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CHROMIUM

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Classification   |    Detailed evidence-based information

Substances Included Synonyms

Therapeutic Toxic Class

    A) Chromium is a metallic transition element found in nature as chromite. Chromite ore is reduced with aluminum, carbon, or silicon and then purified to make chromium metal.

Specific Substances

    A) No Synonyms were found in group or single elements
    1.2.1) MOLECULAR FORMULA
    1) Cr (Element)

Available Forms Sources

    A) FORMS
    1) Chromium is a lustrous, steel-gray metal (Budavari, 2000; Sittig, 1991).
    2) Chromium metal is brittle, hard, lustrous, and odorless. It is blue-white to steel gray in color (Ashford, 1994; NIOSH , 2002).
    3) Chromium metal is difficult to work with. At low temperatures it is brittle. Using it in casts requires melting which requires very high temperatures (Bingham et al, 2001).
    4) Chromium is a brittle, hard, semigray metal. Its name was derived from the Greek word for color (Lewis, 1997).
    5) Metallic chromium can be purchased as granules, lumps, and powder. Chromium powder and crystals can be as high as 99.97% pure (Lewis, 1997).
    6) Aluminothermic, ductile, and electrolytic chromium are available in the United States (HSDB , 2002).
    7) Chromium metals and alloys, including chromium metal, stainless steels, and other chromium-containing alloys, generally have a low order of toxicity compared to other valence forms (ACGIH, 1991). Chromium has 4 common isotopes: Cr(50), Cr(52), Cr(53), and Cr(54) (Kirk-Othmer, 1992).
    B) SOURCES
    1) Elemental chromium does not occur naturally (ATSDR, 1993).
    2) Chromite ore is reduced with aluminum, carbon, or silicon and then purified to make chromium metal. However, chromite ore is no longer mined in the United States. It is imported from South Africa, Turkey, and Zimbabwe (ATSDR, 1993).
    3) Chromium exists naturally in the atmosphere as a result of continental dust flux, and volcanic dust and gas flux (ATSDR, 1993).
    4) Man releases chromium into the atmosphere by burning natural gas, coal, oil, municipal wastes, and sewage sludge. Fugitive emissions from road dusts, wear and tear of asbestos brake linings, and vehicle catalytic converters are additional sources of atmospheric chromium (ATSDR, 1993).
    5) Chromium is a metallic transition element found in nature as chromite (Lewis, 1998).
    6) Chromium metal is made using a reduction process involving aluminum and chromium oxides. The Symplex process, involving chromium oxide and metallurgical coke may also be used. A third process, called the Elkem process, uses ferrochrome, sulfuric acid, and ammonium sulfate (Ashford, 1994).
    7) Metallic chromium has been detected in cigarette smoke. The amount of chromium found depends on the soil conditions where the tobacco was grown and proximity of tobacco farms to refineries (Clayton & Clayton, 1993).
    8) Chromium metal does not occur naturally. However, it can be derived from chromite, a chromium ore. In the Earth's crust the chromium concentration is 0.1 to 0.3 ppm (Bingham et al, 2001).
    9) Chromium's abundance in the earth's crust ranges from 100 to 300 ppm (Budavari, 1996).
    10) Chromium is typically found in concentrations of 5.0 to 3000 ppm in native soil. Its lowest native soil concentration is approximately 0.5 ppm and its highest is 10,000 ppm (Dragun, 1988).
    11) Groundwater typically contains less than 1.0 to 5.0 ppm of chromium (Dragun, 1988).
    12) Elemental chromium is not found naturally. It can be derived from spinel ore, chromite, or ferrous chromite, all of which are widely distributed across the earth's surface (ILO, 1998).
    13) Chromium metal can be made from chromium oxide (ILO, 1998).
    14) Chromium metal can be made by reducing chromite directly, by using finely divided aluminum or carbon to reduce chromium oxide, and by electrolysis of chromium solutions (Lewis, 1997).
    C) USES
    1) Chromium is used to make stainless steel, alloy cast iron, nonferrous alloys, among other miscellaneous materials. It is also used in heat resistant bricks that line high temperature industrial furnaces (Budavari, 2000)
    2) Pure chromium is used mainly in equipment electroplating processes, including manufacture of automobile parts and electric equipment. It may also be combined with cobalt, copper, iron, nickel, niobium, titanium, and other metals to make alloys (ILO, 1998).
    3) Pure chromium metal is used in creep resistant, high temperature alloys. It is also used as a refractory oxide, and in magnetite and magnetite-chromate refractory compositions (ILO, 1998).
    4) Electroplating metals with chromium adds hardness and corrosion resistance (Lewis, 1998).
    5) Chromium metal is used to increase the durability and corrosion resistance of metals. It is also used for chrome plating (Sittig, 1991).
    6) Chromium metal is used to make alloys, such as cobalt-chromium stellite, cobalt-chromium tungsten, and nickel chromium. In turn, these are used to make extrusion dies, turbine blades, valve seats, cemented carbide cutting tools, jet engine parts, and electrical heating elements (Ashford, 1994).
    7) Chromium is used in nuclear and high-temperature research (Lewis, 1997).
    8) Chromium is used widely in chrome-steel, chrome-nickel-steel (stainless steel), cobalt-chromium stellite, and cobalt-chromium-tungsten alloys, and in chrome plating for greatly increasing the corrosion resistance and durability of metals. It is also used over plastic substrates and automotive accessories as a protective corrosion-resistant coating (Budavari, 2000; Ashford, 1994; Lewis, 1993).
    9) Metal surface treatments and corrosion controls account for 25 percent of its use (Zenz, 1994).
    10) It is used in the leather tanning and textile industries, in refractory products, in photographic fixing baths, in industrial water treatment systems, in catalysts for halogenation, alkylation, and catalytic cracking of hydrocarbons, in fuel and propellant additives, in ceramics, in toners for copiers, in magnetic tapes, and as a chemical intermediate (Bingham et al, 2001; Hathaway et al, 1996; HSDB , 2002).

