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PUBLIC HEALTH STATEMENT 

ISOPHORONE 

CAS#: 78-59-1 

Division of Toxicology December 1989 

This Public Health Statement is the summary 

chapter from the Toxicological Profile for 

Isophorone. 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. 

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1.1 WHAT IS ISOPHORONE? 

Isophorone is a clear liquid with a peppermint-like 

odor. It evaporates faster than water but slower than 

charcoal starter or paint thinner, and it will not mix 

completely with water. Isophorone is a manmade 

chemical for use commercially, but it has been 

found to occur naturally in cranberries. It is used as 

a solvent in some printing inks, paints, lacquers, and 

adhesives. Isophorone does not remain in the air 

very long, but can remain in water for possibly 

more than 20 days. The length of time that 

isophorone will remain in soil is not known, but it 

probably is about the same as the length of time it 

remains in water. 

1.2 HOW MIGHT I BE EXPOSED TO 

ISOPHORONE? 

Exposure to isophorone may take place where you 

work or in very low concentrations at home. 

Because it is used in some inks, paints, lacquers, 

and adhesives, people who work with these 

products may be exposed to isophorone. 

Isophorone has been found in the drinking water of 

Cincinnati, Philadelphia, and New Orleans at 

amounts less than 10 parts of isophorone in 1 billion 

parts of water (10 ppb). In one instance (a screen 

print shop), isophorone was found in amounts as 

high as 26 parts in 1 million parts of air (26 ppm), 

but the usual amounts in the workplace are much 

lower. At this time, isophorone has been found in at 

least 9 out of 1177 National Priorities List (NPL) 

hazardous waste sites in the United States. Exposure 

to isophorone at these sites may occur by touching 

contaminated soil, water, or sediment. 

1.3 HOW CAN ISOPHORONE ENTER AND 

LEAVE MY BODY? 

Isophorone can enter your body if you breathe its 

vapor, have skin contact with it, drink contaminated 

water, or eat contaminated food. If isophorone is 

present at a waste site near homes that use local 

wells as a source of water, the well water could be 

contaminated with isophorone. Experiments in 

animals show that after doses by mouth, isophorone 

enters easily and spreads to many organs of the 

body, but most of it leaves the body within 24 hours 

in the breath and in urine. Isophorone may enter the 

lungs of workers exposed to isophorone where it is 

used indoors as a solvent. Isophorone disappears 

quickly from outside air, so the chance of breathing 

outdoor air contaminated with isophorone is small. 

If isophorone is spilled at a waste site and 

evaporates, however, a person nearby may breathe 

isophorone before it disappears from the air. In 

addition, soil around waste sites may contain 

isophorone, and a person, such as a child playing in 

the dirt, may eat or have skin contact with the 

contaminated soil. How much isophorone enters the 

body through the skin is not known. 

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 

ISOPHORONE 

CAS#: 78-59-1 

Division of Toxicology December 1989 

1.4 HOW CAN ISOPHORONE AFFECT MY 

HEALTH? 

The only effects of isophorone reported in humans 

are irritation of the skin, eyes, nose, and throat, and 

possibly dizziness and fatigue. These effects have 

occurred in workers who breathe vapors of 

isophorone and other solvents during use in the 

printing industry. Short-term exposure of animals to 

high vapor amounts and short- or long-term 

exposure of animals to high doses by mouth cause 

death or a shortened lifespan. Short-term exposure 

to high amounts of vapors or high doses by mouth 

has caused inactivity and coma in animals. 

Inconclusive studies suggested that isophorone may 

have caused birth defects and growth retardation in 

the offspring of rats and mice that breathed the 

vapors during pregnancy. 

Some harmful health effects were seen in adult 

female animals in these studies. It is not known 

whether isophorone could cause birth defects in 

humans. In a long-term study in which rats and 

mice were given high doses of isophorone by 

mouth, the male rats developed kidney disease and 

kidney tumors. Male rats also developed tumors in a 

reproductive gland. Some male mice developed 

tumors in the liver, in connective tissue, and in 

lymph glands (tissues of the body that help fight 

disease), but the evidence was not strong. It is not 

known whether isophorone causes cancer in 

humans. 

1.5 WHAT LEVELS OF EXPOSURE HAVE 

RESULTED IN HARMFUL HEALTH 

EFFECTS? 

Odor is first notice at about 0.2 ppm. This means 

that you can probably smell isophorone before you 

would have harmful health effects. 

Eye, nose, and throat irritation have been seen in 

people at isophorone levels of 25 ppm from shortterm exposures, and fatigue and depression from 

long-term exposure have been seen at 5 ppm. 

The levels of isophorone in air that cause death and 

lung congestion in animals are much higher than the 

amounts that workers breathe in industry when 

using isophorone as a solvent. The amount that 

causes lung irritation in animals is about the same 

as the amount that causes eye, nose, and throat 

irritation in humans. Skin irritation or eye damage 

has occurred in animals after a few drops of 

isophorone was applied directly to the skin or eyes. 

1.6 IS THERE A MEDICAL TEST TO 

DETERMINE WHETHER I HAVE BEEN 

EXPOSED TO ISOPHORONE? 

No medical test is known to determine human 

exposure to isophorone. A few studies in rats and 

rabbits have shown that isophorone and its 

metabolites can be found in the urine of these 

animals, so it may be possible to find a method for 

testing the urine of humans to determine exposure 

to isophorone. It is not known, however, whether 

such a measurement would predict how much 

exposure had occurred or the possible health effects. 

1.7 WHAT RECOMMENDATIONS HAS THE 

FEDERAL GOVERNMENT MADE TO 

PROTECT HUMAN HEALTH? 

The EPA recommends that levels in lakes and 

streams should be limited to 8.4 ppb to prevent 

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 

ISOPHORONE 

CAS#: 78-59-1 

Division of Toxicology December 1989 

possible health effects from drinking water or eating 

fish contaminated with isophorone. 

The EPA requires that discharges, spills, or 

accidental releases of 5,000 pounds or more of 

isophorone must be reported to the EPA. 

The Occupational Safety and Health Administration 

(OSHA) has set a permissible exposure limit of 140 

milligrams of isophorone per cubic meter of air 

(140 mg/m3) for an 8-hour workday in a 40-hour 

workweek. 

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). 1989. Toxicological profile for 

isophorone. 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