PUBLIC HEALTH STATEMENT 

 Bromoform and Dibromochloromethane CAS#: 75-25-2 and 124-48-1 

Division of Toxicology August 2005

__________________________________________________________________________________________

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 

This Public Health Statement is the summary 

chapter from the Toxicological Profile for 

Bromoform and Dibromochloromethane. 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 

bromoform and dibromochloromethane and the 

effects of exposure to them. 

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. Bromoform 

and dibromochloromethane has been found in at 

least 140 and 174 of the 1,662 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 

bromoform and dibromochloromethane 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 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 bromoform or 

dichlorobromomethane, 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 

them. 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 BROMOFORM AND 

DIBROMOCHLOROMETHANE? 

Bromoform (also known as tribromomethane) and 

dibromochloromethane are colorless to yellow, 

heavy, nonburnable liquids with a sweetish odor. 

These chemicals are possible contaminants of 

drinking water that has been chlorinated to kill 

bacteria and viruses that could cause serious 

waterborne infectious diseases. Bromoform and 

dibromochloromethane may form when chlorine 

reacts with other naturally occurring substances in 

water, such as decomposing plant material. Plants 

in the ocean also produce small amounts of these 

chemicals. 

These chemicals are found mainly in water that 

originally came from surface sources, such as rivers 

and lakes. Springs and deep drilled wells usually 

contain very little of the substances that react with 

chlorine to form these chemicals; therefore, well 

and spring water is less likely a source of 

bromoform and dibromochloromethane than water 
 PUBLIC HEALTH STATEMENT 

 Bromoform and Dibromochloromethane CAS#: 75-25-2 and 124-48-1 

Division of Toxicology August 2005

__________________________________________________________________________________________

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 

from a reservoir (artificial lake). The amount of 

bromoform and dibromochloromethane in drinking 

water can change considerably from day to day, 

depending on the source, temperature, amount of 

plant material in the water, amount of chlorine 

added, and a variety of other factors. 

In the past, bromoform was used by industry to 

dissolve dirt and grease and to make other 

chemicals. It was also used in the early part of this 

century as a medicine to help children with 

whooping cough get to sleep. Currently, 

bromoform is only produced in small amounts for 

use in laboratories and in geological and electronics 

testing. Dibromochloromethane was used in the 

past to make other chemicals such as fire 

extinguisher fluids, spray can propellants, 

refrigerator fluid, and pesticides. It is now only 

used on a small scale in laboratories. 

In the environment, bromoform and 

dibromochloromethane are not found as pure 

liquids, but instead, they are found either dissolved 

in water or evaporated into air as a gas. Both 

bromoform and dibromochloromethane are 

relatively stable in the air, but reactions with other 

chemicals in the air cause them to break down 

slowly (about 50% in 1 or 2 months). Bromoform 

and dibromochloromethane in water or soil may 

also be broken down by bacteria, but the speed of 

this process is not known. 

1.2 WHAT HAPPENS TO BROMOFORM 

AND DIBROMOCHLOROMETHANE 

WHEN THEY ENTER THE 

ENVIRONMENT? 

Bromoform and dibromochloromethane enter the 

environment through the disposal of water that has 

been disinfected with chlorine or as vapors emitted 

from chlorinated water. These chemicals are also 

made naturally by plant-like organisms called algae 

that are found in the oceans. Some part of 

bromoform and dibromochloromethane that enters 

the air is removed by rain. What is left in the air 

takes about 1–2 months for half of it to degrade. In 

water, bromoform and dibromochloromethane are 

slowly broken down at the water surface where 

oxygen is available, but break down much faster in 

deep water and in water that is underground where 

there is a lot less oxygen. Bromoform and 

dibromochloromethane are mobile in soils and may 

seep into groundwater. Bromoform and 

dibromochloromethane do not appear to concentrate 

in fish. 

1.3 HOW MIGHT I BE EXPOSED TO 

BROMOFORM AND 

DIBROMOCHLOROMETHANE? 

