Industrial Hygiene

Hexavalent Chromium

Last Updated: August 23, 2019

Hexavalent Chromium (Cr(VI)) is a form of the element Chromium. Chromium is a shiny metal, but materials containing Cr(VI) may take on a variety of colors and forms, such as liquids, dusts, mists, or fumes.

The purpose of this webpage is to provide information regarding Cr(VI).  This webpage will cover recent changes to the American Conference of Governmental Industrial Hygienists Threshold Limit Value (ACGIH TLV®)and the U.S. Army Medical Command (MEDCOM) implementation plan for the new Cr(VI)TLV® for the potentially affected workforce and those who are responsible for protecting worker health and safety.

  • U.S. Army policy mandates the use of ACGIH TLV® as the Occupational Exposure Limit (OEL) criteria when the Occupational Safety and Health Administration (OSHA) Permissible Exposure Limits (PELs) are less protective or when no OSHA PEL exists. As a result of this policy, the 2018 ACGIH TLVs® are applied as the Army OELs for Chromium Metal (Cr(0)), Trivalent Chromium (Cr(III)), and Cr(VI).
    • The 2018 ACGIH TLVs® for Cr(0), Cr(III), and Cr(VI) are significantly lower than previously published values.
    • The ACGIH TLVs® for Cr(0), Cr(III), and Cr(VI) are 0.5 milligrams per cubic meter of air (mg/m3), 0.003 mg/m3, and 0.0002 mg/m3, respectively.  All chromium TLVs® exposures are measured as inhalable fraction of the aerosol.- The ACGIH TLV®s for Cr(0), Cr(III), and Cr(VI) are 0.5 milligrams per cubic meter of air (mg/m3), 0.003 mg/m3, and 0.0002 mg/m3, respectively.  All chromium TLVs® exposures are measured as inhalable fraction of the aerosol.
    • Technical, economic, and resource challenges prevent immediate implementation of the 2018 ACGIH Cr(0), Cr(III), and Cr(VI) TLVs® .    
  • MEDCOM has developed an Army-wide implementation plan for the new TLVs® and is partnering with Army leaders as well as experts from the U.S. Army Combat Readiness Center and the U.S. Army Public Health Center to ensure implementation is accomplished in a timely and comprehensive manner.
  • Cr(VI) is a known human carcinogen and can present a number of other health hazards without proper controls and personal protective equipment (PPE). Access to accurate, relevant, and consistent information about the Army's efforts to reduce worker exposure is critical to protecting worker health and safety.


QUICK LINK : Click here for additional resources for workers, healthcare providers, and industrial hygienists

 

What is Cr(VI)?

Cr(VI) is one of the valence states (+6) of the element chromium. Materials containing Cr(VI) may take on a variety of colors and forms, such as liquids, dusts, mists, or fumes.  It is usually produced by an industrial process.

How is Cr(VI) used?

Cr(VI) Is typically produced by an industrial process and is valued for its hardness and corrosion resistance.

Common Army processes associated with occupational Cr(VI) exposure are:

  • aircraft maintenance
  • brazing/soldering/ welding/cutting
  • coating and painting operations
  • metal treatment and metal machining

How are people exposed to Cr(VI)?

Occupational exposure can occur from inhalation of dusts, mists, or fumes containing Cr(VI), from eye or skin contact, and can also occur via ingestion.

How to reduce exposure to Cr(VI)?

The best way to protect workers from Cr(VI) exposure is to switch to Cr(VI)-free products. In cases where this is not possible implement these controls:

◾Engineering: use ventilation to reduce Cr(VI) in the air (e.g., shrouded tools, high-efficiency particulate air (filtered) vacuums, downdraft tables)

◾Administrative: improve work practices to reduce Cr(VI) exposure (e.g., training, standard operating procedures, housekeeping program).

◾PPE:  protective clothing worn to reduce Cr(VI) exposure (e.g., respirators, coveralls, nitrile gloves)


What are the known health effects of inhaling Cr(IV)?

Hexavalent chromium compounds have been shown to cause lung cancer in humans when inhaled.

The Report on CarcinogensExternal Link lists hexavalent chromium compounds as known human carcinogens. Studies have consistently shown increased lung cancer rates in workers who were exposed to high levels of chromium in workroom air.

Some of the health effects from Cr(VI) exposures include nasal and sinus cancers, kidney and liver damage, nasal and skin irritation and ulceration, and eye irritation and damage.

Skin exposure can result in chrome ulcers, which are usually painless but can lead to secondary infection. Skin exposure can also result in irritation or allergic dermatitis. An allergy can be confirmed by patch testing.

