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PUBLIC HEALTH STATEMENT 

SILVER 

CAS#: 7440-22-4 

Division of Toxicology December 1990 

This Public Health Statement is the summary 

chapter from the Toxicological Profile for Silver. 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 Statement was prepared to give you 

information about silver and to emphasize the 

human health effects that may result from exposure 

to it. The Environmental Protection Agency (EPA) 

has identified 1,177 sites on it's National Priorities 

List (NPL). Silver has been found at 27 of these 

sites However, we do not know how many of the 

1,177 NPL sites have beer evaluated for silver. As 

EPA evaluates more sites, the number of sites a 

which silver is found may change. The information 

is important for you because silver may cause 

harmful health effects and because these sites are 

potential or actual sources of human exposure to 

silver. 

When a chemical is released from a large area, such 

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

drum or bottle, it enters the environment as a 

chemical emission. This emission, which is also 

called a release, does not always lead to exposure. 

You can be exposed to a chemical only when you 

come into contact with the chemical. You may be 

exposed to it in the environment by breathing, 

eating, or drinking substances containing the 

chemical or from skin contact with it. 

If you are exposed to a hazardous substance such as 

silver, several factors will determine whether 

harmful health effects will occur and what the type 

and severity of those health effects will be. These 

factors include the dose (how much), the duration 

(how long), the route or pathway by which you are 

exposed (breathing, eating, drinking, or skin 

contact), the other chemicals to which you are 

exposed, and your individual characteristics such as 

age sex, nutritional status, family traits, life style, 

and state of health. 

1.1 WHAT IS SILVER? 

Silver is one of the basic elements that make up our 

planet. Silver is rare but occurs naturally in the 

environment as a soft, "silver" colored metal 

Because silver is an element, there are no manmade sources of silver People make jewelry, 

silverware, electronic equipment, and dental fillings 

with silver in its metallic form. It also occurs in 

powdery white (silver nitrate and silver chloride) or 

dark-gray to black compounds (silver sulfide and 

silver oxide). Silver could be found at hazardous 

waste sites in the form of these compounds mixed 

with soil and/or water. Therefore, these silver 

compounds will be the main topic of this profile. 

Throughout the profile, the various silver 

compounds will at times be referred to simply as 

silver. 

Photographers use silver compounds to make 

photographs. Photographic materials are the major 

source of the silver that is released into the 

environment. Another source is mines that produce 

silver and other metals. 

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 

SILVER 

CAS#: 7440-22-4 

Division of Toxicology December 1990 

The natural wearing down of silver-bearing rocks 

and soil by the wind and rain also releases large 

amounts of silver into the environment. 

Silver that is released into the environment may be 

carried long distances in air and water. Rain washes 

silver compounds out of many soils so that it 

eventually moves into the groundwater. Silver is 

stable and remains in the environment in one form 

or another until it is taken out again by people. 

Because silver is an element, it does not break 

down, but it can change its form by combining with 

other substances. Over time it may change from the 

form first released, to metallic silver, and then back 

to the same or other compounds. The form it is 

found in depends on environmental conditions. 

1.2 HOW MIGHT I BE EXPOSED TO 

SILVER? 

Most people are exposed daily to very low levels of 

silver mainly in food and drinking water, and less in 

air. The silver in these sources is at least partially 

due to naturally occurring silver in water and soil. 

Skin contact and breathing in air containing silver 

compounds also occurs in the workplace. Other 

sources of exposure include the use of silver in 

medicines, and in activities such as jewelry-making, 

soldering, and photography. Exposure from 

everyday use, such as wearing jewelry or eating 

with silver-coated flatware, is not expected to result 

in silver being taken into the body. 

Silver levels of less than 0.000001 mg silver per 

cubic meter of air (mg/m3), 0.2-2.0 parts silver per 

billion parts water (ppb) in surface waters, such as 

lakes and rivers, and 0.20-0.30 parts silver per 

million parts soil (ppm) in soils are found from 

naturally occurring sources. Silver compounds are 

also found in groundwater and at hazardous waste 

sites throughout the United States. Drinking water 

supplies in the United States have been found to 

contain silver levels of up to 80 ppb. Surveys show 

that one-tenth to one third of samples taken from 

drinking water supplies (both groundwater and 

surface water) contain silver at levels greater than 

30 ppb. 

