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PUBLIC HEALTH STATEMENT 

Polybrominated Biphenyls 

Division of Toxicology September 2004 

This Public Health Statement is the summary 

chapter from the Toxicological Profile for 

Polybrominated Biphenyls and Polybrominated 

Diphenyl Ethers. 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 these substances 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 

polybrominated biphenyls (PBBs) and the effects of 

exposure to PBBs. 

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. PBBs have 

been found in at least nine of the 1,647 current or 

former NPL sites. Although the total number of 

NPL sites evaluated for these substances is not 

known, the possibility exists that the number of 

sites at which PBBs are 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 these substances 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 PBBs, 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 

PBBs. 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 ARE PBBs? 

Polybrominated biphenyls (PBBs) are chemicals 

that were added to plastics used in a variety of 

consumer products, such as computer monitors, 

televisions, textiles, and plastic foams, to make 

them difficult to burn. Because PBBs were mixed 

into plastics rather than bound to them, they were 

able to leave the plastic and find their way into the 

environment. Commercial production of PBBs 

began in the 1970s. Manufacture of PBBs was 

discontinued in the United States in 1976. Concern 

regarding PBBs is mainly related to exposures 

resulting from an agriculture contamination episode 

that occurred in Michigan over a 10-month period 

during 1973–1974. 

There are no known natural sources of PBBs in the 

environment. PBBs are solids and are colorless to 

off-white. PBBs enter the environment as mixtures 

containing a variety of individual brominated 

biphenyl (for PBBs) components, known as 

congeners. Some commercial PBB mixtures are 

known in the United States under the industrial 

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 

Polybrominated Biphenyls 

Division of Toxicology September 2004 

trade name, FireMaster®. However, other flame 

retardant chemicals also may be identified by this 

name. PBBs are no longer used in North America 

because the agriculture contamination episode that 

occurred in Michigan in 1973–1974 led to the 

cessation of its production. 

1.2 WHAT HAPPENS TO PBBs WHEN 

THEY ENTER THE ENVIRONMENT? 

In the past, PBBs entered the air, water, and soil 

during their manufacture and use. In addition, 

animal feed was accidentally mixed with 500– 

1,000 pounds of PBBs in lower Michigan in 1973. 

This contamination of the food chain affected 

millions of farm animals and humans living in 

Michigan at this time. PBBs entered the 

environment during the disposal of contaminated 

animal feed and animal products during the 

agriculture contamination episode. PBBs also 

entered the environment from PBB-containing 

wastes that manufacturers disposed of in waste 

sites. Small quantities of PBBs also entered the 

environment from accidental spills during transport. 

PBBs are no longer manufactured in North 

America, but very small amounts of PBBs may be 

released into the environment from poorly 

maintained hazardous waste sites and improper 

incineration of plastics that contain PBBs. 

1.3 HOW MIGHT I BE EXPOSED TO PBBs? 

PBBs are no longer produced or used in the United 

States. Thus, the general population exposure to 

PBBs will only be from past releases. For people 

living in the lower peninsula of Michigan, 

especially near PBB contaminated areas, exposure 

to PBBs may still be occurring today. However, 

environmental levels have decreased since the 

1970s and current exposure, if any, will be at low 

levels. For other regions of the United States, the 

levels of exposure will either be very low or none. 

Measured data in air, water, soil, and food, as well 

as body burden data (blood, urine, breast milk, and 

body fat), indicate that most people within the state 

of Michigan who were exposed to PBBs received 

very low levels of PBBs. The levels from exposure 

were slightly higher for people living in the lower 

peninsula of Michigan and highest among people 

living on contaminated dairy farms. Consumption 

of contaminated meat and dairy products caused the 

higher levels of PBBs in the body. Monitoring of 

the workplace environment, as well as the blood, 

urine, and body fat of workers indicated that those 

in PBB industries were exposed to higher levels of 

PBBs than the general population. These workers 

were exposed to PBBs by breathing contaminated 

workplace air and by skin contact with PBBs. 

Occupational exposure also could have occurred 

from the incineration of materials containing PBBs. 

Exposure in workplaces is no longer likely because 

PBBs are no longer manufactured. People who live 

near hazardous waste sites that contain PBBs may 

be exposed primarily by breathing air that contains 

PBBs. 

1.4 HOW CAN PBBs ENTER AND LEAVE 

MY BODY? 

