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PUBLIC HEALTH STATEMENT 

Tungsten 

CAS#: 7440-33-7 

Division of Toxicology August 2005 

This Public Health Statement is the summary 

chapter from the Toxicological Profile for 

Tungsten. It is one in a series of Public Health 

Statements about hazardous substances and their 

health effects. A shorter version, the ToxFAQsTM, 

is also available. This information is important 

because this substance may harm you. The effects 

of exposure to any hazardous substance depend on 

the dose, the duration, how you are exposed, 

personal traits and habits, and whether other 

chemicals are present. For more information, call 

the ATSDR Information Center at 1-888-422-8737. 

This public health statement tells you about 

tungsten and the effects of exposure to it. 

The Environmental Protection Agency (EPA) 

identifies the most serious hazardous waste sites in 

the nation. These sites are then placed on the 

National Priorities List (NPL) and are targeted for 

long-term federal clean-up activities. Tungsten has 

been found in at least 6 of the 1,662 current or 

former NPL sites. Although the total number of 

NPL sites evaluated for this substance is not known, 

the possibility exists that the number of sites at 

which tungsten is found may increase in the future 

as more sites are evaluated. This information is 

important because these sites may be sources of 

exposure and exposure to this substance may harm 

you. 

When a substance is released either from a large 

area, such as an industrial plant, or from a container, 

such as a drum or bottle, it enters the environment. 

Such a release does not always lead to exposure. 

You can be exposed to a substance only when you 

come in contact with it. You may be exposed by 

breathing, eating, or drinking the substance, or by 

skin contact. 

If you are exposed to tungsten, many factors will 

determine whether you will be harmed. These 

factors include the dose (how much), the duration 

(how long), and how you come in contact with it. 

You must also consider any other chemicals you are 

exposed to and your age, sex, diet, family traits, 

lifestyle, and state of health. 

1.1 WHAT IS TUNGSTEN? 

Tungsten is a naturally occurring element that, in 

most environments, is a solid. In nature, it occurs in 

rocks and soil as minerals, but never as the pure 

metal. Two kinds of tungsten-bearing mineral 

rocks, called wolframite and scheelite, are mined 

commercially. The mineral ore is processed to 

recover the tungsten and turn it into either chemical 

compounds or metal. Elemental tungsten, like 

elemental copper or gold, is a metal. Its color can 

range from tin white (for the pure metal) to steel 

gray (for metal that has impurities in it). Tungsten 

can be used as a pure metal or mixed with other 

metals to make alloys. Tungsten alloys tend to be 

strong and flexible, resist wear, and conduct 

electricity well. Tungsten and its alloys are used as 

light bulb filaments, as the part of x-ray tubes where 

x-rays are formed, as a catalyst to speed up 

chemical reactions, as a component of steel in highspeed tools, in turbine blades, in phonographic 

needles, as welding electrodes, as gyroscope 

wheels, as counterbalance and fishing weights, in 

darts, and in golf club components. They can be 

used in bullets (as a replacement for lead) and in 

armor penetrators (as a substitute for depleted 

DEPARTMENT of HEALTH AND HUMAN SERVICES, Public Health Service
 

Agency for Toxic Substances and Disease Registry 

www.atsdr.cdc.gov/ Telephone: 1-888-422-8737 Fax: 770-488-4178 E-Mail: atsdric@cdc.gov 
 

 

 

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PUBLIC HEALTH STATEMENT 

Tungsten 

CAS#: 7440-33-7 

Division of Toxicology August 2005 

uranium). Chemical compounds of tungsten are 

used for many purposes. Cemented tungsten 

carbide, a hard substance used to make grinding 

wheels and cutting or forming tools, is the most 

common tungsten compound. Other tungsten 

compounds are used in ceramic pigments, as fire 

retardant coatings for fabrics, and as fade-resistant 

dyes for fabrics. 

