Health effects of 2-butoxyethanol and 2-butoxyethanol acetate

Introduction

2-Butoxyethanol (bu-tox-zi-eth-an-ol) has many names, including ethylene glycol monobutyl ether, ethylene glycol butyl ether, ethylene glycol n-butyl ether, Butyl Cellosolve, butyl glycol, butyl Oxitol, glycol butyl ether, Dowanol EB, Gafcol EB, Poly-solv EB, and Ektasolve EB. Common abbreviations for 2-butoxyethanol include BE and EGBE. It is a clear, colorless liquid that smells somewhat like ether. Most people can begin to smell 2-butoxyethanol in air at 0.10–0.40 parts of 2-butoxyethanol per million parts of air (ppm). These levels are about 500 times lower than the present standard for worker exposure. 2-Butoxyethanol has been found in air, water, and soil as a contaminant. It is completely soluble in water and in most organic solvents. This means that when 2-butoxyethanol and water or 2-butoxyethanol and organic solvents are mixed, the mixtures form one layer, unlike mixing oil and water which separate into two layers. 2-Butoxyethanol is a fire hazard when exposed to heat, sparks, or open flames.

2-Butoxyethanol in the environment comes from some industrial activities. It is usually produced by a reaction of ethylene oxide with butyl alcohol, but it may also be made by the reaction of ethylene glycol with dibutyl sulfate. 2-Butoxyethanol is widely used as a solvent in protective surface coatings such as spray lacquers, quick-dry lacquers, enamels, varnishes, and latex paints. It is also used as an ingredient in paint thinners and strippers, varnish removers, agricultural chemicals, herbicides, silicon caulks, cutting oils, and hydraulic fluids. It has other uses in metal cleaners, fabric dyes and inks, industrial and household cleaners (as a degreaser), and dry-cleaning compounds. It is also used in liquid soaps and in cosmetics.

The acetate (ass-e-tate) form of this chemical is 2-butoxyethanol acetate. It is also known as ethylene glycol monobutyl ether acetate, butoxyethyl acetate, butyl glycol acetate, ethylene glycol butyl ether acetate, acetic acid 2-butoxyethyl ester, glycol monobutyl ether acetate, Butyl Cellosolve acetate, or Ektasolve EB acetate. Common abbreviations for 2-butoxyethanol acetate include BEA and EGBEA. 2-Butoxyethanol acetate has been found in air, water, and soil as a contaminant. It is a colorless liquid with a fruity odor. Most people can begin to smell 2-butoxyethanol acetate in air at 0.10–0.48 ppm. It is only moderately soluble in water but is soluble in most organic solvents. This means that when 2-butoxyethanol acetate and water or 2-butoxyethanol and organic solvents are mixed, the mixtures form one layer, unlike mixing oil and water which separate into two layers. 2-Butoxyethanol acetate is a fire hazard when exposed to heat, sparks, flames, or oxidizers.

2-Butoxyethanol acetate in the environment also comes from some industrial activities. It is prepared by reacting 2-butoxyethanol with acetic acid, acetic acid anhydride, or acetic acid chloride. 2-Butoxyethanol acetate is widely used as a slow-evaporating solvent for lacquers, varnishes, epoxy resins, and enamels. It is also used in polyvinyl acetate latex, and it may be used in some ink and spot remover formulations.

Pathways for 2-butoxyethanol and 2-butoxyethanol acetate in the environment

2-Butoxyethanol may be released into the environment at places where it is produced or used as a solvent. Solvent-based household cleaners or building materials such as varnishes, lacquers, latex paints, and enamels may release 2-butoxyethanol into the air as they dry. Municipal landfills and hazardous waste sites can also release 2-butoxyethanol to water that is under the ground.

2-Butoxyethanol can pass into air from water and soil. In the atmosphere, 2-butoxyethanol probably exists almost entirely as a vapor. Once in the air, 2-butoxyethanol may be removed by precipitation (rain, snow, ice) or may break down to other compounds within a few days. 2-Butoxyethanol breaks down more slowly in water and soil than it does in air. It can move out of contaminated soil and move into groundwater. 2-Butoxyethanol does not build up in plants and animals.

