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PUBLIC HEALTH STATEMENT 

CHLORDANE 

CAS#: 12789-03-6 

Division of Toxicology May 1994 

This Public Health Statement is the summary 

chapter from the Toxicological Profile for 

Chlordane. 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 chlordane and to emphasize the 

human health effects that may result from exposure 

to it. The Environmental Protection Agency (EPA) 

has identified 1,350 hazardous waste sites as the 

most serious in the nation. These sites comprise the 

"National Priorities List" (NPL): Those sites which 

are targeted for long-term federal cleanup activities. 

Chlordane has been found in at least 176 of the sites 

on the NPL. However, the number of NPL sites 

evaluated for chlordane is not known. As EPA 

evaluates more sites, the number of sites at which 

chlordane is found may increase. This information 

is important because exposure to chlordane may 

cause harmful health effects and because these sites 

are potential or actual sources of human exposure to 

chlordane. 

When a substance 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. This 

release does not always lead to exposure. You can 

be exposed to a substance only when you come in 

contact with it. You can be exposed by breathing, 

eating, drinking, or through skin contact with 

substances containing chlordane. 

If you are exposed to a substance such as chlordane, 

many 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, gender, 

nutritional status, family traits, life-style, and state 

of health. 

1.1 WHAT IS CHLORDANE? 

Chlordane is a man-made chemical that was used as 

a pesticide in the United States from 1948 to 1988. 

It is sometimes referred to by the trade names 

Octachlor® and Velsicol 1068®. It is a thick liquid 

whose color ranges from colorless to amber, 

depending on its purity. It may have no smell or a 

mild, irritating smell. We do not know what it tastes 

like. Chlordane is not a single chemical, but is a 

mixture of many related chemicals, of which about 

10 are major components. Some of the major 

components are trans-chlordane, cis-chlordane, 

beta-chlordene, heptachlor, and trans-nonachlor. 

Chlordane does not dissolve in water. Therefore, 

before it can be used as a spray, it must be placed in 

water with emulsifiers (soap-like substances), which 

results in a milky-looking mixture. 

From 1983 until 1988, chlordane's only approved 

use was to control termites in homes. The pesticide 

was applied underground around the foundation of 

homes. When chlordane is used in the soil around a 

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 

CHLORDANE 

CAS#: 12789-03-6 

Division of Toxicology May 1994 

house, it kills termites that come into contact with 

it. 

Before 1978, chlordane was also used as a pesticide 

on agricultural crops, lawns, and gardens and as a 

fumigating agent. Because of concerns over cancer 

risk, evidence of human exposure and build up in 

body fat, persistence in the environment, and danger 

to wildlife, the EPA canceled the use of chlordane 

on food crops and phased out other above-ground 

uses over the next 5 years. In 1988, when the EPA 

canceled chlordane's use for controlling termites, all 

approved use of chlordane in the United States 

stopped. Manufacture for export continues. 

1.2 WHAT HAPPENS TO CHLORDANE 

WHEN IT ENTERS THE 

ENVIRONMENT? 

When used as a pesticide on crops, on lawns and 

gardens, and to control termites in houses, 

chlordane enters the environment. Although it is no 

longer used in the United States, it may be used in 

other countries. In soil, it attaches strongly to 

particles in the upper layers of soil and is unlikely to 

enter into groundwater. It is not known whether 

chlordane breaks down in most soils. If breakdown 

occurs, it is very slow. Chlordane is known to 

remain in some soils for over 20 years. Persistence 

is greater in heavy, clayey or organic soil than in 

sandy soil. Most chlordane is lost from soil by 

evaporation. Evaporation is more rapid from light, 

sandy soils than from heavy soils. Half of the 

chlordane applied to the soil surface may evaporate 

in 2 to 3 days. Evaporation is much slower after 

chlordane penetrates into the soil. In water, some 

chlordane attaches strongly to sediment and 

particles in the water column and some is lost by 

evaporation. It is not known whether much 

breakdown of chlordane occurs in water or in 

sediment. Chlordane breaks down in the atmosphere 

by reacting with light and with some chemicals in 

the atmosphere. However, it is sufficiently long 

lived that it may travel long distances and be 

deposited on land or in water far from its source. 

Chlordane or the chemicals that chlordane changes 

into accumulate in fish, birds, and mammals. 

Chlordane stays in the environment for many years 

and is still found in food, air, water, and soil. 

Chlordane is still commonly found in some form in 

the fat of fish, birds, mammals, and almost all 

humans. 

1.3 HOW MIGHT I BE EXPOSED TO 

CHLORDANE? 