1.2 WHAT HAPPENS TO TUNGSTEN 

WHEN IT ENTERS THE 

ENVIRONMENT? 

Tungsten occurs naturally in the environment, in 

minerals, but not as the pure metal. As an element, 

tungsten can be neither created nor destroyed 

chemically, although tungsten can change forms in 

the environment. 

Tungsten is released into air as fine dust-like 

particles by weathering. Emissions from hard metal 

industries also increase tungsten levels in air. The 

amount of tungsten that has been measured in the 

ambient air is, in general, less than 10 billionths of a 

gram per cubic meter (or parts per billion [ppb]). 

Very small dust particles of tungsten in the air fall 

out onto surface water, plant surfaces, and soil 

either by themselves or when rain or snow falls. 

These tungsten particles eventually recycle back in 

the soil or in the bottoms of lakes, rivers, and ponds, 

where they stay and mix with tungsten that is 

already there. 

Tungsten in water originates mainly from 

dissolution of tungsten from rocks and soil that 

water runs over and through. Tungsten has not been 

detected in the vast majority of surface water and 

groundwaters of the United States. Some 

exceptions include areas near mines and natural 

deposits, and also in Churchill County (City of 

Fallon), in Nevada, where tungsten has been 

detected in municipal water and groundwater. Only 

a very small fraction of tungsten in water originates 

from the settling of dust out of the air. Most 

tungsten products of human-origin that enter 

waterways originate from industry discharges of 

waste water. Tungsten in water may be in either 

soluble or insoluble forms. Insoluble tungsten in 

water can settle to the bottom where it enters 

sediment. Some insoluble tungsten compounds, 

however, can remain suspended in ocean water for 

many years, requiring as long as 1,000 years to 

settle to the bottom. 

Tungsten occurs naturally in soil as a mineral, or 

component of soil. It occurs in amounts that vary 

over a wide range from less than 1 to as high as 

83 thousandths of a gram per kilogram of soil. 

Another way to say this is that the tungsten 

concentration ranges from 1 to 83 parts per million 

(ppm) in soil by weight. Disposal of coal ash, 

incinerator ash, and industrial wastes may increase 

the amount of tungsten in soil. A portion of 

tungsten in soil does not dissolve in water, but 

remains bound and is not likely to move deeper into 

the ground and enter groundwater. The remaining 

soluble portion may move deeper into the ground 

and enter groundwater if the pH is greater than 7. 

In the environment, chemical reactions can change 

the water-soluble tungsten compounds into 

insoluble forms. In some cases, water-insoluble 

tungsten compounds can change to soluble forms. 

In general, exposure to water-soluble tungsten 

compounds in the environment will pose a greater 

threat to human health than water-insoluble forms. 

DEPARTMENT of HEALTH AND HUMAN SERVICES, Public Health Service
 

Agency for Toxic Substances and Disease Registry 

www.atsdr.cdc.gov/ Telephone: 1-888-422-8737 Fax: 770-488-4178 E-Mail: atsdric@cdc.gov 
 

 

 

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PUBLIC HEALTH STATEMENT 

Tungsten 

CAS#: 7440-33-7 

Division of Toxicology August 2005 

1.3 HOW MIGHT I BE EXPOSED TO 

TUNGSTEN? 

You can be exposed to low levels of tungsten by 

breathing air, drinking water, or eating food that 

contains tungsten. The average ambient 

concentration of tungsten in air has been reported to 

be less than 10 nanograms in a cubic meter of air 

(1 nanogram is 1 billionth of a gram). Cities have 

higher levels of tungsten in the air because tungsten 

is released from industry. Tungsten has been 

detected in municipal water from Fallon, Nevada. 

However, the amounts of tungsten in drinking water 

are generally not known. This is probably because 

the tungsten levels are lower than the laboratory 

methods are able to detect without concentrating 

samples, or the laboratory does not measure for 

tungsten. The amounts in foods are generally not 

known, possibly for the same reasons. Tungsten in 

plants was either taken up by the plant or was 

attached to the plant as a component of the soil. 

