (Proposed). United States Environmental Protection Agency. Washington, DC. 2006m. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020d68a&disposition=attachment&contentType=pdf. As accessed 2010-08-16.
    64) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for 1,2-Butylene Oxide (Proposed). United States Environmental Protection Agency. Washington, DC. 2008d. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648083cdbb&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    65) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for 1,2-Dibromoethane (Proposed). United States Environmental Protection Agency. Washington, DC. 2007g. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=09000064802796db&disposition=attachment&contentType=pdf. As accessed 2010-08-18.
    66) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for 1,3,5-Trimethylbenzene (Proposed). United States Environmental Protection Agency. Washington, DC. 2006l. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020d68a&disposition=attachment&contentType=pdf. As accessed 2010-08-16.
    67) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for 2-Ethylhexyl Chloroformate (Proposed). United States Environmental Protection Agency. Washington, DC. 2007b. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648037904e&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    68) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Acrylonitrile (Proposed). United States Environmental Protection Agency. Washington, DC. 2007c. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648028e6a3&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    69) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Adamsite (Proposed). United States Environmental Protection Agency. Washington, DC. 2007h. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020fd29&disposition=attachment&contentType=pdf. As accessed 2010-08-16.
    70) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Agent BZ (3-quinuclidinyl benzilate) (Proposed). United States Environmental Protection Agency. Washington, DC. 2007f. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=09000064803ad507&disposition=attachment&contentType=pdf. As accessed 2010-08-18.
    71) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Allyl Chloride (Proposed). United States Environmental Protection Agency. Washington, DC. 2008. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648039d9ee&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    72) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Aluminum Phosphide (Proposed). United States Environmental Protection Agency. Washington, DC. 2005b. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020c5ed&disposition=attachment&contentType=pdf. As accessed 2010-08-16.
    73) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Arsenic Trioxide (Proposed). United States Environmental Protection Agency. Washington, DC. 2007m. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=0900006480220305&disposition=attachment&contentType=pdf. As accessed 2010-08-16.
    74) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Automotive Gasoline Unleaded (Proposed). United States Environmental Protection Agency. Washington, DC. 2009a. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=0900006480a7cc17&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    75) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Biphenyl (Proposed). United States Environmental Protection Agency. Washington, DC. 2005j. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=09000064801ea1b7&disposition=attachment&contentType=pdf. As accessed 2010-08-16.
    76) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Bis-Chloromethyl Ether (BCME) (Proposed). United States Environmental Protection Agency. Washington, DC. 2006n. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648022db11&disposition=attachment&contentType=pdf. As accessed 2010-08-16.
    77) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Boron Tribromide (Proposed). United States Environmental Protection Agency. Washington, DC. 2008a. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=09000064803ae1d3&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    78) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Bromine Chloride (Proposed). United States Environmental Protection Agency. Washington, DC. 2007d. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648039732a&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    79) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Bromoacetone (Proposed). United States Environmental Protection Agency. Washington, DC. 2008e. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=09000064809187bf&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    80) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Calcium Phosphide (Proposed). United States Environmental Protection Agency. Washington, DC. 2005d. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020c5ed&disposition=attachment&contentType=pdf. As accessed 2010-08-16.
    81) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Carbonyl Fluoride (Proposed). United States Environmental Protection Agency. Washington, DC. 2008b. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=09000064803ae328&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    82) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Carbonyl Sulfide (Proposed). United States Environmental Protection Agency. Washington, DC. 2007e. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648037ff26&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    83) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Chlorobenzene (Proposed). United States Environmental Protection Agency. Washington, DC. 2008c. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=09000064803a52bb&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    84) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Cyanogen (Proposed). United States Environmental Protection Agency. Washington, DC. 2008f. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=09000064809187fe&disposition=attachment&contentType=pdf. As accessed 2010-08-15.
