

General Populations

 The general population may be exposed 

to chromium daily through food, 

drinking water, and air.

 The predominant route of exposure for 

the general population is ingestion of 

chromium in the diet. 

 Exposure may also occur through 

inhalation of contaminated air and 

consumption of contaminated water. 

 Chromium(III) is an essential nutrient 

required for normal energy metabolism.

 The Institute of Medicine of the National 

Academy of Sciences determined an 

adequate intake of chromium(III) of 20–

45 μg/day for adolescents and adults.

Occupational Populations

 Workers in approximately 80 industries 

may be exposed to chromium(VI). 

 Occupational exposure to chromium 

primarily occurs from chromate 

production, stainless steel production and 

welding, chromium plating, ferrochrome 

alloys, and chrome pigment production. 

Workers in the tanning industries are also 

potentially exposed to chromium.

Toxicokinetics

 The toxicokinetics of a given chromium 

compound depend on the valence state 

of the chromium atom and its solubility. 

 Chromium is absorbed through the 

lungs; less-water soluble compounds have 

a longer retention time in the lung than 

more soluble forms.

 Less than 10% of an ingested chromium 

dose is absorbed from the gastrointestinal 

tract. More soluble compounds have 

higher absorption fractions. 

 Chromium can penetrate human skin to 

some extent, especially if the skin is 

damaged.

 Absorbed chromium is distributed to 

nearly all tissues, with the highest 

concentrations found in kidneys and 

liver. Bone is also a major depot and may 

contribute to long-term retention. 

 Chromium(VI) is reduced to 

chromium(III) via the intermediate forms 

of chromium(V) and chromium(IV). 

 Absorbed chromium is predominantly 

excreted in the urine. 

Normal Human Levels

 In the general population, the mean 

levels of chromium in serum and urine 

are 0.10–0.16 and 0.22 μg/L, respectively.

Biomarkers

 Chromium(III) is an essential element 

and is normally present in blood and 

urine. 

 Exposure to higher than normal levels of 

chromium may result in increased 

chromium levels in blood, urine, expired 

air, hair, and nails. 

 Elevations in chromium in blood and 

urine are considered the most reliable 

biomarkers of exposure.

Environmental Levels

Air

 Median concentrations in ambient air are 

<20 ng/m3. 

 Indoor air in areas with cigarette smoking 

can be 10–400 times higher than outdoor 

air. 

Sediment and Soil

 The mean concentration of chromium in 

soil is 37.0 mg/kg. 

Water

 Most drinking water supplies in the 

United States contain <5 μg/L of 

chromium. 

Reference

Agency for Toxic Substances and Disease

Registry (ATSDR). 2012. Toxicological

Profile for Chromium. Atlanta, GA: U.S. 

Department of Health and Human

Services, Public Health Services.

ToxGuideTM

for

Chromium

Cr

CAS# 7440-47-3

October 2012

U.S. Department of Health and

Human Services

Public Health Service

Agency for Toxic Substances

and Disease Registry

www.atsdr.cdc.gov

Contact Information:

Division of Toxicology

and Human Health Sciences

Environmental Toxicology Branch

1600 Clifton Road NE, F-57

Atlanta, GA 30333

1-800-CDC-INFO

1-800-232-4636

http://www.atsdr.cdc.gov/toxprofiles/index.asp

Toxicokinetics and

Normal Human Levels

Biomarkers/Environmental

Levels Sources of Exposure

The ToxGuideTM is developed to be used as a pocket guide. Tear off at perforation and fold along lines.
Routes of Exposure Relevance to Public Health (Health Effects) Chemical and Physical 

Information

Chromium is a Metal

 Chromium is a naturally occurring 

element found in rocks, animals, plants,

and soil, where it exists in combination 

with other elements to form various 

compounds.

 The main forms of chromium are: 

chromium(0), chromium(III), and 

chromium(VI).

 Chromium is widely used in 

manufacturing processes to make various 

metal alloys such as stainless steel.

 Chromium can be found in many 

consumer products such as: wood 

treated with copper dichromate, leather 

tanned with chromic sulfate, stainless 

steel cookware, and metal-on-metal hip 

replacements.

 Inhalation – Predominant route of 

exposure for occupational populations.

 Oral – Predominant route of exposure 

for the general population.

 Dermal – Minor route of exposure for 

the general population.

Chromium in the 

Environment

 Chromium is released into the 

atmosphere via industrial, commercial, 

and residential fuel combustion of natural 

gas, oil, and coal and from emissions 

from metal industries such as chrome 

plating and steel production. 

 Approximately 1/3 of atmospheric 

releases are believed to be in the form of 

chromium(VI). 

 Electroplating, leather tanning, and textile 

industries release large amounts of 

chromium to surface water.

 Chromium is primarily removed from the 

atmosphere by fallout and precipitation, 

the residence time is expected to be 

<10 days. 

 Most of the chromium released in water 

will be deposited in the sediments. 

 Chromium is not believed to biomagnify 

in the food chain.

Minimal Risk Levels (MRLs)

Inhalation

 No acute-duration inhalation MRLs 

(≤14 days) were derived for Cr(III) or 

Cr(VI).

 Intermediate-duration inhalation MRLs 

(15–364 days) were derived: 

5x10-6 mg Cr/m3 for Cr(VI) aerosols and 

mists

3x10-4 mg Cr/m3 for Cr(VI) particulates

5x10-3 mg Cr/m3 for insoluble Cr(III) 

particulates 

1x10-4 mg Cr/m3 for soluble Cr(III) 

particulates

 An MRL of 5x10-6 mg Cr/m3 has been 

derived for chronic-duration inhalation 

exposure to Cr(VI) aerosols and mists of 

(≥1 year).

Oral

 No acute-duration oral MRL(≤14 days)

was derived for Cr(VI).

 An MRL of 5x10-3 mg Cr/kg/day has 

been derived for intermediate-duration 

oral exposure to Cr(VI) (15–364 days).

 An MRL of 9x10-4 mg Cr/kg/day has 

been derived for chronic-duration oral 

exposure to Cr(VI) (≥1 year).

 No acute-, intermediate-, or chronic 

duration oral MRLs were derived for 

Cr(III).

Health effects are determined 

by the dose (how much), the

duration (how long), and the

route of exposure.

Health Effects

 In general, chromium(VI) compounds 

are more toxic than chromium(III) 

compounds.

 The most sensitive targets of 

chromium(VI) are the respiratory (nasal 

and lung irritation and altered pulmonary 

function following inhalation exposure), 

gastrointestinal (irritation, ulceration, and 

stomach and small intestine lesions 

following oral exposure), hematological 

(microcytic, hypochromic anemia), and 

reproductive (decreased sperm count and 

epididymal damage) systems. 

 The primary targets of chromium(III) 

compounds are the respiratory (following 

inhalation exposure) and immunological 

systems. Chromium allergic dermatitis is 

typically elicited by dermal contact in 

sensitized individuals. 

 DHHS, IARC, and EPA have classified 

chromium(VI) as a human carcinogen. 

 IARC has classified chromium(III) and 

metallic chromium as not classifiable as 

to their carcinogenicity to humans.

Children’s Health

 It is unknown whether children are more 

sensitive to chromium poisoning than 

adults.

 In laboratory animals, chromium(VI)

causes miscarriages, low birth weight, and 

changes in development of skeleton and 

reproductive system. These 

developmental effects may be related, in 

part, to maternal chromium toxicity.