PUBLIC HEALTH STATEMENT

 Boron

Division of Toxicology and Environmental Medicine November 2010

______________________________________________________________________________

DEPARTMENT of HEALTH AND HUMAN SERVICES, Public Health Service

Agency for Toxic Substances and Disease Registry

www.atsdr.cdc.gov/ Telephone: 1-800-232-4636 Fax: 770-488-4178 E-Mail: cdcinfo@cdc.gov

This Public Health Statement is the summary chapter from the Toxicological Profile for Boron. 

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 

1-800-232-4636.

____________________________________________________________________________________

This public health statement tells you about boron 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. Boron and boron compounds have been found in at least 

164 of the 1,699 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 boron 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 boron, 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.
 PUBLIC HEALTH STATEMENT

 Boron

Division of Toxicology and Environmental Medicine November 2010

______________________________________________________________________________

DEPARTMENT of HEALTH AND HUMAN SERVICES, Public Health Service

Agency for Toxic Substances and Disease Registry

www.atsdr.cdc.gov/ Telephone: 1-800-232-4636 Fax: 770-488-4178 E-Mail: cdcinfo@cdc.gov

1.1 WHAT IS BORON?

Naturally 

occurring 

Boron is a widely occurring element in minerals found in the earth’s crust. It 

is the 51st most common element found in the earth’s crust and is found at 

an average concentration of 8 mg/kg (approximately 0.0008%).

 

Combines with 

oxygen to form 

borates

Boron is found in the environment primarily combined with oxygen in 

compounds called borates. Common borate compounds include:

• boric acid 

• sodium tetraborates (also referred to as borax)

• boron oxide 

Used to 

manufacture 

industrial and 

consumer 

products

Borate-containing minerals are mined and processed to produce borates for 

several industrial uses in the United States including:

• glass and ceramics

• soaps and detergents

• fire retardants 

• pesticides

1.2 WHAT HAPPENS TO BORON WHEN IT ENTERS THE ENVIRONMENT?

Released into 

air, water, and 

soil 

Boron can be released into air, water, or soil after natural weathering of soils 

and rocks. 

Smaller amounts of boron can be released from: 

• glass manufacturing plants 

• coal-burning power plants

• copper smelters

• agricultural fertilizer and pesticide usage.

Is not broken 

down 

Boron cannot be destroyed in the environment. It can only change its form or

become attached or separated from particles in soil, sediment, and water.
 PUBLIC HEALTH STATEMENT

 Boron

Division of Toxicology and Environmental Medicine November 2010

______________________________________________________________________________

DEPARTMENT of HEALTH AND HUMAN SERVICES, Public Health Service

Agency for Toxic Substances and Disease Registry

www.atsdr.cdc.gov/ Telephone: 1-800-232-4636 Fax: 770-488-4178 E-Mail: cdcinfo@cdc.gov

1.3 HOW MIGHT I BE EXPOSED TO BORON?

Food You can be exposed to boron in food, mainly vegetables and fruits, as boron 

is an essential element in plants. The average daily intake of boron for 

adults is 1 milligram.

Water Boron is widely distributed in surface water and groundwater. 

• the average surface water concentration is about 0.1 mg per liter 

(mg/L)

• boron concentrations in groundwater can be as high as 300 mg/L in 

areas with natural boron-rich deposits 

• concentrations up to 0.4 mg/L have been found in most drinking 

water samples

Soil Average concentrations of 26 and 33 mg per kilogram (mg/kg) have been 

reported in soil.

Air The general public is not likely to be exposed to air contaminated with boron. 

The average level of boron in air samples is 0.00005 mg boron per cubic 

meter of air (mg boron/m3

).

 

Workplace air In workplaces that mine and process borates, boron concentrations in dusty 

air samples have been reported to range from about 0.5 to 3 mg boron/m3.

Consumer 

products

Boric acid, anhydrous sodium tetraborate, and sodium tetraborate 

decahydrate (borax) are found in consumer products such as:

• laundry detergent

• pesticides

• facial creams and cleaners 

• plant foods

• household cleaners

1.4 HOW CAN BORON ENTER AND LEAVE MY BODY?

Most ingested 

boron is 

absorbed 

Boron can enter your body when you eat food (fruits and vegetables), drink 

water containing it, when you breathe borate dust in the air, and when 

damaged skin comes in contact with it.

 
 PUBLIC HEALTH STATEMENT

 Boron

Division of Toxicology and Environmental Medicine November 2010

______________________________________________________________________________

DEPARTMENT of HEALTH AND HUMAN SERVICES, Public Health Service

Agency for Toxic Substances and Disease Registry

www.atsdr.cdc.gov/ Telephone: 1-800-232-4636 Fax: 770-488-4178 E-Mail: cdcinfo@cdc.gov

Typically leaves 

your body within 

4 days

Most of the boron leaves the body in urine. 

Over half of the boron taken by mouth can be found in urine within 24 hours 

and the other half can be detected in urine for up to 4 days

 

1.5 HOW CAN BORON AFFECT MY HEALTH?

This section looks at studies concerning potential health effects in animal and humans studies.

Exposure in air People working in dusty workplaces where borates are mined and 

processed have reported irritation of the nose, throat, and eyes. The 

irritation does not persist for long periods after leaving the dusty area.