1.2 HOW CAN SILVER ENTER AND LEAVE 

MY BODY? 

Silver may enter your body through the mouth, 

throat, or digestive tract after eating food or 

drinking water that contains silver, or through your 

lungs after breathing air containing silver. It can 

also enter your body through your skin when you 

put your hands into solutions containing silver 

compounds, such as those used in photography, or 

when you come in contact with silver-containing 

powders. Silver is also known to enter the body 

when medicines containing it are taken or applied to 

the skin or gums. Generally, much less silver will 

enter the body through the skin than through the 

lungs or stomach. 

Because many silver compounds dissolve in water 

and do not evaporate, the most common way that 

silver may enter the body of a person near a 

hazardous waste site is by drinking water that 

contains silver or eating food grown near the site in 

soil that contains silver. Silver can also enter the 

body when soil that has silver in it is eaten. Most of 

the silver that is eaten or breathed in leaves the body 

in the feces within about a week. Very little passes 

through the urine. It is not known how much of the 

silver that enters the body through the skin leaves 

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 

SILVER 

CAS#: 7440-22-4 

Division of Toxicology December 1990 

the body. Some of the silver that is eaten, inhaled, 

or passes through the skin may build up in many 

places in the body. 

1.3 HOW CAN SILVER AFFECT MY 

HEALTH? 

Since at least the early part of this century, doctors 

have known that silver compounds can cause some 

areas of the skin and other body tissues to turn gray 

or blue-gray. Doctors call this condition "argyria." 

Argyria occurs in people who eat or breathe in 

silver compounds over a long period (several 

months to many years). A single exposure to a 

silver compound may also cause silver to be 

deposited in the skin and in other parts of the body; 

however, this is not known to be harmful. It is likely 

that many exposures to silver are necessary to 

develop argyria. Once you have argyria, it is 

permanent. However, the condition is thought to be 

only a "cosmetic" problem. Most doctors and 

scientists believe that the discoloration of the skin 

seen in argyria is the most serious health effect of 

silver. 

Exposure to dust containing relatively high levels of 

silver compounds such as silver nitrate or silver 

oxide may cause breathing problems, lung and 

throat irritation and stomach pain. These effects 

have been seen in workers in chemical 

manufacturing facilities that make silver nitrate and 

silver oxide. One man developed severe breathing 

problems shortly after working with molten silver. 

Skin contact with silver compounds has been found 

to cause mild allergic reactions, such as rash, 

swelling, and inflammation, in some people. 

Studies of the health effects of silver in animals 

commonly use silver nitrate. Doctors and scientists 

assume that effects seen using silver nitrate in 

animals will be very similar to effects in humans 

caused by any silver compound. While this is likely 

to be true, it is still possible that some silver 

compounds will be more harmful, or toxic, than 

silver nitrate. 

One animal study suggests that long-term exposure 

(125 days) to moderately high levels of silver nitrate 

in drinking water may have a slight effect on the 

brain because exposed animals were less active than 

animals drinking water without silver. Another 

study found that some of the animals that drank 

water containing moderately high levels of silver 

for most of their lives (9 months or longer) had 

hearts that were larger than normal. It is not yet 

known whether these effects would occur in 

humans. There have been suggestions in some 

occupational studies in humans that silver can cause 

kidney problems; however, more people exposed to 

silver need to be studied to find out if silver causes 

these effects. 

No studies of cancer or birth defects in animals 

from eating, drinking, or breathing in silver 

compounds were found. Therefore, it is not known 

if these effects would occur in humans. One study 

of animals who drank silver compounds mixed with 

water for most of their lives found no effect on 

fertility. Another study found that reproductive 

tissues were damaged in animals after they received 

injections of silver nitrate. However, the tissue 

recovered even while the animals received more 

injections of silver nitrate. Tests in animals show 

that silver compounds are likely to be lifethreatening for humans only when large amounts 

(that is, grams) are swallowed, and that skin contact 

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 

SILVER 

CAS#: 7440-22-4 

Division of Toxicology December 1990 

with silver compounds is very unlikely to be lifethreatening. 