You are most likely to be exposed to bromoform 

and dibromochloromethane by drinking water that 

has been treated with chlorine. Usually, the levels 

in chlorinated drinking water are between 1 and 

10 parts of bromoform and dibromochloromethane 

per billion parts of water (ppb). These are levels 

that are known to be without adverse health effects. 

Bromoform and dibromochloromethane have also 

been detected in chlorinated swimming pools. 
 PUBLIC HEALTH STATEMENT 

 Bromoform and Dibromochloromethane CAS#: 75-25-2 and 124-48-1 

Division of Toxicology August 2005

__________________________________________________________________________________________

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 

Exposure can occur at a swimming pool, by 

breathing bromoform or dibromochloromethane that 

has evaporated into the air, or by uptake from the 

water through the skin. Neither 

dibromochloromethane nor bromoform are likely to 

be found in food. 

If you live near a factory or laboratory that makes or 

uses dibromochloromethane or bromoform, you 

might be exposed to dibromochloromethane or 

bromoform in the air. Currently, bromoform is only 

used for geological and electronics testing. 

Dibromochloromethane is used on a small-scale in 

laboratories. Since neither dibromochloromethane 

nor bromoform have widespread use in this country, 

they are usually present in outside air at very low 

levels (less than 0.01 ppb). Therefore, exposure to 

bromoform or dibromochloromethane in the air is a 

minor route. Exposure may occur if you come into 

contact with water or soil at a chemical waste site 

where dibromochloromethane or bromoform has 

been disposed. 

1.4 HOW CAN BROMOFORM AND 

DIBROMOCHLOROMETHANE ENTER 

AND LEAVE MY BODY? 

Studies in animals or humans indicate that both 

bromoform and dibromochloromethane can easily 

enter your body after swallowing them in water or 

breathing them in air. They can also enter your 

body through your skin (for example, by washing or 

showering in water containing these chemicals). 

Some portion of bromoform and 

dibromochloromethane entering your body may be 

broken down to other compounds. Bromoform, 

dibromochloromethane, and their breakdown 

products can be removed from the body by being 

exhaled from the lungs. These chemicals leave the 

body fairly rapidly. Bromoform and 

dibromochlormethane do not tend to build up in the 

body, 50–90% of the amount that enters the body is 

removed within 8 hours. 

1.5 HOW CAN BROMOFORM AND 

DIBROMOCHLOROMETHANE 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. 

The effects of bromoform and dibromochloromethane on your health depend largely on the 

amount you take into your body and the duration of 

exposure. In general, the more you take in, the 

greater the chance that an effect will occur. The 

main effect of swallowing or breathing large 

amounts of bromoform is a slowing of normal brain 

activities, resulting in sleepiness or sedation 
 PUBLIC HEALTH STATEMENT 

 Bromoform and Dibromochloromethane CAS#: 75-25-2 and 124-48-1 

Division of Toxicology August 2005

__________________________________________________________________________________________

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 

occuring quickly after the chemicals enter your 

body. In humans, these effects tend to disappear 

within a day. Exposures capable of producing these 

effects include swallowing 1–4 drops of liquid 

bromoform, an amount much greater than is usually 

found in a glass of drinking water. At much higher 

amounts, a person may become unconsciousness or 

die. The amount of dibromochloromethane taken 

by mouth that would affect humans is not known, 

but is probably similar to bromoform. 

Some studies in animals indicate that exposure to 

high doses of bromoform or dibromochloromethane 

may also lead to liver and the kidney injury within a 

short period of time. Exposure to low levels of 

bromoform or dibromochloromethane do not appear 

to seriously affect the brain, liver, or kidneys. Other 

animal studies suggest that typical bromoform or 

dibromochloromethane exposures do not pose a 

high risk of affecting the chance of becoming 

pregnant or harming an unborn baby. However, 

studies in animals indicate that long-term intake of 

either bromoform or dibromochloromethane can 

cause liver and kidney cancer. Although cancer in 

humans cannot be definitely attributed to these 

chemicals, it is an effect of special concern, since 

many people are exposed to low levels of 

bromoform and dibromochloromethane in 

chlorinated drinking water. 