2-Butoxyethanol acetate can pass into air from water and soil. It is directly released to the atmosphere by evaporation while it is being used as a solvent in paints, lacquers, thinners, inks, ink and spot removers, and resins. 2-Butoxyethanol acetate probably exists almost entirely as a vapor in outdoor air. It can be removed from the air by precipitation because it is moderately soluble in water. In air, 2-butoxyethanol acetate may also break down to other compounds within a few days. 2-Butoxyethanol acetate breaks down more slowly in water and soil than it does in air. It can move out of contaminated soil and move into groundwater. 2-Butoxyethanol acetate does not build up in plants and animals.

Exposure to 2-butoxyethanol and 2-butoxyethanol acetate

Many people are exposed to small amounts of 2-butoxyethanol and 2-butoxyethanol acetate every day. You can be exposed to these chemicals in the environment, in the workplace, and at home. Higher exposures usually occur in the workplace rather than in the environment or at home. The general population is exposed to 2-butoxyethanol and 2-butoxyethanol acetate mainly by breathing air or having skin contact with liquids, particularly household cleaners, that contain these compounds.

You are less likely to be exposed by eating or drinking something that contains 2-butoxyethanol. The Food and Drug Administration has regulations to control its presence as a food contaminant. However, some drinking water supplies have been shown to contain 2-butoxyethanol.

Some people have been poisoned by accidentally or intentionally drinking consumer products such as all-purpose liquid cleaners containing 2-butoxyethanol. Some people who work in silk-screening, printing, furniture production and finishing, asbestos-mastic removal, and housekeeping occupations that use materials containing 2-butoxyethanol have been exposed to this chemical. People who work in spray-painting operations, chemical production facilities, automobile repair shops, automobile manufacturing facilities, construction sites, and areas that have recently been remodeled using products that contain 2-butoxyethanol may also be exposed to this compound.

You are most likely to be exposed to 2-butoxyethanol acetate by inhaling the vapors and by skin contact with liquid and vapors. Industrial exposures are most likely through inhalation of vapors, although excessive contact with eyes and skin may also occur. 2-Butoxyethanol acetate is used as a solvent in latex paints, lacquers, epoxy resins, thinners, inks, stains, and varnishes, and in ink and spot removers. People who use these products at work or at home can be exposed by inhaling the vapors or by skin or eye contact. Exposure only occurs while these products are being used or while they are drying.

Pathways for 2-butoxyethanol and 2-butoxyethanol acetatein the body

2-Butoxyethanol and 2-butoxyethanol acetate can enter your body through your lungs when you breathe them. They can also enter your body through your stomach and intestines when you eat food or drink water that contains either one. They can enter your body through skin contact with liquid products such as paints, varnishes, ink and spot removers, and household cleaners. If your skin comes in contact with vapors of these compounds in the air, some can also enter your body through your skin. The amount of vapor that enters through your skin is much less than the amount that enters through your lungs, especially if most of your skin is covered by clothing.

When you are exposed to high levels of 2-butoxyethanol or 2-butoxyethanol acetate in air, some of the compound you breathe in leaves your body when you breathe out. The remainder passes through the lining of your lungs and enters your bloodstream. Both can also enter your bloodstream from your intestines if you swallow them. They can enter your bloodstream through your skin if your skin comes into contact with cleaning products containing them or with the vapors in the air. The amount of vapor that enters through your skin is much less than the amount that enters through your lungs, especially if most of your skin is covered by clothing. Once in your bloodstream, 2-butoxyethanol and 2-butoxyethanol acetate travel through your body to many organs and tissues, but they don't stay there very long. 2-Butoxyethanol and 2-butoxyethanol acetate are converted to products, called metabolites, in the liver. Scientists think that some of the effects of exposure to these chemicals are caused by metabolites. Most of the metabolites of 2-butoxyethanol and 2-butoxyethanol acetate leave the body in the urine within 24–48 hours after exposure. Smaller amounts of metabolites leave the body in exhaled air and in the feces.