Silver does have helpful uses. For example, silver 

nitrate was used for many years as drops in 

newborns' eyes to prevent blindness caused by 

gonorrhea, and it is also used in salves for burn 

victims. Some water treatment methods (including 

water filters) also use a form of silver to kill 

bacteria. 

1.4 WHAT LEVELS OF EXPOSURE HAVE 

RESULTED IN HARMFUL HEALTH 

EFFECTS? 

Reports of cases of argyria suggest that gram 

amounts of a silver compound taken in medication 

in small doses over several months may cause 

argyria in some humans. People who work in 

factories that manufacture silver compounds can 

also breathe in the compounds. In the past, some of 

these workers have become argyric. However, the 

level of silver in the air and the length of exposure 

that caused argyria in these workers is not known. It 

is also not known what level of silver causes 

breathing problems, lung and throat irritation, or 

stomach pain in people. Studies in rats show that 

drinking water containing very large amounts of 

silver (2,589 parts of silver per million parts of 

water, or about 2.6 grams per liter) is likely to be 

life-threatening. 

There is very little information about health effects 

following skin contact with silver compounds. 

Argyria that covers the entire body is not seen 

following skin contact with silver compounds, 

although the skin may change color where it 

touches the silver. However, many people who have 

used skin creams containing silver compounds such 

as silver nitrate and silver sulphadiazine have not 

reported health problems from the silver in the 

medicine. In one animal study, a strong solution of 

silver nitrate (81 milligrams silver nitrate per liter of 

water) applied to the skin of guinea pigs for 28 days 

did not cause the animals to die; however, it did 

cause the guinea pigs to stop gaining weight 

normally. It is not known if this would happen to 

people if they were exposed the same way. 

1.5 IS THERE A MEDICAL TEST TO 

DETERMINE WHETHER I HAVE BEEN 

EXPOSED TO SILVER? 

There are reliable and accurate ways of measuring 

silver in the body. Silver can be measured in the 

blood, urine, feces, and body tissues of exposed 

individuals. Because urine and blood samples are 

easy to get, these fluids are most often used to find 

out if a person has been exposed to silver in the last 

week or so. Silver builds up in the body, and the 

best way to learn if past exposure has occurred is to 

look for silver in samples of skin. Tests for silver 

are not commonly done at a doctor's office because 

they require special equipment. Although doctors 

can find out if a person has been exposed to silver 

by having blood or skin samples examined, they 

cannot tell whether any health effects will occur. 

1.7 WHAT RECOMMENDATIONS HAS THE 

FEDERAL GOVERNMENT MADE TO 

PROTECT HUMAN HEALTH? 

The EPA recommends that the concentration of 

silver in drinking water not exceed 0.10 milligrams 

per liter of water (0.10 mg/L) because of the skin 

discoloration that may occur. 

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 

SILVER 

CAS#: 7440-22-4 

Division of Toxicology December 1990 

The EPA requires that spills or accidental releases 

of 1,000 pounds or more of silver be reported to the 

EPA. 

The Occupational Safety and Health Administration 

(OSHA) limits silver in workplace air to 0.01 

milligrams per cubic meter (0.01 mg/m3) for an 8­

hour workday, 40-hour workweek. The National 

Institute of Occupational Safety an Health (NIOSH) 

also recommends that workplace air contain no 

more than 0.01 mg/m3 silver. 

The American Conference of Government 

Industrial Hygienists (ACGIH) recommends that 

workplace air contain no more than 0.1 mg/m3 

silver metal and 0.01 mg/m3 soluble silver 

compounds. 

The federal recommendations have been updated as 

of July 1999. 

1.8 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 or: 

Agency for Toxic Substances and Disease Registry 

Division of Toxicology 

1600 Clifton Road NE, Mailstop F-32 

Atlanta, GA 30333 

Information line and technical assistance: 

Phone: 888-422-8737 

FAX: (770)-488-4178 

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. 

To order toxicological profiles, contact: 

National Technical Information Service 

5285 Port Royal Road 

Springfield, VA 22161 

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

Reference 

Agency for Toxic Substances and Disease Registry 

(ATSDR). 1990. Toxicological profile for silver. 

Atlanta, GA: U.S. Department of Health and 

Human Services, Public Health Service. 

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