If you breathe air that contains PBBs, or swallow 

food, water, or soil contaminated with PBBs, they 

can enter your body through your lungs and 

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 

Polybrominated Biphenyls 

Division of Toxicology September 2004 

stomach and pass into the bloodstream. We don’t 

know how much of the PBBs will pass into the 

blood from the lungs; although most will probably 

pass into the blood from the stomach and intestines. 

If you touch soil containing PBBs, it is highly 

unlikely that PBBs would pass through your skin 

into the bloodstream. It is not known how fast 

PBBs enter the blood from the lungs or stomach. 

There are no known current sources of PBBs 

because they are no longer produced and used in 

North America. They are rarely found in air and 

drinking water away from production plants and 

contaminated sites. Once PBBs are in your body, 

they can partially change into breakdown products 

called metabolites. Some metabolites and 

unchanged PBBs could leave your body, mainly in 

the feces and in very small amounts in the urine, 

within a few days. Other unchanged PBBs might 

stay in your body for many years. PBBs are stored 

mainly in your body fat, tend to concentrate in 

breast milk fat, and can enter the bodies of children 

through breast feeding. PBBs also can enter the 

bodies of unborn babies through the placenta. 

1.5 HOW CAN PBBs 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. That sometimes involves 

animal testing. Animal testing may 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. 

Much of what is known about the health effects of 

PBBs in people comes from studies of ingestion in 

Michigan in the early-to-mid 1970s, where feed for 

farm animals was accidentally contaminated with a 

fire retardant containing PBBs. People were 

exposed to PBBs for several months when they ate 

meat, milk, and eggs from the contaminated 

animals. After news of the contamination episode 

became widespread, many Michigan residents 

complained of various health problems, including 

nausea, abdominal pain, loss of appetite, joint pain, 

fatigue, and weakness. However, it could not be 

clearly established that any of the problems were 

caused by eating the food contaminated with PBBs. 

PBBs also did not cause any definite changes in the 

livers or immune systems of the Michigan residents. 

However, some people who ate the contaminated 

food developed skin disorders, such as acne and 

hair loss. It is likely that PBBs caused the skin 

problems because other chemicals similar to PBBs 

also cause these effects. Workers who were 

exposed to PBBs for a few days to months by 

breathing and skin contact also developed acne, 

although not all persons exposed to PBBs 

developed acne. Very little is known about the 

health of people who are exposed to low levels of 

PBBs for long periods by eating, breathing, or skin 

contact. 

Laboratory animals fed PBBs had body weight loss, 

skin disorders, and nervous system effects, and their 

livers, kidneys, thyroid glands, and immune systems 

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 

Polybrominated Biphenyls 

Division of Toxicology September 2004 

were seriously injured. Some animals fed high 

amounts died. PBBs also caused birth defects in 

animals, but it is not known for sure whether PBBs 

make males or females infertile. Most of the effects 

in animals occurred after they ate large amounts of 

PBBs for short periods or smaller amounts for 

several weeks or months. Body weight loss and 

effects on the livers, kidneys, and thyroid glands 

were observed. A lifetime study of rats and mice 

fed PBBs at doses higher than those expected from 

environmental exposure. A few studies tested 

animals exposed to PBBs by skin contact. These 

animals had injuries to the liver and skin. Only one 

study tested animals exposed to PBBs by breathing, 

and no health effects were observed. 

We do not know if PBBs caused or will cause 

cancer in people who ate food contaminated with 

PBBs. Rats developed cancer in their livers after 

eating a large amount of a PBB mixture only once. 

The babies of exposed rats developed cancer in their 

livers after eating a large amount of the same PBB 

mixture only once. Liver cancer also developed in 

rats and mice that ate smaller amounts of the PBB 

mixture for several months. Mice that had skin 

contact with a small amount of a PBB mixture for 

several months did not develop skin cancer. There 

are no cancer studies in animals that breathed PBBs. 

Because animals fed PBBs did develop cancer, the 

National Toxicology Program (NTP) of the 

Department of Health and Human Services (DHHS) 

determined that PBBs may reasonably be 

anticipated to be carcinogens. Similarly, the 

International Agency for Research on Cancer 

(IARC) has determined that PBBs are possibly 

carcinogenic to humans. The EPA has not 

classified the carcinogenicity of PBBs. 

We do not know whether the effects found in 

animals exposed to PBBs would also occur in 

people exposed in the same way. The amounts of 

PBBs that caused health effects in animals are much 

greater than levels of PBBs normally found in the 

environment. Long-term exposure to these 

chemicals has a greater potential to cause health 

effects than does short-term exposure to low levels 

because they tend to build up in your body over 

many years. 