Overview

Life Support

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

Clinical Effects

    0.2.1) SUMMARY OF EXPOSURE
    A) Chromium metal is considered to be relatively nontoxic. Also, there is little evidence of substantial toxicity from chromic (chromium III) or chromous (chromium II) salts, probably because of poor penetration of skin and mucous membranes. Chromium is an essential nutrient that is necessary for normal glucose tolerance.
    0.2.4) HEENT
    A) Chromium particles can cause eye irritation.
    0.2.6) RESPIRATORY
    A) Pulmonary fibrosis and bronchial asthma may occur.
    0.2.14) DERMATOLOGIC
    A) Non-healing dermatitis and cutaneous granuloma have occurred in patients treated with orthopedic internal fixation devices, containing chromium and other metals.
    0.2.19) IMMUNOLOGIC
    A) No evidence for an association between the use of chromium in dental materials and chromate allergy has been found.
    0.2.20) REPRODUCTIVE
    A) 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) ACGIH has has classified metallic chromium as A4 (not classifiable as a human carcinogen).
    B) There is no evidence that exposure to trivalent chromium salts causes cancer in man. Soluble hexavalent chromates are considered human carcinogens, and insoluble chromates such as stainless steel welding fumes have been linked with increased risk for human lung cancer.

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.

Treatment Overview

    0.4.5) DERMAL EXPOSURE
    A) OVERVIEW
    1) Treatment is symptomatic and supportive.

Range Of Toxicity

    A) The minimum lethal human dose to this agent has not been delineated. Alloy steel plant workers exposed to 0.61 mg Cr (0)/ m(3) for an average of 7 years were found to have normal levels of urinary proteins and enzymes.

Clinical Effects

Summary Of Exposure

    A) Chromium metal is considered to be relatively nontoxic. Also, there is little evidence of substantial toxicity from chromic (chromium III) or chromous (chromium II) salts, probably because of poor penetration of skin and mucous membranes. Chromium is an essential nutrient that is necessary for normal glucose tolerance.

Heent

    3.4.1) SUMMARY
    A) Chromium particles can cause eye irritation.
    3.4.3) EYES
    A) Chromium particles can cause eye irritation (Sittig, 1991).

Respiratory

    3.6.1) SUMMARY
    A) Pulmonary fibrosis and bronchial asthma may occur.
    3.6.2) CLINICAL EFFECTS
    A) FIBROSIS OF LUNG
    1) PNEUMOCONIOSIS - Spotty, moderately severe non-nodular pneumoconiosis has been described (Taylor & Davies, 1977).
    2) Inhalation has an irritant effect in the lower respiratory tract and may result in pulmonary fibrosis and emphysema (Dingle, 1992).

