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Chromium (VI) (Hexavalent Chromium)

General Description

Synonyms:

Chromium VI; Hexavalent chromium; Cr(VI)

OSHA IMIS Code Number:

0689

Chemical Abstracts Service (CAS) Registry Number:

18540-29-9 (hexavalent chromium); 1333-82-0 [chromium (VI) oxide]

NIOSH Registry of Toxic Effects of Chemical Substances (RTECS) Identification Number:

GB6650000 [chromium (VI) oxide (1:3)]

Department of Transportation Regulation Number (49 CFR 172.101) and 2012 Emergency Response Guidebook [4 MB PDF, 392 pages]:

1463 141 (chromium trioxide, anhydrous)

U.S. Environmental Protection Agency (EPA) Hazard Summary - Chromium Compounds:

Uses, sources and potential exposure, acute and chronic health hazard information, and more

Exposure Limits and Health Effects

Exposure Limit Limit Values HE Code Health Factors and Target Organs

OSHA Permissible Exposure Limit (PEL) - General Industry*

See 29 CFR 1910.1026 Chromium (VI)

Note: OSHA's standard applies to occupational exposures to any chromium species with a valence of positive six, regardless of form or compound.

  • 5.0 µg/m3 TWA
  • 2.5 µg/m3 TWA Action Level
HE1 Cancer (lung, nasopharynx, oropharynx, nasal passages)
HE14 Eye irritation and skin sensitization

OSHA PEL - Construction Industry*

See 29 CFR 1926.1126 Chromium (VI)

  • 5.0 µg/m3 TWA
  • 2.5 µg/m3 TWA Action Level
HE1 Cancer (lung, nasopharynx, oropharynx, nasal passages)
HE14 Eye irritation and skin sensitization

OSHA PEL - Shipyard Employment*

See 29 CFR 1915.1026 Chromium (VI)

  • 5.0 µg/m3 TWA
  • 2.5 µg/m3 TWA Action Level
HE1 Cancer (lung, nasopharynx, oropharynx, nasal passages)
HE14 Eye irritation and skin sensitization

National Institute for Occupational Safety and Health (NIOSH) Recommended Exposure Limit (REL)

See Appendix A and Appendix C

Note: The REL applies to all Cr(VI) compounds.

  • 0.0002 mg/m3 (8 hr TWA)
HE1 Lung cancer
HE3 Liver damage, with jaundice; blood changes, including leukocytosis, leukopenia, and eosinophilia; erosion and discoloration of teeth
HE4 Eye injury; kidney and stomach damage, causing vomiting and epigastric pain; severe irritation of the nose, throat, bronchial tubes, and lungs
HE9 Asthmatic bronchitis
HE11 Lung damage, including pulmonary congestion and edema
HE14 Dermatitis, skin ulceration, nasal mucosa irritation and ulceration, nasal septum perforation, eardrum perforation, conjunctivitis

American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Value (TLV) (2004)

Water-Soluble Cr(VI) compounds, as Cr

  • 0.05 mg/m3 TWA

  • A1; BEI
HE1 Lung cancer
HE14 Respiratory irritation, dermatitis

American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Value (TLV) (2004)

Insoluble Cr(VI) compounds, as Cr

  • 0.01 mg/m3
  • TWA
  • A1
HE1 Lung cancer
HE14 Respiratory irritation, dermatitis

CAL/OSHA PELs

See also Sections 1532.2, 5206, and 8359

  • 0.005 mg/m3 TWA
  • 0.1 mg/m3 Ceiling

*The chromic acid and chromates PEL of 0.1 mg/m3 TWA (see 29 CFR 1910.1000 Table Z-2) applies to any operations or sectors for which the PEL in the chromium (VI) standard (Sections 1910.1026, 1926.1126, or 1915.1026) is stayed or is otherwise not in effect.

National Toxicology Program (NTP) carcinogenic classification:

Known to be a human carcinogen [186 KB PDF, 4 pages]

International Agency for Research on Cancer (IARC) carcinogenic classification:

Group 1 [549 KB PDF, 147 pages] (carcinogenic to humans)

EPA carcinogenic classification:

Known/likely human carcinogen

EPA Inhalation Reference Concentration (RfC):

1x10-4 mg/m3 (particulates); 8x10-6 mg/m3 (aerosol mists)

Agency for Toxic Substances and Disease Registry (ATSDR) Inhalation Minimal Risk Level (MRL):

Aerosol mists: 0.000005 mg/m3 (intermediate); 0.000005 mg/m3 (chronic)
Particulates: 0.0003 mg/m3 (intermediate)

NIOSH Immediately Dangerous to Life or Health (IDLH) concentration:

Not established

Notes on Other Potential Health Effects and Hazards

  1. Recent studies indicate occupational exposure to hexavalent chromium may have genotoxic effects (ATSDR 2008; Zhang et al. 2011; Balachandar et al. 2010).