The International Agency for Research on Cancer 

(IARC) concluded that bromoform and 

dibromochloromethane are not classifiable as to 

human carcinogenicity. The EPA classified 

bromoform as a probable human carcinogen and 

dibromochloromethane as a possible human 

carcinogen. 

1.6 HOW CAN BROMOFORM AND 

DIBROMOCHLOROMETHANE AFFECT 

CHILDREN? 

This section discusses potential health effects in 

humans from exposures during the period from 

conception to maturity at 18 years of age. 

In the early 1900s, bromoform was given to 

children suffering from whooping cough, resulting 

in several deaths when children were accidentally 

overdosed. Children appeared drowsy, then lifeless, 

just before dying. 

There are no studies in humans or laboratory 

animals that examine whether the effects of 

bromoform and dibromochloromethane change with 

age. Based on current knowledge of body function, 

and metabolism in the body, there is no indication 

that children will be affected more than adults. 

1.7 HOW CAN FAMILIES REDUCE THE 

RISK OF EXPOSURE TO 

BROMOFORM AND 

DIBROMOCHLOROMETHANE? 

If your doctor finds that you have been exposed to 

substantial amounts of bromoform and/or 

dibromochloromethane, ask whether your children 

might also have been exposed. Your doctor might 

need to ask your state health department to 

investigate. 

The chance of consuming bromoform or 

dibromochloromethane in chlorinated public 

drinking water varies with season, water 

temperature, water chemistry, disinfection method, 
 PUBLIC HEALTH STATEMENT 

 Bromoform and Dibromochloromethane CAS#: 75-25-2 and 124-48-1 

Division of Toxicology August 2005

__________________________________________________________________________________________

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 

and other factors. However, the health risks 

associated with drinking non-disinfected water 

when there is evidence of disease-causing 

contamination (i.e., bacteria, viruses, etc.) are much 

greater than the risk of adverse health effects from 

exposure to bromoform or dibromochloromethane. 

There are water treatment methods that people can 

be used in the home to reduce exposure to 

bromoform and dibromochloromethane from 

chlorinated tap water. These include simple do-ityourself methods such as connecting solid carbon 

black filters to faucets and shower taps. 

Homeowners may discuss other home water 

treatment methods, including filtering, aeration or 

boiling, distillation, and/or activated charcoal, with 

a professional plumber or water well contractor. 

The chance of exposure to bromoform and 

dibromochloromethane may be reduced by 

minimizing contact with water expected to have 

higher levels of these chemicals, such as chlorinated 

swimming pool water. When bathing or showering 

some portion of dibromochloromethane and/or 

bromoform may evaporate into the air. Opening 

bathroom windows, and taking shorter baths and 

showers may reduce the amount of chemical vapor 

that is inhaled or absorbed through the skin. 

1.8 IS THERE A MEDICAL TEST TO 

DETERMINE WHETHER I HAVE BEEN 

EXPOSED TO BROMOFORM AND 

DIBROMOCHLOROMETHANE? 

If you are exposed to bromoform or 

dibromochloromethane, measurable levels of the 

chemicals can sometimes be detected in samples of 

your blood, breath, or fat. However, there is not 

enough information at present to use the results of 

such tests to estimate the level of exposure or to 

predict the nature or the severity of any health 

effects that might result. Since special equipment is 

needed, these tests are not routinely performed in 

doctors' offices. Because bromoform and 

dibromochloromethane are quickly eliminated from 

the body, these special laboratory tests are only 

effective in detecting recent exposures (within 1 or 

2 days). 

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 
 PUBLIC HEALTH STATEMENT 

 Bromoform and Dibromochloromethane CAS#: 75-25-2 and 124-48-1 

Division of Toxicology August 2005

__________________________________________________________________________________________

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 

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 

bromoform and dibromochloromethane include the 

following: 

OSHA has set a legally enforceable limit of 0.5 ppm 

for bromoform in workroom air to protect workers 

during an 8-hour shift over a 40-hour work week. 

EPA recommends that drinking water levels for 

bromoform should not be more than 0.7 parts per 

million (ppm) for bromoform and 0.7 ppm for 

dibromochloromethane. 

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/