Everyone in the United States has been exposed to 

low levels of chlordane. A more relevant question is 

whether or not you may have been exposed to high 

levels of chlordane. Before its ban in 1988, you 

might have been exposed to high levels of 

chlordane if you worked in the manufacture, 

formulation, or application of chlordane. Therefore, 

farmers and lawn-care workers may have been 

exposed to chlordane before 1978, and pest control 

workers may have been exposed to chlordane 

before 1988 by skin contact and breathing dust and 

vapor. A national survey conducted from 1980 to 

1983 estimated that 3,732 workers were potentially 

exposed to chlordane in the United States. This 

number of potentially exposed workers should have 

decreased after chlordane's use was banned in the 

United States. However, the ban on chlordane did 

not eliminate it from your environment, and some 

of your opportunities for exposure to chlordane 

continue. 

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 

CHLORDANE 

CAS#: 12789-03-6 

Division of Toxicology May 1994 

Today, people receive the highest exposure to 

chlordane from living in homes that were treated 

with chlordane for termites. Chlordane may be 

found in the air in these homes for many years after 

treatment. Houses in the deep south and southwest 

were most commonly treated. However, chlordane 

use extended from the lower New England States 

south and west to California. Houses built since 

1988 have not been treated with chlordane for 

termite control. You can determine if your home 

was treated with chlordane by examining your 

records or contacting your termite treatment service. 

Over 50 million persons have lived in chlordanetreated homes. Indoor air in the living spaces of 

treated homes have been found to contain average 

levels of between 0.00003 and 0.002 milligram 

(mg) of chlordane in a cubic meter of air (mg/m3). 

However, levels as high as 0.06 mg/m3 have been 

measured in the living areas of these homes. Even 

higher levels are found in basements and crawl 

spaces. 

The most common source of chlordane exposure is 

from ingesting chlordane- contaminated food. 

Chlordane remains in the food supply because much 

of the farmland was treated with chlordane in the 

1960s and 1970s, and it remains in some soil for 

over 20 years. However, since chlordane has been 

banned, the levels in soils would be expected to 

decrease with the passage of time. Chlordane may 

also be found in fish and shellfish caught in 

chlordane-contaminated waters. If you are in doubt 

about whether a lake or river is contaminated, call 

your local Game and Fish or Health departments. 

Chlordane is almost never detected in drinking 

water. A survey conducted by the Food and Drug 

Administration (FDA) determined daily intake of 

chlordane from food to be 0.0013 microgram per 

kilogram of body weight (μg/kg) for infants and 

0.0005-0.0015 μg/kg for teenagers and adults (a 

microgram is one thousandth of a milligram). The 

average adult would, therefore, consume about 0.11 

μg of chlordane. 

You may come into contact with chlordane while 

digging in soil around the foundation of homes 

where it was applied to protect the homes against 

termites. Soil may also be contaminated with 

chlordane around certain NPL hazardous waste 

sites. Chlordane has been found at 176 of 1,350 

hazardous waste sites on the NPL in the United 

States. The highest level of chlordane found in soil 

near an NPL site was 344 ppm. People may be 

exposed to chlordane at these sites by breathing low 

levels of chlordane volatilizing from the soil or 

from touching the soil. Levels of chlordane found in 

groundwater near NPL sites containing chlordane 

ranged from 0.02 to 830 parts of chlordane per 

billion parts of water (ppb). 

Finally, some chlordane may be left over from preban days. Old containers of material thought to 

contain chlordane should be disposed of carefully 

and contact with the skin and breathing vapors 

should be avoided. 

1.4 HOW CAN CHLORDANE ENTER AND 

LEAVE MY BODY? 

Chlordane can enter the body through the skin if 

skin contact occurs with contaminated soils, 

through the lungs if breathed in with contaminated 

air, and through the digestive tract if swallowed. 

Uptake through the skin and digestive tract 

increases if chlordane is in an oily mixture, which 

might occur at hazardous waste sites. The 

importance of each of these ways for chlordane 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 

CHLORDANE 

CAS#: 12789-03-6 

Division of Toxicology May 1994 

enter the body depends on the kind of exposure. For 

example, people living in houses that have been 

treated with chlordane will be exposed mostly by 

breathing the vapor in the air. Workers who sprayed 

chlordane as a pesticide were exposed mostly by 

breathing the compound in the air and by contact 

with the skin. Other people may be exposed to small 

quantities by eating food or drinking water that 

contains chlordane. People at or near waste sites 

may be exposed by touching chlordane in the soil, 

by breathing chlordane that evaporates into the air, 

by drinking water that contains chlordane or by 

eating contaminated fish or crops. The amount of 

chlordane that enters the body depends on the 

amount in air, food, or water, and the length of time 

a person is exposed to it. Most chlordane that enters 

the body leaves in a few days, mostly in the feces, 

and a much smaller amount leaves in the urine. 