Health effects of 2-butoxyethanol and 2-butoxyethanol acetate

You should know that 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 such health effects 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.

Additionally, there are vigorous national and international efforts to develop alternatives to animal testing. The efforts focus on both in vitro and in silico approaches and methods. For example, the National Toxicology Program (NTP) at the National Institute of Environmental Health Sciences (NIEHS) created the NTP Interagency Center for the Evaluation of Alternative Toxicological Methods (NICEATM) in 1998. The role of NICEATM is to serve the needs of high quality, credible science by facilitating development and validation—and regulatory and public acceptance—of innovative, revised test methods that reduce, refine, and replace the use of animals in testing while strengthening protection of human health, animal health and welfare, and the environment. In Europe, similar efforts at developing alternatives to animal based testing are taking place under the aegis of the European Centre for the Validation of Alternative Methods (ECVAM).

2-Butoxyethanol and 2-butoxyethanol acetate can enter your body through your lungs when you breathe them. They can also enter your body through your stomach and intestines when you eat food or drink water that contains either one. They can enter your body through skin contact with liquid products such as paints, varnishes, ink and spot removers, and household cleaners. If your skin comes in contact with vapors of these compounds in the air, some can also enter your body through your skin. The amount of vapor that enters through your skin is much less than the amount that enters through your lungs, especially if most of your skin is covered by clothing.

When you are exposed to high levels of 2-butoxyethanol or 2-butoxyethanol acetate in air, some of the compound you breathe in leaves your body when you breathe out. The remainder passes through the lining of your lungs and enters your bloodstream. Both can also enter your bloodstream from your intestines if you swallow them. They can enter your bloodstream through your skin if your skin comes into contact with cleaning products containing them or with the vapors in the air. The amount of vapor that enters through your skin is much less than the amount that enters through your lungs, especially if most of your skin is covered by clothing. Once in your bloodstream, 2-butoxyethanol and 2-butoxyethanol acetate travel through your body to many organs and tissues, but they don't stay there very long. 2-Butoxyethanol and 2-butoxyethanol acetate are converted to products, called metabolites, in the liver. Scientists think that some of the effects of exposure to these chemicals are caused by metabolites. Most of the metabolites of 2-butoxyethanol and 2-butoxyethanol acetate leave the body in the urine within 24–48 hours after exposure. Smaller amounts of metabolites leave the body in exhaled air and in the feces.

Medical tests for exposure to 2-butoxyethanol and 2-butoxyethanol acetate

Some tests can show whether you have been exposed to 2-butoxyethanol or 2-butoxyethanol acetate. 2-Butoxyethanol (from 2-butoxyethanol or 2-butoxyethanol acetate exposure) can be measured in blood and urine. In the body, both are converted to products called metabolites, such as 2-butoxyacetic acid. Certain metabolites of 2-butoxyethanol (2-butoxyacetic acid and others) can be measured in the urine. These tests will not necessarily be able to tell how much you have been exposed to. These tests need to be done within a day after exposure because 2-butoxyethanol and its metabolites leave your body within 24–48 hours. Certain blood tests can determine if your red blood cells are damaged, but this effect is not specific for 2-butoxyethanol. Some of these tests may be available at your doctor's office, or your doctor can send blood or urine samples to laboratories that specialize in performing these tests. If workers are exposed to concentrations of 5 ppm or above, the National Institute for Occupational Safety and Health recommends that the level of 2-butoxyacetic acid in the urine be measured.

Further Reading



Disclaimer: This article is taken wholly from, or contains information that was originally published by, the Agency for Toxic Substances and Disease Registry. Topic editors and authors for the Encyclopedia of Earth may have edited its content or added new information. The use of information from the Agency for Toxic Substances and Disease Registry should not be construed as support for or endorsement by that organization for any new information added by EoE personnel, or for any editing of the original content.

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Citation

(2008). Health effects of 2-butoxyethanol and 2-butoxyethanol acetate. Retrieved from http://www.eoearth.org/view/article/51cbedf77896bb431f6951a5

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