    85) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Dimethyl Phosphite (Proposed). United States Environmental Protection Agency. Washington, DC. 2009. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=0900006480a7cbf3&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    86) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Diphenylchloroarsine (Proposed). United States Environmental Protection Agency. Washington, DC. 2007l. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020fd29&disposition=attachment&contentType=pdf. As accessed 2010-08-16.
    87) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Ethyl Isocyanate (Proposed). United States Environmental Protection Agency. Washington, DC. 2008h. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648091884e&disposition=attachment&contentType=pdf. As accessed 2010-08-15.
    88) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Ethyl Phosphorodichloridate (Proposed). United States Environmental Protection Agency. Washington, DC. 2008i. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=0900006480920347&disposition=attachment&contentType=pdf. As accessed 2010-08-15.
    89) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Ethylbenzene (Proposed). United States Environmental Protection Agency. Washington, DC. 2008g. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=09000064809203e7&disposition=attachment&contentType=pdf. As accessed 2010-08-15.
    90) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Ethyldichloroarsine (Proposed). United States Environmental Protection Agency. Washington, DC. 2007j. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020fd29&disposition=attachment&contentType=pdf. As accessed 2010-08-16.
    91) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Germane (Proposed). United States Environmental Protection Agency. Washington, DC. 2008j. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=0900006480963906&disposition=attachment&contentType=pdf. As accessed 2010-08-15.
    92) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Hexafluoropropylene (Proposed). United States Environmental Protection Agency. Washington, DC. 2006. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=09000064801ea1f5&disposition=attachment&contentType=pdf. As accessed 2010-08-15.
    93) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Ketene (Proposed). United States Environmental Protection Agency. Washington, DC. 2007. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020ee7c&disposition=attachment&contentType=pdf. As accessed 2010-08-15.
    94) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Magnesium Aluminum Phosphide (Proposed). United States Environmental Protection Agency. Washington, DC. 2005h. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020c5ed&disposition=attachment&contentType=pdf. As accessed 2010-08-16.
    95) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Magnesium Phosphide (Proposed). United States Environmental Protection Agency. Washington, DC. 2005g. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020c5ed&disposition=attachment&contentType=pdf. As accessed 2010-08-16.
    96) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Malathion (Proposed). United States Environmental Protection Agency. Washington, DC. 2009k. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=09000064809639df&disposition=attachment&contentType=pdf. As accessed 2010-08-15.
    97) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Mercury Vapor (Proposed). United States Environmental Protection Agency. Washington, DC. 2009b. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=0900006480a8a087&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    98) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Methyl Isothiocyanate (Proposed). United States Environmental Protection Agency. Washington, DC. 2008k. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=0900006480963a03&disposition=attachment&contentType=pdf. As accessed 2010-08-15.
    99) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Methyl Parathion (Proposed). United States Environmental Protection Agency. Washington, DC. 2008l. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=0900006480963a57&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    100) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Methyl tertiary-butyl ether (Proposed). United States Environmental Protection Agency. Washington, DC. 2007a. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=09000064802a4985&disposition=attachment&contentType=pdf. As accessed 2010-08-15.
    101) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Methylchlorosilane (Proposed). United States Environmental Protection Agency. Washington, DC. 2005. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020c5f4&disposition=attachment&contentType=pdf. As accessed 2010-08-15.
    102) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Methyldichloroarsine (Proposed). United States Environmental Protection Agency. Washington, DC. 2007i. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020fd29&disposition=attachment&contentType=pdf. As accessed 2010-08-16.
    103) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Methyldichlorosilane (Proposed). United States Environmental Protection Agency. Washington, DC. 2005a. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020c646&disposition=attachment&contentType=pdf. As accessed 2010-08-15.
    104) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Nitrogen Mustard (HN1 CAS Reg. No. 538-07-8) (Proposed). United States Environmental Protection Agency. Washington, DC. 2006a. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020d6cb&disposition=attachment&contentType=pdf. As accessed 2010-08-15.