OSHA has established medical surveillance standards for workers exposed to Cr(VI) which are found in 29 CFR 1910.1026(k), 29 CFR 1910, Toxic and Hazardous Substances. The exam must be performed under the supervision of a physician or other licensed healthcare professional (PLHCP) and at no cost to the employee. The purpose of the exam is to determine if the worker can be exposed to Cr(VI) without adverse health effects; to detect adverse health effects of Cr(VI) so that appropriate interventions can be taken; and to determine the workers’ fitness to wear a respirator.

Per OSHA, workers who are exposed to Cr(VI) at or above the Action Level of 0.0025 mg/m3 for 30 days or more per year must be enrolled in medical surveillance. However, by policy, the Army follows the ACGIH TLV® if more stringent. In March 2018, the ACGIH published an updated TLV® of 0.0002 mg/m3. Additionally, workers who experience signs and symptoms of Cr(VI) exposure or who were exposed in an unintentional release of Cr(VI) must be enrolled in medical surveillance. Medical surveillance must occur within 30 days of job assignment with Cr(VI) exposure, annually, after any suspected emergency exposure and at termination of employment or acute exposure.

When the Army implements sampling in accordance with the 2018 ACGIH TLV® for Cr(0), Cr(III), and Cr(VI), Industrial Hygienists will recommend that personnel who are, or may be, occupationally exposed to Cr(0), Cr(III), and Cr(VI) at or above the OSHA AL or 2018 ACGIH TLVs® for 30 or more days per year be enrolled in a medical surveillance program.

The exam must include a medical history focusing on workers’ past, present and future exposure to Cr(VI); history of smoking; history of respiratory system dysfunction including asthma; examination of the respiratory system; and examination of the skin for dermatitis or ulceration. Workers who smoke should be counseled to quit tobacco because it has synergistic effects with Cr(VI). The PLHCP may also order additional tests that they feel are necessary such as spirometry. Any spirometry should be performed in accordance with American Thoracic Society standards.  The PLHCP is responsible for providing a written statement within 30 days on any detected medical condition that places the worker at increased risk of impairment due to Cr(VI), provide recommendations for the use of personal protection equipment such as respirators and a statement that the PLHCP has explained the results of the exam to the worker.

Reference: Hexavalent Chromium Medical Surveillance Exams for Army Personnel, APHC Fact Sheet

Scroll down for resources for specific audiences.

Resources for Workers:

  1. Chromium VI in the Workplace; U.S. Army Combat Readiness Center
  2. Hexavalent Chromium; National Institute of Environmental Sciences External Link
  3. Hexavalent Chromium; OSHA External Link
  4. Health Effects of Hexavalent Chromium; OSHA External Link


Resources for Industrial Hygienists:

  1. OSHA Interpretation on Hexavalent Chromium Sampling ** PLEASE NOTE:  As of May 2019, OTSG received an interpretation from OSHA allowing IOM (inhalable) results to be compared to the OSHA PEL. Total sampling is no longer required.**
  2. ACGIH 2018 TLV®s and BEIs; ACGIH External Link
  3. Criteria for a Recommended Standard - Occupational Exposure to Hexavalent Chromium; Centers for Disease Control and Prevention (CDC) 
  4. U.S. Army Combat Readiness Center: Toxic and Hazardous Substances - Resources & Control Plans
  5. Chromium VI Compounds (Hexavalent Chromium); OSHA Occupational Chemical Database External Link
  6. Hazard Communication Standard; OSHA External Link
  7. Hexavalent Chromium Exposure Control Package; Washington State Department of Labor and Industries’ Safety & Health Project External Link
  8. OSHA Standard 1910.1026, Chromium (IV); OSHAExternal Link
  9.  GilAir Plus IOM Procedures
  10. Hexavalent Chromium Sampling Strategy for IOM, Updated June 2019

Resources for Healthcare Providers:

Statutory Documents:
  1. 29 CFR 1910.1026(k), Chromium (VI), Medical surveillance External Link
  2. 29 CFR 1910.1020, Access to employee exposure and medical records External Link
  3. 29 U.S.C. § 654, Section 5 Duties External Link
Army Regulations and Implementing Guidance:
  1. AR 11-34, The Army Respiratory Protection ProgramExternal Link
  2. DA PAM 40-11, Preventive Medicine External Link
Clinical Practice Resources, SOPs, and Guidance:
  1. NIOSH Occupational Health Guideline for Chromic Acid and ChromatesExternal Link
  2. NMCPHC Technical Manual™ OM 6260, “Medical Surveillance Procedures Manual and Medical Matrix,” (Navy Medical Matrix) External Link
  3. DoD 6055.05-M, Occupational Medical Examinations and Surveillance, 02 May, 2007 (Change 2, 17 April 2017), Table C2. T7 External Link
  4. TB MED 509, Spirometry in Occupational Health ProgramsExternal Link
  5. Army Occupational Medicine Resource Center, maneuver to "Contents" then "OHOS" External Link
  6. The PHC Model SOP Chromium Medical SurveillanceExternal Link