Exposure by 

ingestion

• Humans

• Animals

Exposure to large amounts of boron (about 30 g of boric acid) over short 

periods of time can affect the stomach, intestines, liver, kidney, and brain 

and can eventually lead to death. 

Studies of dogs, rats, and mice indicate that the male reproductive organs, 

especially the testes, are affected if large amounts of boron are ingested for 

short or long periods of time. The doses that produced these effects in 

animals are more than 1,800 times higher than the average daily intake of 

boron in food by adults in the U.S. population.

No evidence of cancer was found in a study in which mice were given boric 

acid in the diet throughout their lifetime.

1.6 HOW CAN BORON 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 likely 

to have similar 

effects as adults

It is likely that children would show the same health effects as adults. We 

do not know whether children differ in their susceptibility to the effects of 

boron.
 PUBLIC HEALTH STATEMENT

 Boron

Division of Toxicology and Environmental Medicine November 2010

______________________________________________________________________________

DEPARTMENT of HEALTH AND HUMAN SERVICES, Public Health Service

Agency for Toxic Substances and Disease Registry

www.atsdr.cdc.gov/ Telephone: 1-800-232-4636 Fax: 770-488-4178 E-Mail: cdcinfo@cdc.gov

Birth defects We do not know whether boron causes birth defects in people. Low birth 

weights, birth defects, and developmental delays have occurred in newborn 

animals whose mothers were orally exposed to high doses of boron (as 

boric acid). The doses that produced these effects in pregnant animals are 

more than 800 times higher than the average daily intake of boron in food 

by adult women in the U.S. population.

1.7 HOW CAN FAMILIES REDUCE THE RISK OF EXPOSURE TO BORON?

Limit children’s 

exposure to 

pesticides

Pesticides containing boron compounds should be used according to their 

directions and should be kept away from children. 

Store household 

chemicals out of 

reach of young 

children

Always store household chemicals in their original labeled containers out of 

reach of young children to prevent accidental poisonings. Never store 

household chemicals in containers children would find attractive to eat or 

drink from, such as old soda bottles. 

Discourage 

children from 

eating dirt or 

putting hands in 

their mouth while 

playing with dirt

Children living near waste sites containing boron and boron compounds are 

likely to be exposed to higher than normal environmental levels of boron 

through breathing in boron-containing dust, and touching and eating 

contaminated soil.

Children should be encouraged to wash their hands frequently, especially 

before eating.

1.8 IS THERE A MEDICAL TEST TO DETERMINE WHETHER I HAVE BEEN 

EXPOSED TO BORON?

Can be measured 

in blood and urine 

Blood and urine can be examined to determine whether excessive 

exposure to boron has occurred. 

The detection of boron in the blood or urine cannot be used to predict the 

kind of health effects that might develop from that exposure.
 PUBLIC HEALTH STATEMENT

 Boron

Division of Toxicology and Environmental Medicine November 2010

______________________________________________________________________________

DEPARTMENT of HEALTH AND HUMAN SERVICES, Public Health Service

Agency for Toxic Substances and Disease Registry

www.atsdr.cdc.gov/ Telephone: 1-800-232-4636 Fax: 770-488-4178 E-Mail: cdcinfo@cdc.gov

1.9 WHAT RECOMMENDATION 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.
 PUBLIC HEALTH STATEMENT

 Boron

Division of Toxicology and Environmental Medicine November 2010

______________________________________________________________________________

DEPARTMENT of HEALTH AND HUMAN SERVICES, Public Health Service

Agency for Toxic Substances and Disease Registry

www.atsdr.cdc.gov/ Telephone: 1-800-232-4636 Fax: 770-488-4178 E-Mail: cdcinfo@cdc.gov

Some regulations and recommendations for boron include the following:

Levels in drinking 

water set by EPA

The EPA has determined that exposure to boron in drinking water at 

concentrations of 4 mg/L for one day or 0.9 mg/L for 10 days is not 

expected to cause any adverse effects in a child.

The EPA has determined that lifetime exposure to 1 mg/L boron is not 

expected to cause any adverse effects.

Levels in 

workplace air set 

by OSHA

OSHA set a legal limit of 15 mg/m3 for boron oxide in air averaged over an 

8-hour work day.

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, 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 that result 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 toll-free information 

and technical assistance number at 1-800-CDCINFO (1-800-232-4636), by e-mail at 

cdcinfo@cdc.gov, or by writing to: 
 PUBLIC HEALTH STATEMENT

 Boron

Division of Toxicology and Environmental Medicine November 2010

______________________________________________________________________________

DEPARTMENT of HEALTH AND HUMAN SERVICES, Public Health Service

Agency for Toxic Substances and Disease Registry

www.atsdr.cdc.gov/ Telephone: 1-800-232-4636 Fax: 770-488-4178 E-Mail: cdcinfo@cdc.gov

Agency for Toxic Substances and Disease Registry

Division of Toxicology and Environmental Medicine

1600 Clifton Road NE

Mailstop F-62

Atlanta, GA 30333

Fax: 1-770-488-4178

Organizations for-profit may request copies of final Toxicological 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/