Dermatologic

    3.14.1) SUMMARY
    A) Non-healing dermatitis and cutaneous granuloma have occurred in patients treated with orthopedic internal fixation devices, containing chromium and other metals.
    3.14.2) CLINICAL EFFECTS
    A) HYPERSENSITIVITY REACTION
    1) Non-healing dermatitis and cutaneous granuloma have occurred in patients treated with orthopedic internal fixation devices, containing chromium and other metals. These lesions resolved only after removal of the prostheses (Macias & Palacios, 1986; Rostoker et al, 1987; Thomas et al, 1987).
    B) CHEMICAL BURN
    1) Systemic symptoms and death have occurred after external burns, with a delay of onset of GI symptoms of hours or days. Burns initially resemble first and second degree burns, but extend to subcutaneous tissue within a couple of days (Kelly et al, 1982; Schiffl et al, 1982).

Musculoskeletal

    3.15.2) CLINICAL EFFECTS
    A) INCREASED MUSCLE TONE
    1) Muscle cramps may be noted (Wang et al, 1985).

Immunologic

    3.19.1) SUMMARY
    A) No evidence for an association between the use of chromium in dental materials and chromate allergy has been found.
    3.19.2) CLINICAL EFFECTS
    A) IMMUNE SYSTEM FINDING
    1) LACK OF EFFECT
    a) DENTAL MATERIALS - No evidence for an association between the use of chromium in dental materials and chromate allergy has been found (Yontchev et al, 1986; Burrows, 1986).

Reproductive

    3.20.1) SUMMARY
    A) 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) ANIMAL STUDIES
    1) Injected chromium trioxide caused birth defects and resorptions in hamsters (Gale, 1974; Gale & Bunch, 1979). Chromium chloride and trioxide were teratogenic in mice (Iijima, 1975; Iijima, 1979). Sodium dichromate was mildly teratogenic in chickens (Ridgway & Karnofsky, 1952).
    3.20.3) EFFECTS IN PREGNANCY
    A) ANIMAL STUDIES
    1) Transplacental transfer of chromium chloride has been shown in mice (Friberg et al, 1986), and chromium levels in the human fetus are ten times those found in adults (HSDB , 2002). The embryonic and fetal uptake of chromate was ten times greater than that of trivalent chromium in rats (Friberg et al, 1986).