The concentration of tungsten in onions collected 

from Denmark is 17 micrograms in a kilogram of 

fresh vegetables. Although very limited data are 

available, exposure to tungsten from air, drinking 

water, and food is expected to be insignificant. 

In certain workplaces, you can be exposed to levels 

of tungsten in air that are higher than background 

levels, which are very small or none. Exposures are 

mostly in the form of tungsten metal or tungsten 

carbide. Occupational exposure to tungsten occurs 

primarily at places where individuals use hard 

metals containing tungsten or are engaged in the 

machining of these metals. This includes the 

grinding (pointing) of tungsten metal welding 

electrodes prior to use. Occupational exposure to 

tungsten carbide occurs during the machining of 

tungsten carbide tools in the manufacturing process. 

The total number of individuals occupationally 

exposed to tungsten or its compounds has been 

estimated to be about 47,000. 

Tungsten metal and metal alloys occur in consumer 

products such as electronics, light bulb filaments, 

cemented tungsten carbide grinding wheels, carbide 

tipped tools, and “green” bullets. No other 

consumer products or products used in crafts, 

hobbies, or cottage industries were identified that 

contain significant amounts of tungsten. It is 

unlikely that tungsten present in consumer products 

poses a hazard. However, appropriate dust masks 

are recommended for amateur craftsmen engaging 

in activities that may potentially produce tungsten 

carbide dust (e.g., metal grinding). 

1.4 HOW CAN TUNGSTEN ENTER AND 

LEAVE MY BODY? 

Tungsten can enter your body from the food you eat 

or the water you drink, from the air you breathe, or 

from contact with the skin. When you eat, drink, 

breathe, or touch things containing tungsten 

compounds that can easily be dissolved in water, 

tungsten enters your blood and is carried to all parts 

of your body. Most of the tungsten that enters your 

blood is rapidly released from your body in the 

urine. When you eat or drink things containing 

tungsten, much of the tungsten passes through your 

digestive system and is released from your body in 

the feces. When you breathe air that contains 

tungsten, some of the tungsten moves quickly to 

your bloodstream from the lungs, and some of the 

tungsten is cleared from your lungs in mucus that is 

either swallowed or spit out. When you swallow 

DEPARTMENT of HEALTH AND HUMAN SERVICES, Public Health Service
 

Agency for Toxic Substances and Disease Registry 

www.atsdr.cdc.gov/ Telephone: 1-888-422-8737 Fax: 770-488-4178 E-Mail: atsdric@cdc.gov 
 

 

 

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PUBLIC HEALTH STATEMENT 

Tungsten 

CAS#: 7440-33-7 

Division of Toxicology August 2005 

tungsten that was first in your lungs, it passes 

through your digestive system as if you had eaten it. 

Some enters your blood from your digestive system 

and some passes out with the feces. A small portion 

of the tungsten that enters your blood may spend 

some time in bone, fingernails, or hair. Some of 

this tungsten is slowly eliminated from your body 

through the urine and feces. 

1.5 HOW CAN TUNGSTEN AFFECT MY 

HEALTH? 

Scientists use many tests to protect the public from 

harmful effects of toxic chemicals and to find ways 

for treating persons who have been harmed. 

One way to learn whether a chemical will harm 

people is to determine how the body absorbs, uses, 

and releases the chemical. For some chemicals, 

animal testing may be necessary. Animal testing 

may also help identify health effects such as cancer 

or birth defects. Without laboratory animals, 

scientists would lose a basic method for getting 

information needed to make wise decisions that 

protect public health. Scientists have the 

responsibility to treat research animals with care 

and compassion. Scientists must comply with strict 

animal care guidelines because laws today protect 

the welfare of research animals. 