    105) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Nitrogen Mustard (HN2 CAS Reg. No. 51-75-2) (Proposed). United States Environmental Protection Agency. Washington, DC. 2006b. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020d6cb&disposition=attachment&contentType=pdf. As accessed 2010-08-15.
    106) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Nitrogen Mustard (HN3 CAS Reg. No. 555-77-1) (Proposed). United States Environmental Protection Agency. Washington, DC. 2006c. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020d6cb&disposition=attachment&contentType=pdf. As accessed 2010-08-15.
    107) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Nitrogen Tetroxide (Proposed). United States Environmental Protection Agency. Washington, DC. 2008n. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648091855b&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    108) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Nitrogen Trifluoride (Proposed). United States Environmental Protection Agency. Washington, DC. 2009l. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=0900006480963e0c&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    109) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Parathion (Proposed). United States Environmental Protection Agency. Washington, DC. 2008o. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=0900006480963e32&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    110) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Perchloryl Fluoride (Proposed). United States Environmental Protection Agency. Washington, DC. 2009c. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=0900006480a7e268&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    111) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Perfluoroisobutylene (Proposed). United States Environmental Protection Agency. Washington, DC. 2009d. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=0900006480a7e26a&disposition=attachment&contentType=pdf. As accessed 2010-08-15.
    112) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Phenyl Isocyanate (Proposed). United States Environmental Protection Agency. Washington, DC. 2008p. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648096dd58&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    113) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Phenyl Mercaptan (Proposed). United States Environmental Protection Agency. Washington, DC. 2006d. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020cc0c&disposition=attachment&contentType=pdf. As accessed 2010-08-16.
    114) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Phenyldichloroarsine (Proposed). United States Environmental Protection Agency. Washington, DC. 2007k. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020fd29&disposition=attachment&contentType=pdf. As accessed 2010-08-16.
    115) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Phorate (Proposed). United States Environmental Protection Agency. Washington, DC. 2008q. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648096dcc8&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    116) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Phosgene (Draft-Revised). United States Environmental Protection Agency. Washington, DC. 2009e. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=0900006480a8a08a&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    117) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Phosgene Oxime (Proposed). United States Environmental Protection Agency. Washington, DC. 2009f. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=0900006480a7e26d&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    118) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Potassium Cyanide (Proposed). United States Environmental Protection Agency. Washington, DC. 2009g. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=0900006480a7cbb9&disposition=attachment&contentType=pdf. As accessed 2010-08-15.
    119) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Potassium Phosphide (Proposed). United States Environmental Protection Agency. Washington, DC. 2005c. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020c5ed&disposition=attachment&contentType=pdf. As accessed 2010-08-16.
    120) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Propargyl Alcohol (Proposed). United States Environmental Protection Agency. Washington, DC. 2006e. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020ec91&disposition=attachment&contentType=pdf. As accessed 2010-08-16.
    121) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Selenium Hexafluoride (Proposed). United States Environmental Protection Agency. Washington, DC. 2006f. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020ec55&disposition=attachment&contentType=pdf. As accessed 2010-08-16.
    122) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Silane (Proposed). United States Environmental Protection Agency. Washington, DC. 2006g. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020d523&disposition=attachment&contentType=pdf. As accessed 2010-08-16.
    123) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Sodium Cyanide (Proposed). United States Environmental Protection Agency. Washington, DC. 2009h. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=0900006480a7cbb9&disposition=attachment&contentType=pdf. As accessed 2010-08-15.
    124) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Sodium Phosphide (Proposed). United States Environmental Protection Agency. Washington, DC. 2005i. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020c5ed&disposition=attachment&contentType=pdf. As accessed 2010-08-16.
    125) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Strontium Phosphide (Proposed). United States Environmental Protection Agency. Washington, DC. 2005f. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020c5ed&disposition=attachment&contentType=pdf. As accessed 2010-08-16.
    126) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Sulfuryl Chloride (Proposed). United States Environmental Protection Agency. Washington, DC. 2006h. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020ec7a&disposition=attachment&contentType=pdf. As accessed 2010-08-16.