Carcinogenicity

    3.21.1) IARC CATEGORY
    A) IARC Carcinogenicity Ratings for CAS7440-47-3 (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: Chromium, metallic
    b) Carcinogen Rating: 3
    1) The agent (mixture or exposure circumstance) is not classifiable as to its carcinogenicity to humans. This category is used most commonly for agents, mixtures and exposure circumstances for which the evidence of carcinogenicity is inadequate in humans and inadequate or limited in experimental animals. Exceptionally, agents (mixtures) for which the evidence of carcinogenicity is inadequate in humans but sufficient in experimental animals may be placed in this category when there is strong evidence that the mechanism of carcinogenicity in experimental animals does not operate in humans. Agents, mixtures and exposure circumstances that do not fall into any other group are also placed in this category.
    2) IARC Classification
    a) Listed as: Chromium VI compounds
    b) Carcinogen Rating: 1
    1) The agent (mixture) is carcinogenic to humans. The exposure circumstance entails exposures that are carcinogenic to humans. This category is used when there is sufficient evidence of carcinogenicity in humans. Exceptionally, an agent (mixture) may be placed in this category when evidence of carcinogenicity in humans is less than sufficient but there is sufficient evidence of carcinogenicity in experimental animals and strong evidence in exposed humans that the agent (mixture) acts through a relevant mechanism of carcinogenicity.
    3.21.2) SUMMARY/HUMAN
    A) ACGIH has has classified metallic chromium as A4 (not classifiable as a human carcinogen).
    B) There is no evidence that exposure to trivalent chromium salts causes cancer in man. Soluble hexavalent chromates are considered human carcinogens, and insoluble chromates such as stainless steel welding fumes have been linked with increased risk for human lung cancer.
    3.21.3) HUMAN STUDIES
    A) LUNG CANCER
    1) Increased incidence of LUNG CANCER among workers in the manufacture of chrome pigments has been reported in Germany, Norway, Canada, and the United States (ACGIH, 1996a; (HSDB , 2002). Exposures were generally mixed, involving both trivalent and hexavalent chromium compounds. Relative risk for lung cancer has been in the range of 3- to 50-fold, with a latent period of as much as 36 years (Clayton & Clayton, 1994). An increased incidence of lung cancer was reported in a study of workers exposed to chromium while working in the ferrochromium industry in Slovakia. No significant effect from smoking was found in this study (Halasova et al, 2005).
    2) In a retrospective mortality study of employees at the largest chromate manufacturing site in the USA, a subgroup with previous high-level exposure at another older site had an elevated risk of cancer (odds ratio = 1.22 for each 3 years of high-level exposure). Employees who had worked exclusively at the newer facility did not have an increased incidence of cancer deaths (Pastides et al, 1994).
    3) Risk of lung cancer mortality for former chromate production workers was elevated, and increased with increasing duration of employment and latency since first employment. The risk was still elevated more than 20 years after last exposure. Cancer deaths of the nasal cavity/sinus were also increased. This study did not have information on smoking habits, but absence of other smoking-related diseases points to a lack of smoking effect (Rosenman & Stanbury, 1996).
    B) ORAL CANCER
    1) Exposure to hexavalent chromium compounds may be a risk factor for squamous cell cancer of the tongue (Tisch & Maier, 1996).
    C) LYMPHOMA
    1) Two cases of Hodgkin's disease were found in a small population with high environmental exposure to chromium, making an observed risk of 65 to 92 times that for non-exposed populations. This may be a chance occurrence, but is worthy of further investigation (Bick et al, 1996).
    D) CARCINOMA
    1) The solubility of chromium compounds has some influence on carcinogenicity (Lee & Goh, 1988; Levy et al, 1987) Petrille & de Flora, 1987; US Dept of Health Education & Welfare, 1975).

Genotoxicity

    A) Trivalent chromium compounds have generally not been genotoxic unless purified DNA is exposed directly to the test substance. Hexavalent chromium compounds have been mutagenic in bacteria, have caused chromosome aberrations in mammalian cells, and have been associated with increased frequencies of chromosome aberrations in lymphocytes from chromate production workers.

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.

Treatment

Life Support

    A) Support respiratory and cardiovascular function.

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.

Oral Exposure

    6.5.1) PREVENTION OF ABSORPTION/PREHOSPITAL
    A) EMESIS/NOT RECOMMENDED -
    1) DO NOT INDUCE VOMITING - Spontaneous emesis and caustic burns may occur if a toxic dose has been ingested.
    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).
    2) The patient should take nothing by mouth following initial dilution until medical/surgical evaluation is complete.
    C) ACTIVATED CHARCOAL -
    1) Activated charcoal has not been evaluated in chromate poisoning. Activated charcoal may induce vomiting and obscure endoscopy findings; it is not recommended.

Dermal Exposure

    6.9.2) TREATMENT
    A) SUPPORT
    1) Treatment is symptomatic and supportive.

Range Of Toxicity

Summary

    A) The minimum lethal human dose to this agent has not been delineated. Alloy steel plant workers exposed to 0.61 mg Cr (0)/ m(3) for an average of 7 years were found to have normal levels of urinary proteins and enzymes.

Therapeutic Dose

    7.2.1) ADULT
    A) GENERAL/SUMMARY
    1) Although the role of chromium as an essential nutrient in humans is not fully delineated, the estimated requirement for chromium in humans is about 1 microgram/day (Clinical Nutrition Cases, 1988).
    2) Chromium is important in glucose and lipid metabolism, and chromium deficiency may be one factor associated with the development of atherosclerosis (Schroeder et al, 1970).