Date Last Revised:

09/06/2012

Literature Basis

  • ACGIH: Documentation of the Threshold Limit Values (TLVs) and Biological Exposure Indices (BEIs) - Chromium and Inorganic Compounds. 2004.
  • ATSDR: Toxicological profile for chromium. September 20012.
  • Balachandar V, Arun M, Mohana Devi S, Velmurugan P, Manikantan P, Karthick Kumar A, Sasikala K, Venkatesan C.: Evaluation of the genetic alterations in direct and indirect exposures of hexavalent chromium [Cr(VI)] in leather tanning industry workers North Arcot District, South India. Int Arch Occup Environ Health. 83(7):791-801, 2010.
  • NIOSH: Criteria for a Recommended Standard: Occupational Exposure to Chromium (VI).
  • NIOSH: Draft Criteria Document Update - Occupational Exposure to Hexavalent Chromium. September 2008.
  • NIOSH/IPCS: International Chemical Safety Cards - Chromium (VI) Oxide.
  • OSHA: Occupational Safety and Health Standards - Chromium VI. October 27, 2004.
  • Zhang XH, Zhang X, Wang XC, Jin LF, Yang ZP, Jiang CX, Chen Q, Ren XB, Cao JZ, Wang Q, Zhu YM: Chronic occupational exposure to hexavalent chromium causes DNA damage in electroplating workers. BMC Public Health. 11:224. 2011.

Monitoring Methods used by OSHA

Three OSHA sampling and analytical methods for Cr (VI) are cited below:

Primary Laboratory Sampling/Analytical Method (SLC1):
  • low ash 37-mm or 25-mm PVC filter in polystyrene cassette
  • Do not use the preweighed custom-made cassettes with the aluminum cone that are intended for gravimetric sampling.
  • Chromium plating samples can be collected on either PVC filters or on quartz fiber filters coated with sodium hydroxide. The coated quartz fiber filters are preferred for sample stability.
  • CAUTION: Do not use the coated quartz fiber filters for any operation other than chromium plating.
  • analytical solvent: carbonate/bicarbonate buffer
  • maximum volume: 960 Liters
  • maximum flow rate: 2 L/min (TWA)
  • minimum volume: 200 Liters
  • maximum flow rate: 2 L/min
  • current analytical method: Ion Chromatography; IC/UV
  • method reference: OSHA Analytical Method (OSHA ID-215 (version 2)
  • method classification: Fully Validated

note: Chromium plating samples collected on PVC filters must be shipped to the Salt Lake Technical Center within 24 hours of sampling by overnight delivery. These samples must be stabilized by laboratory personnel as described in Section 2 of OSHA ID-215 (version 2).

note: Welding samples must be shipped to the Salt Lake Technical Center within 24 hours of sampling by overnight delivery.

note: OSHA CSHOs should obtain low-background PVC filters and quartz fiber filters coated with sodium hydroxide from the Salt Lake Technical Center to sample hexavalent chromium.

Wipe Sampling Method:
  • 37-mm PVC filter or 37-mm binderless quartz fiber filters
  • method reference: OSHA Analytical Method (OSHA W4001)
  • method classification: Fully Validated

note: Wipe samples taken in chromium plating and welding operations should be shipped to the Salt Lake Technical Center within 24 hours after sampling by overnight delivery. Chromium plating samples collected on PVC filters must be stabilized by laboratory personnel as described in Section 2 of W4001.

Bulk Sampling Method:
  • solids require approximately 10 grams, liquids 10 mL; place in 20-mL glass vials with PTFE-lined caps
  • method reference: OSHA Analytical Method (OSHA ID-215, June 1998)

note: Collect samples wearing protective gloves, such as nitrile or PVC. Ship bulk samples to analytical laboratory separately from wipe or air samples. Ship by overnight delivery if that delivery service was used for the associated air samples.

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