    127) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Tear Gas (Proposed). United States Environmental Protection Agency. Washington, DC. 2008s. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648096e551&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    128) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Tellurium Hexafluoride (Proposed). United States Environmental Protection Agency. Washington, DC. 2009i. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=0900006480a7e2a1&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    129) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Tert-Octyl Mercaptan (Proposed). United States Environmental Protection Agency. Washington, DC. 2008r. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648096e5c7&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    130) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Tetramethoxysilane (Proposed). United States Environmental Protection Agency. Washington, DC. 2006j. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020d632&disposition=attachment&contentType=pdf. As accessed 2010-08-17.
    131) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Trimethoxysilane (Proposed). United States Environmental Protection Agency. Washington, DC. 2006i. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020d632&disposition=attachment&contentType=pdf. As accessed 2010-08-16.
    132) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Trimethyl Phosphite (Proposed). United States Environmental Protection Agency. Washington, DC. 2009j. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=0900006480a7d608&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    133) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Trimethylacetyl Chloride (Proposed). United States Environmental Protection Agency. Washington, DC. 2008t. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648096e5cc&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    134) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for Zinc Phosphide (Proposed). United States Environmental Protection Agency. Washington, DC. 2005e. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020c5ed&disposition=attachment&contentType=pdf. As accessed 2010-08-16.
    135) National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances: Acute Exposure Guideline Levels (AEGLs) for n-Butyl Isocyanate (Proposed). United States Environmental Protection Agency. Washington, DC. 2008m. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=09000064808f9591&disposition=attachment&contentType=pdf. As accessed 2010-08-12.
    136) National Heart,Lung,and Blood Institute: Expert panel report 3: guidelines for the diagnosis and management of asthma. National Heart,Lung,and Blood Institute. Bethesda, MD. 2007. Available from URL: http://www.nhlbi.nih.gov/guidelines/asthma/asthgdln.pdf.
    137) National Institute for Occupational Safety and Health: NIOSH Pocket Guide to Chemical Hazards, U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, Cincinnati, OH, 2007.
    138) National Research Council : Acute exposure guideline levels for selected airborne chemicals, 5, National Academies Press, Washington, DC, 2007.
    139) National Research Council: Acute exposure guideline levels for selected airborne chemicals, 6, National Academies Press, Washington, DC, 2008.
    140) National Research Council: Acute exposure guideline levels for selected airborne chemicals, 7, National Academies Press, Washington, DC, 2009.
    141) National Research Council: Acute exposure guideline levels for selected airborne chemicals, 8, National Academies Press, Washington, DC, 2010.
    142) OHM/TADS : Oil and Hazardous Materials/Technical Assistance Data System. US Environmental Protection Agency. Washington, DC (Internet Version). Edition expires 1992; provided by Truven Health Analytics Inc., Greenwood Village, CO.
    143) OHM/TADS : Oil and Hazardous Materials/Technical Assistance Data System. US Environmental Protection Agency. Washington, DC (Internet Version). Edition expires 1994; provided by Truven Health Analytics Inc., Greenwood Village, CO.
    144) OSHA: OSHA Regulated Hazardous Substances: Industrial Exposure and Control Technologies, Government Institutes, Inc, Rockville, MD, 1990.
    145) Oleru UG: Am J Ind Med 1987; 12:173-80.
    146) Osol A: Remington's Pharmaceutical Sciences, 16th ed, Mack Publishing Co, Easton, PA, 1980.
    147) Otani N, Ishimatsu S, & Mochizuki T: Acute group poisoning by titanium dioxide: inhalation exposure may cause metal fume fever. Am J Emerg Med 2008; 26(5):608-611.
    148) Peate WF: Work-related eye injuries and illnesses. Am Fam Physician 2007; 75(7):1017-1022.
    149) Sax NI & Lewis RJ: Hawley's Condensed Chemical Dictionary, 11th ed, Van Nostrand Reinhold Company, New York, NY, 1987, pp 1159.