Maximum Tolerated Exposure

    A) GENERAL/SUMMARY
    1) Alloy steel plant workers exposed to 0.61 mg Cr (0)/ m(3) for an average of 7 years were found to have normal levels of urinary proteins and enzymes (ATSDR, 1993).
    2) Chromium metal does not cause allergic contact dermatitis, chrome ulcers, or nasal septal perforation (Hathaway et al, 1996).
    3) Metallic chromium has low toxicity. A nodular type of pulmonary disease occurred in workers exposed to an airborne concentration of 0.26 mg/m(3) of chromium from ferrochrome alloys, but the effects could not be attributed to chromium exposure alone (Hathaway et al, 1996).
    4) Levels of 12 different chromium aerosols from 1.5 to 40 mcg/m(3) were tested in 250 volunteers. Shock and irritation of the upper respiratory tract resulted from even brief exposure to airborne levels from 10 to 24 mcg/m(3) (HSDB , 2002).
    5) Chromium metal fumes were generated with a plasma flame thrower and inhaled by Sprague-Dawley rats. The concentrations generated ranged between 1.84 mg Cr (0)/ m(3) for 5 H/D, 5 D/W for 1 W to 0.55 mg Cr (0)/ m(3) for 5 H/D, 5 D/W for 2 months. The rats had an increased number of chromosomal aberrations and sister chromatid exchanges in peripheral lymphocytes. Bone marrow cells remained unchanged. The method used to generate the metal fumes may have oxidized the chromium (ATSDR, 1993).
    6) "Studies in rats by intratracheal, intramuscular and intrafemoral administration, in mice and rats by intrapleural and intraperitoneal administration and in mice, rats and rabbits by intravenous injections were inadequate to evaluate the carcinogenicity of chromium metal as a powder" (IARC, 1997).
    7) Chromium metal implanted in the eyes of rabbits did not cause damage (Grant & Schuman, 1993).

Workplace Standards

    A) ACGIH TLV Values for CAS7440-47-3 (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) Adopted Value
    1) Chromium, and inorganic compounds, as Cr, metal and Cr III compounds
    a) TLV:
    1) TLV-TWA: 0.5 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): URT and skin irr
    d) Molecular Weight: Varies
    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) Chromium, and inorganic compounds, as Cr, water-soluble Cr VI compounds
    a) TLV:
    1) TLV-TWA: 0.05 mg/m(3)
    2) TLV-STEL:
    3) TLV-Ceiling:
    b) Notations and Endnotes:
    1) Carcinogenicity Category: A1
    2) Codes: BEI
    3) Definitions:
    a) A1: Confirmed Human Carcinogen: The agent is carcinogenic to humans based on the weight of evidence from epidemiologic studies.
    b) BEI: The BEI notation is listed when a BEI is also recommended for the substance listed. Biological monitoring should be instituted for such substances to evaluate the total exposure from all sources, including dermal, ingestion, or non-occupational.
    c) TLV Basis - Critical Effect(s): URT irr; cancer
    d) Molecular Weight: Varies
    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:
    c) Adopted Value
    1) Chromium, and inorganic compounds, as Cr, insoluble Cr VI compounds
    a) TLV:
    1) TLV-TWA: 0.01 mg/m(3)
    2) TLV-STEL:
    3) TLV-Ceiling:
    b) Notations and Endnotes:
    1) Carcinogenicity Category: A1
    2) Codes: Not Listed
    3) Definitions:
    a) A1: Confirmed Human Carcinogen: The agent is carcinogenic to humans based on the weight of evidence from epidemiologic studies.
    c) TLV Basis - Critical Effect(s): Lung cancer
    d) Molecular Weight: Varies
    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 CAS7440-47-3 (National Institute for Occupational Safety and Health, 2007):
    1) Listed as: Chromium metal
    2) REL:
    a) TWA: 0.5 mg/m(3)
    b) STEL:
    c) Ceiling:
    d) Carcinogen Listing: (Not Listed) Not Listed
    e) Skin Designation: Not Listed
    f) Note(s): See Appendix C
    3) IDLH:
    a) IDLH: 250 mg Cr/m3 (as Cr)
    b) Note(s): Not Listed