You are not likely to experience any health effects 

that would be related to exposure to tungsten or 

tungsten compounds. Tungsten compounds have 

caused breathing problems and changed behavior in 

some animals given very large amounts of tungsten 

compounds, but you are not likely to be exposed to 

amounts of tungsten in the air you breathe or the 

food or water you take into your body that would be 

large enough to cause similar effects. If you are a 

worker who has inhaled tungsten heavy metal dust, 

your exposure would help determine if health 

effects similar to those seen in animals might occur. 

1.6 HOW CAN TUNGSTEN AFFECT 

CHILDREN? 

This section discusses potential health effects in 

humans from exposures during the period from 

conception to maturity at 18 years of age. 

Children could be affected in the same ways as 

adults. In adult animals, very large amounts of 

tungsten compounds have been shown to cause 

breathing problems and changes in behavior. 

However, it is not likely that children would be 

exposed to amounts of tungsten in the air they 

breathe or the food or water they consume that 

would be large enough to cause effects similar to 

those that were seen in the animals. Animal studies 

have shown that tungsten in the blood of a pregnant 

mother can enter the blood of a fetus in the womb. 

Studies in dairy cows have shown that tungsten may 

also enter the milk. There is no information to 

suggest that the effects seen in animals could not 

occur in humans. We do not know whether unborn 

babies, babies, and children might differ from adults 

in their susceptibility to health effects from 

exposure to tungsten or tungsten compounds. 

DEPARTMENT of HEALTH AND HUMAN SERVICES, Public Health Service
 

Agency for Toxic Substances and Disease Registry 

www.atsdr.cdc.gov/ Telephone: 1-888-422-8737 Fax: 770-488-4178 E-Mail: atsdric@cdc.gov 
 

 

 

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PUBLIC HEALTH STATEMENT 

Tungsten 

CAS#: 7440-33-7 

Division of Toxicology August 2005 

1.7 HOW CAN FAMILIES REDUCE THE 

RISK OF EXPOSURE TO TUNGSTEN? 

If your doctor finds that you have been exposed to 

substantial amounts of tungsten, ask whether your 

children might also have been exposed. Your 

doctor might need to ask your state health 

department to investigate. 

Children living near waste sites containing tungsten 

are likely to be exposed to higher environmental 

levels of tungsten through breathing contaminated 

air, drinking contaminated water, touching soil, and 

eating contaminated soil. Children sometimes eat 

dirt, which should be discouraged. Parents should 

supervise to see that children wash their hands 

frequently and before eating. Parents should 

consult their family physicians about whether (and 

how) hand-to-mouth behaviors in their children 

might be discouraged. If your community’s 

drinking water has been reported to contain elevated 

levels of tungsten, you should take advantage of 

alternative water sources such as bottled water for 

drinking. Some children may be exposed to 

tungsten by contact with a family member who 

works in a facility using tungsten or who works 

with tungsten carbide grinding wheels. If you work 

at a facility that uses tungsten or have tungsten dust 

on your clothes, change your clothes and clean your 

hair and skin before leaving your job or work site 

and returning home. Do not bring objects home 

such as work tools that may be contaminated with 

tungsten. 

1.8 IS THERE A MEDICAL TEST TO 

DETERMINE WHETHER I HAVE BEEN 

EXPOSED TO TUNGSTEN? 

Medical tests exist that can determine whether your 

body fluids contain high levels of tungsten. 

Samples of blood or feces can be collected in a 

doctor's office and sent to a laboratory that can 

measure tungsten levels. It is easier for most 

laboratories to measure tungsten in blood than in 

feces. The presence of high levels of tungsten in 

the feces can mean recent high tungsten exposure. 

High levels of tungsten in the blood can mean high 

tungsten consumption and/or high exposure. High 

tungsten levels in blood or feces reflect the level of 

exposure to tungsten. Measuring tungsten levels in 

urine and saliva also may provide information about 

tungsten exposure. Tests to measure tungsten in 

hair may provide information on long-term tungsten 

exposure. 