Chlordane and its breakdown products may be 

stored in body fat, where they cause no bad effects, 

unless released from body fat in large amounts. It 

may take months or years before the chlordane and 

the breakdown products that are stored in fat are 

able to leave the body. 

1.5 HOW CAN CHLORDANE AFFECT MY 

HEALTH? 

Most health effects in humans that may be linked to 

chlordane exposure are on the nervous system, the 

digestive system, and the liver. These effects were 

seen mostly in people who swallowed chlordane 

mixtures. Large amounts of chlordane taken by 

mouth can cause convulsions and death. 

Convulsions occurred in a man who had long-term 

skin contact with soil containing large amounts of 

chlordane. Swallowing small amounts or breathing 

air containing high concentrations of chlordane 

vapors can cause a variety of nervous system 

effects, including headaches, irritation, confusion, 

weakness, and vision problems, as well as upset 

stomach, vomiting, stomach cramps, diarrhea, and 

jaundice. 

No harmful effects on health have been confirmed 

in studies of workers who made chlordane. One 

study found minor changes in liver function in 

workers in Japan who used chlordane as a pesticide. 

There are indications that chlordane may cause 

anemia and other changes in the blood cells, but the 

evidence is not very strong. 

Animals given high levels of chlordane by mouth 

for short periods of time died or had convulsions. 

Long-term exposure of animals to chlordane in their 

food caused harmful effects in the liver. It is not 

known whether chlordane will cause cancer in 

humans after long-term exposure. Studies of 

workers who made or used chlordane do not link 

exposure with cancer, but the information is not 

sufficient to know for sure. Mice fed low levels of 

chlordane in their food for most of their lifetimes 

developed liver cancer. The International Agency 

for Research on Cancer (IARC) has determined that 

chlordane is not classifiable as to its carcinogenicity 

to humans. It is not known whether chlordane will 

cause reproductive or birth defects in humans. 

Studies of workers who made or used chlordane do 

not link exposure to the chemical with birth defects, 

but there are not enough studies in humans to know 

for sure. There is some evidence that animals 

exposed before birth or while nursing develop 

behavioral effects while growing up. 

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 

CHLORDANE 

CAS#: 12789-03-6 

Division of Toxicology May 1994 

1.6 IS THERE A MEDICAL TEST TO 

DETERMINE WHETHER I HAVE BEEN 

EXPOSED TO CHLORDANE? 

Chlordane and its breakdown products (metabolites) 

can be measured in human blood, urine, feces, and 

breast milk. Tests have shown that most Americans 

have low levels of chlordane metabolites in their 

body fat. The breakdown products can stay in body 

fat for very long periods, so finding them in body 

fat or breast milk does not tell how much or how 

long ago exposure to chlordane occurred. Not all of 

the breakdown products are specific for chlordane. 

Finding chlordane and/or breakdown products in 

your body also cannot predict what health effects 

will occur, if any. Levels in blood and fat can be 

tested, although the tests are not routinely available. 

1.7 WHAT RECOMMENDATIONS HAS THE 

FEDERAL GOVERNMENT MADE TO 

PROTECT HUMAN HEALTH? 

The EPA guidelines for drinking water suggest that 

no more than 60 ppb chlordane should be present in 

drinking water that children consume for no longer 

than 10 days. Drinking water should contain no 

more than 0.5 ppb for children or 2 ppb for adults if 

they drink the water for longer periods. 

EPA stopped all use of chlordane on food crops, 

effective March 1978. Until 1988, EPA permitted 

chlordane use for termite control or dipping the 

roots or tops of nonfood plants. On April 14, 1988, 

however, EPA stopped all sales and commercial use 

of chlordane. 

The Food and Drug Administration has established 

that the levels of chlordane and its breakdown 

products in most fruits and vegetables should not be 

greater than 300 ppb and in animal fat and fish 

should not be greater than 100 ppb. 

Federal regulations limit the amount of chlordane 

that factories can release into waste water. The EPA 

requires industry to report releases or spills of 1 

pound or more. A temporary guideline of the 

National Research Council indicated that 0.005 

mg/m3 should be the maximum amount allowed in 

the air of military housing. 

The Occupational Safety and Health Administration 

(OSHA) regulates chlordane levels in the 

workplace. The maximum allowable level in 

workplace air is 0.5 mg/m3 for a person who is 

exposed for 8 hours per workday and 40 hours per 

workweek. The National Institute for Occupational 

Health and Safety (NIOSH) also recommends an 

exposure limit of 5 mg/m3 for a person exposed to 

chlordane in the workplace for 8 hours per workday 

and 40 hours per workweek. 

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 

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 

CHLORDANE 

CAS#: 12789-03-6 

Division of Toxicology May 1994 

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). 1994 Toxicological profile for 

chlordane. 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