    C) Carcinogenicity Ratings for CAS7440-47-3 :
    1) ACGIH (American Conference of Governmental Industrial Hygienists, 2010): A4 ; Listed as: Chromium, and inorganic compounds, as Cr, metal and Cr III compounds
    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.
    2) ACGIH (American Conference of Governmental Industrial Hygienists, 2010): A1 ; Listed as: Chromium, and inorganic compounds, as Cr, water-soluble Cr VI compounds
    a) A1 :Confirmed Human Carcinogen: The agent is carcinogenic to humans based on the weight of evidence from epidemiologic studies.
    3) ACGIH (American Conference of Governmental Industrial Hygienists, 2010): A1 ; Listed as: Chromium, and inorganic compounds, as Cr, insoluble Cr VI compounds
    a) A1 :Confirmed Human Carcinogen: The agent is carcinogenic to humans based on the weight of evidence from epidemiologic studies.
    4) EPA (U.S. Environmental Protection Agency, 2011): Not Listed
    5) 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): 3 ; Listed as: Chromium, metallic
    a) 3 : The agent (mixture or exposure circumstance) is not classifiable as to its carcinogenicity to humans. This category is used most commonly for agents, mixtures and exposure circumstances for which the evidence of carcinogenicity is inadequate in humans and inadequate or limited in experimental animals. Exceptionally, agents (mixtures) for which the evidence of carcinogenicity is inadequate in humans but sufficient in experimental animals may be placed in this category when there is strong evidence that the mechanism of carcinogenicity in experimental animals does not operate in humans. Agents, mixtures and exposure circumstances that do not fall into any other group are also placed in this category.
    6) 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): 1 ; Listed as: Chromium VI compounds
    a) 1 : The agent (mixture) is carcinogenic to humans. The exposure circumstance entails exposures that are carcinogenic to humans. This category is used when there is sufficient evidence of carcinogenicity in humans. Exceptionally, an agent (mixture) may be placed in this category when evidence of carcinogenicity in humans is less than sufficient but there is sufficient evidence of carcinogenicity in experimental animals and strong evidence in exposed humans that the agent (mixture) acts through a relevant mechanism of carcinogenicity.
    7) NIOSH (National Institute for Occupational Safety and Health, 2007): Not Listed ; Listed as: Chromium metal
    8) MAK (DFG, 2002): Category 2 ; Listed as: Chromium(VI) compounds (as dusts/aerosols), with the exception of those practically insoluble in water such as lead chromate, barium chromate (but zinc chromate Section III Category 1)
    a) Category 2 : Substances that are considered to be carcinogenic for man because sufficient data from long-term animal studies or limited evidence from animal studies substantiated by evidence from epidemiological studies indicate that they can make a significant contribution to cancer risk. Limited data from animal studies can be supported by evidence that the substance causes cancer by a mode of action that is relevant to man and by results of in vitro tests and short-term animal studies.
    9) NTP (U.S. Department of Health and Human Services, Public Health Service, National Toxicology Project ): K ; Listed as: Chromium Hexavalent Compounds
    a) K : KNOWN = Known to be a human carcinogen

    D) OSHA PEL Values for CAS7440-47-3 (U.S. Occupational Safety, and Health Administration (OSHA), 2010):
    1) Listed as: Chromium (II) compounds (as Cr)
    2) Table Z-1 for Chromium (II) compounds (as Cr):
    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: 0.5
    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
    3) Listed as: Chromium (III) compounds (as Cr)
    4) Table Z-1 for Chromium (III) compounds (as Cr):
    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: 0.5
    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
    5) Listed as: Chromium metal and insol salts (as Cr)
    6) Table Z-1 for Chromium metal and insol salts (as Cr):
    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: 1
    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) References: (ACGIH, 1996; Lewis, 2000 RTECS, 2002)
    7.7.2) RISK ASSESSMENT VALUES
    A) References: (ACGIH, 1996; Lewis, 2000 RTECS, 2002)
    1) NOAEL- (INHALATION)RABBIT:
    a) 0.6 or 3.1 mg Cr (0)/m(3) for 6H/D, 5D/W, for 4W (ACGIH, 1996)

Physicochemical

Physical Characteristics

    A) Brittle, hard, odorless solid with lustrous, blue-white or steel-gray appearance (NIOSH , 2001).
    B) Chromium is an odorless, steel-gray, semi-gray, or blue-white, lustrous, brittle metal with a body-centered cubic structure. It is as hard as corundum and less fusible than platinum (Budavari, 1996; Ashford, 1994; Lewis, 1997; HSDB , 2001).
    C) Note: The physical/chemical information listed is for elemental chromium only. For additional information on chromium compounds, please refer to individual HAZARDTEXT documents.

Ph

    A) Elemental chromium is amphoteric (HSDB , 2001).
    B) Bivalent chromium compounds are basic, the trivalent compounds are amphoteric, and the hexavalent compounds are acidic (Clayton & Clayton, 1994).

Molecular Weight

    A) 52.00

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