1.9 WHAT RECOMMENDATIONS HAS THE 

FEDERAL GOVERNMENT MADE TO 

PROTECT HUMAN HEALTH? 

The federal government develops regulations and 

recommendations to protect public health. 

Regulations can be enforced by law. The EPA, the 

Occupational Safety and Health Administration 

(OSHA), and the Food and Drug Administration 

(FDA) are some federal agencies that develop 

regulations for toxic substances. Recommendations 

provide valuable guidelines to protect public health, 

but cannot be enforced by law. The Agency for 

Toxic Substances and Disease Registry (ATSDR) 

and the National Institute for Occupational Safety 

DEPARTMENT of HEALTH AND HUMAN SERVICES, Public Health Service
 

Agency for Toxic Substances and Disease Registry 

www.atsdr.cdc.gov/ Telephone: 1-888-422-8737 Fax: 770-488-4178 E-Mail: atsdric@cdc.gov 
 

 

 

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PUBLIC HEALTH STATEMENT 

Tungsten 

CAS#: 7440-33-7 

Division of Toxicology August 2005 

and Health (NIOSH) are two federal organizations 

that develop recommendations for toxic substances. 

Regulations and recommendations can be expressed 

as “not-to-exceed” levels, that is, levels of a toxic 

substance in air, water, soil, or food that do not 

exceed a critical value that is usually based on 

levels that affect animals; they are then adjusted to 

levels that will help protect humans. Sometimes 

these not-to-exceed levels differ among federal 

organizations because they used different exposure 

times (an 8-hour workday or a 24-hour day), 

different animal studies, or other factors. 

Recommendations and regulations are also updated 

periodically as more information becomes available. 

For the most current information, check with the 

federal agency or organization that provides it. 

Some regulations and recommendations for 

tungsten include the following: 

There are few guidelines for tungsten and tungsten 

compounds. For tungsten and insoluble tungsten 

compounds, NIOSH has established a 

recommended exposure limit (REL; 10-hour time 

weighted average) of 5 mg/m3

 and a short-term 

exposure limit (STEL; 15-minute time weighted 

average) of 10 mg/m3

. OSHA has established 

permissible exposure limits (PELs; 8-hour time 

weighted average) for tungsten of 5 mg/m3 

(insoluble compounds) and 1 mg/m3

 (soluble 

compounds) for construction and shipyard 

industries. 

1.10 WHERE CAN I GET MORE 

INFORMATION? 

If you have any more questions or concerns, please 

contact your community or state health or 

environmental quality department, your regional 

Nuclear Regulatory Commission office, or contact 

ATSDR at the address and phone number below. 

ATSDR can also tell you the location of 

occupational and environmental health clinics. 

These clinics specialize in recognizing, evaluating, 

and treating illnesses resulting from exposure to 

hazardous substances. 

Toxicological profiles are also available on-line at 

www.atsdr.cdc.gov and on CD-ROM. You may 

request a copy of the ATSDR ToxProfiles 

CD-ROM by calling the information and technical 

assistance toll-free number at 1-888-42ATSDR 

(1-888-422-8737), by email at atsdric@cdc.gov, or 

by writing to: 

Agency for Toxic Substances and Disease Registry 

Division of Toxicology 

1600 Clifton Road NE 

 Mailstop F-32 

Atlanta, GA 30333 

 Fax: 1-770-488-4178 

For-profit organizations may request a copy of final 

profiles from the following: 

National Technical Information Service (NTIS) 

5285 Port Royal Road 

Springfield, VA 22161 

Phone: 1-800-553-6847 or 1-703-605-6000 

Web site: http://www.ntis.gov/ 

DEPARTMENT of HEALTH AND HUMAN SERVICES, Public Health Service
 

Agency for Toxic Substances and Disease Registry 

www.atsdr.cdc.gov/ Telephone: 1-888-422-8737 Fax: 770-488-4178 E-Mail: atsdric@cdc.gov