1.6 HOW CAN PBBs 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 are exposed to PBBs in generally the same 

way as are adults, mainly by eating contaminated 

food. Because of their smaller weight, children’s 

intake of PBBs per kilogram (or pound) of body 

weight may be greater than that of adults. The most 

likely way that infants will be exposed is from 

breast milk that contains PBBs, although fetuses in 

the womb are also exposed. Children who live near 

hazardous waste sites might accidentally eat some 

PBBs by putting dirty hands or other soil/dirtcovered objects in their mouths, by eating without 

washing their hands, or similar behavior. Some 

children also eat dirt on purpose. It is not possible 

that children could be exposed to PBBs following 

transport of the chemical on clothing from the 

parent’s workplace to the home because PBBs are 

no longer being produced or used. 

Some information on health effects of PBBs in 

children is available from studies of the Michigan 

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 

Polybrominated Biphenyls 

Division of Toxicology September 2004 

contamination episode. Symptoms of ill health 

were not associated with increased exposure to 

PBBs, and general neurological examinations did 

not show any abnormalities. More detailed studies 

of physical and neuropsychological development 

showed no effects that were clearly related to PBBs 

among Michigan children exposed during the 

episode. Changes in nerve and brain function have 

been seen in animals that were exposed to PBBs in 

the womb and by nursing. Animal studies also 

found that exposure to PBBs during pregnancy or 

lactation caused changes in thyroid hormone levels 

in the newborn animals and, at high doses, increases 

in prenatal death and structural birth defects. 

As indicated above, children can be exposed to 

PBBs before birth and from breast milk. PBBs are 

stored in the mother’s body and can be released 

during pregnancy, cross the placenta, and enter fetal 

tissues. Because PBBs dissolve readily in fat, they 

can accumulate in breast milk fat and be transferred 

to babies and young children. PBBs have been 

found in breast milk; however, in most cases, the 

benefits of breast-feeding outweigh any risks from 

exposure in mother’s milk. You should consult 

your health care provider if you have any concerns 

about PBBs and breast feeding. Because the 

nervous system and thyroid are still developing in 

the fetus and child, the effects of PBBs on these 

target systems might be more profound from 

exposure before and soon after birth. That could 

mean fetuses and children are more susceptible to 

PBBs than are adults. 

1.7 HOW CAN FAMILIES REDUCE THE 

RISK OF EXPOSURE TO PBBs? 

If your doctor finds that you have been exposed to 

substantial amounts of PBBs, ask whether your 

children might also have been exposed. Your 

doctor might need to ask your state health 

department to investigate. 

Because PBBs are no longer produced or used, the 

risk of exposure to these compounds is limited. 

You and your children could be exposed to PBBs 

by eating fish or wildlife caught from contaminated 

locations. Children who live near hazardous waste 

sites should be discouraged from playing in the dirt 

near these sites because they could still contain 

PBBs. Children should also be discouraged from 

eating the dirt, and careful handwashing practices 

should be followed. 

1.8 IS THERE A MEDICAL TEST TO 

DETERMINE WHETHER I HAVE BEEN 

EXPOSED TO PBBs? 

Special tests can determine whether PBBs are in the 

blood, body fat, and breast milk. These are not 

regular or routine clinical tests, but could be ordered 

by a doctor to detect PBBs in people exposed to 

them in the environment and at work. If your PBB 

levels are higher than the normal levels, this will 

show that you have been exposed to high levels of 

the chemicals. However, these measurements 

cannot determine the exact amount or type of PBBs 

that you have been exposed to, or how long you 

have been exposed. Although these tests can 

indicate whether you have been exposed to PBBs to 

a greater extent than the general population, they do 

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 

Polybrominated Biphenyls 

Division of Toxicology September 2004 

not predict whether you will be harmed. Blood tests 

are the easiest, safest, and probably the best method 

for detecting recent or past exposures to large 

amounts of PBBs. Results of such tests should be 

reviewed and carefully interpreted by physicians 

with a background in environmental and 

occupational medicine. Exposures to PBBs have 

been of greatest concern in Michigan as explained 

in Sections 1.3 and 1.5. 

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 

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 PBBs 

include the following: 

At present, there are no federal guidelines or 

recommendations for protecting human health from 

exposure to PBBs. 

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 ToxProfilesTM 

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: 

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 

Polybrominated Biphenyls 

Division of Toxicology September 2004 

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