    150) Siemiatycki J, Dewar R, & Nadon L: Occupational risk factors for bladder cancer: results from a case-control study in Montreal, Quebec, Canada. Am J Epidemiol 1994; 140:1061-1080.
    151) Sjostrand M & Rylander R: Environ Res 1984; 33:307-311.
    152) U.S. Department of Energy, Office of Emergency Management: Protective Action Criteria (PAC) with AEGLs, ERPGs, & TEELs: Rev. 26 for chemicals of concern. U.S. Department of Energy, Office of Emergency Management. Washington, DC. 2010. Available from URL: http://www.hss.doe.gov/HealthSafety/WSHP/Chem_Safety/teel.html. As accessed 2011-06-27.
    153) U.S. Department of Health and Human Services, Public Health Service, National Toxicology Project : 11th Report on Carcinogens. U.S. Department of Health and Human Services, Public Health Service, National Toxicology Program. Washington, DC. 2005. Available from URL: http://ntp.niehs.nih.gov/INDEXA5E1.HTM?objectid=32BA9724-F1F6-975E-7FCE50709CB4C932. As accessed 2011-06-27.
    154) U.S. Environmental Protection Agency: Discarded commercial chemical products, off-specification species, container residues, and spill residues thereof. Environmental Protection Agency's (EPA) Resource Conservation and Recovery Act (RCRA); List of hazardous substances and reportable quantities 2010b; 40CFR(261.33, e-f):77-.
    155) U.S. Environmental Protection Agency: Integrated Risk Information System (IRIS). U.S. Environmental Protection Agency. Washington, DC. 2011. Available from URL: http://cfpub.epa.gov/ncea/iris/index.cfm?fuseaction=iris.showSubstanceList&list_type=date. As accessed 2011-06-21.
    156) U.S. Environmental Protection Agency: List of Radionuclides. U.S. Environmental Protection Agency. Washington, DC. 2010a. Available from URL: http://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol27/pdf/CFR-2010-title40-vol27-sec302-4.pdf. As accessed 2011-06-17.
    157) U.S. Environmental Protection Agency: List of hazardous substances and reportable quantities. U.S. Environmental Protection Agency. Washington, DC. 2010. Available from URL: http://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol27/pdf/CFR-2010-title40-vol27-sec302-4.pdf. As accessed 2011-06-17.
    158) U.S. Environmental Protection Agency: The list of extremely hazardous substances and their threshold planning quantities (CAS Number Order). U.S. Environmental Protection Agency. Washington, DC. 2010c. Available from URL: http://www.gpo.gov/fdsys/pkg/CFR-2010-title40-vol27/pdf/CFR-2010-title40-vol27-part355.pdf. As accessed 2011-06-17.
    159) U.S. Occupational Safety and Health Administration: Part 1910 - Occupational safety and health standards (continued) Occupational Safety, and Health Administration's (OSHA) list of highly hazardous chemicals, toxics and reactives. Subpart Z - toxic and hazardous substances. CFR 2010 2010; Vol6(SEC1910):7-.
    160) U.S. Occupational Safety, and Health Administration (OSHA): Process safety management of highly hazardous chemicals. 29 CFR 2010 2010; 29(1910.119):348-.
    161) United States Environmental Protection Agency Office of Pollution Prevention and Toxics: Acute Exposure Guideline Levels (AEGLs) for Vinyl Acetate (Proposed). United States Environmental Protection Agency. Washington, DC. 2006. Available from URL: http://www.regulations.gov/search/Regs/contentStreamer?objectId=090000648020d6af&disposition=attachment&contentType=pdf. As accessed 2010-08-16.
    162) Venugopal B & Luckey TD: Metal Toxicity in Mammals, 2, Plenum Press, New York, NY, 1978.
    163) Weast RC: Handbook of Chemistry and Physics, 69th ed, CRC Press Inc, Boca Raton, FL, 1989.