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ToxFAQsTM for 4,4'-Methylenebis(2-Chloroaniline)(MBOCA)

(Metileno Bis-ortocloro anilina (MBOCA))

September 1995

CAS#: 101-14-4

ToxFAQsâ„¢ PDF PDF Version, 181 KB

This fact sheet answers the most frequently asked health questions about 4,4'-methylenebis(2-chloroaniline)(MBOCA). For more information, you may call the ATSDR Information Center at 1-800-232-4636. This fact sheet is one in a series of summaries about hazardous substances and their health effects. It is important you understand this information 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.


Exposure to 4,4'-methylenebis(2-chloroaniline) (MBOCA) happens mostly in the workplace by touching it or by breathing contaminated air. MBOCA is suspected of causing bladder cancer in people and animals. This chemical has been found in at least 4 of 1,416 National Priorities List sites identified by the Environmental Protection Agency.

What is 4,4'-methylenebis(2-chloroaniline)(MBOCA)?

MBOCA is a synthetic chemical used primarily to make polyurethane products. Pure MBOCA is a colorless, crystalline solid, but the commonly used form is usually yellow, tan, or brown pellets. It has no smell or taste.

Examples of these products include gears, gaskets, sport boots, roller skate wheels, shoe soles, rolls and belt drives in cameras, computers and copy machines, wheels and pulleys for escalators and elevators, components in home appliances, and various military applications. It is also used as a coating in chemical reactions to "set" glues, plastics, and adhesives. Because plastics have many uses, MBOCA is widely used.

Other names for MBOCA include 4,4'-methylenebis(2-chloroaniline), methylene-bis-ortho-chloro-aniline, bis-amine, DACPM, MCA, and MOCA.

What happens to 4,4'-methylenebis(2-chloroaniline)(MBOCA) when it enters the environment?

  • It enters the environment from the disposal of solid waste from manufacturing plants that use MBOCA.
  • It doesn't dissolve in water easily.
  • MBOCA sticks strongly to soil particles.
  • It is not likely to enter groundwater.
  • MBOCA is not likely to evaporate from soil or water.
  • It is broken down by sunlight in air and by microscopic organisms in soil or water.
  • Levels of MBOCA can build up in the roots of vegetables grown in contaminated soil.

How might I be exposed to 4,4'-methylenebis(2-chloroaniline)(MBOCA)?

  • People who work with MBOCA may get it on their skin and breathe it in air. Skin contact is the most common way to be exposed.
  • It is sometimes found in root crops (such as carrots and beets) that people eat if the plants were grown in soil containing MBOCA.
  • People may be exposed through skin contact with soil contaminated with MBOCA or near waste sites or landfills.
  • It is not usually found in drinking water.

How can 4,4'-methylenebis(2-chloroaniline)(MBOCA) affect my health?

There is not much information on how MBOCA can affect people's health. Studies of human exposure suggest that the small amounts of MBOCA usually found in the air or on surfaces in or near factories do not cause toxic effects. Exposure to large amounts of MBOCA may cause harm, but no such exposures have been reported. We do not know if there are any other long-term health effects in people caused by MBOCA, other than cancer.

One man was accidentally sprayed in his face with hot MBOCA. He felt nauseated and his kidneys were affected, but these effects lasted less than one day. MBOCA is harmful to blood cells and the liver in dogs and rats.

Researchers do not know if MBOCA causes birth defects in people.

How likely is 4,4'-methylenebis(2-chloroaniline)(MBOCA) to cause cancer?

The Department of Health and Human Services has determined that MBOCA may reasonably be anticipated to be a carcinogen.

MBOCA is suspected of causing bladder cancer in people. Information is being gathered to determine whether bladder cancer in people may result from short-, medium-, or long-term exposures to MBOCA. A few studies have found an above-normal number of bladder tumors in workers exposed to MBOCA for several years. It caused lung, liver, breast, and bladder cancer in rats, mice, and dogs that ate MBOCA for over a year.

Is there a medical test to show whether I've been exposed to 4,4'-methylenebis(2-chloroaniline)(MBOCA)?

Laboratory tests can measure MBOCA in urine. The test must be done within a short period after you are exposed because it is broken down quickly by your body. The test does not tell how much MBOCA you've been exposed to or if harmful effects will occur. The test is not routinely available at your doctor's office, but a sample taken in the doctor's office can be shipped to a special laboratory if necessary.

Has the federal government made recommendations to protect human health?

The Environmental Protection Agency (EPA) has classified MBOCA as a hazardous waste that must meet specific disposal requirements. The EPA requires that spills or accidental releases of MBOCA into the environment of 10 pounds or more must be reported to EPA.

The American Conference of Governmental Industrial Hygienists (ACGIH) set a maximum level of 0.11 milligrams of MBOCA per cubic meter (0.11 mg/m�) of workplace air for an 8-hour workday, 40-hour workweek.

The National Institute for Occupational Safety and Health (NIOSH) recommends an exposure limit of 3 micrograms of MBOCA per cubic meter of air (3 mg/m�) over a 10-hour day.

These agencies advise avoiding eye and skin contact because this may be a route of significant exposure.


Carcinogen: A substance that can cause cancer.

Microgram (mg): One millionth of a gram.

Milligram (mg): One thousandth of a gram.

Tumor: An abnormal mass of tissue.


Agency for Toxic Substances and Disease Registry (ATSDR). 1994. Toxicological Profile for 4,4'-methylenebis(2-chloroaniline) (MBOCA). Atlanta, GA: U.S. Department of Health and Human Services, Public Health Service.

Where can I get more information?

If you have questions or concerns, please contact your community or state health or environmental quality department or:

For more information, contact:
Agency for Toxic Substances and Disease Registry
Division of Toxicology and Human Health Sciences
1600 Clifton Road NE, Mailstop S102-1
Atlanta, GA 30333
Phone: 1-800-CDC-INFO · 888-232-6348 (TTY)
Email: Contact CDC-INFO

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.

Contact Us:
  • Agency for Toxic Substances and Disease Registry
    4770 Buford Hwy NE
    Atlanta, GA 30341
  • 800-CDC-INFO
    TTY: (888) 232-6348
  • New Hours of Operation
    8am-8pm ET/Monday-Friday
    Closed Holidays
    Contact CDC-INFO The U.S. Government's Official Web PortalDepartment of Health and Human Services
Agency for Toxic Substances and Disease Registry, 4770 Buford Hwy NE, Atlanta, GA 30341
Contact CDC: 800-232-4636 / TTY: 888-232-6348

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