Bis(2-ethylhexyl) phthalate
Encyclopedia
Bisphthalate, commonly abbreviated DEHP, is an organic compound
with the formula
C6H4(C8H17COO)2. It is sometimes called dioctyl phthalate and abbreviated DOP. It is the most important "phthalate," being the diester
of phthalic acid
and the branched-chain 2-ethylhexanol
. This colourless viscous liquid is soluble in oil, but not in water. It possesses good plasticizing properties. Being produced on a massive scale by many companies, it has acquired many names and acronyms, including BEHP and di-2-ethyl hexyl phthalate.
with 2-ethylhexanol
:
Approximately three billion kilograms are produced annually.
in manufacturing of articles made of PVC
. Plastics may contain 1% to 40% of DEHP. It is also used as a hydraulic fluid
and as a dielectric
fluid in capacitor
s. DEHP also finds use as a solvent
in glowsticks.
). It can be absorbed from food and water. Higher levels have been found in milk and cheese. It can also leach into a liquid that comes in contact with the plastic; it extracts faster into nonpolar solvent
s (e.g. oil
s and fat
s in foods packed in PVC). Food and Drug Administration
(FDA) therefore permits use of DEHP-containing packaging only for foods that primarily contain water. In soil, DEHP contamination moves very slowly because of its low solubility in water. Therefore, leaching from disposed plastics in landfill
s is generally slow. The US EPA
limits for DEHP in drinking water
is 6 ppb
. The U.S. agency OSHA
's limit for occupational exposure is 5 mg/m3 of air.
s such as intravenous tubing and bags, catheters, nasogastric tubes, dialysis bags and tubing, and blood bags and transfusion tubing, and air tubes. For this reason, concern has been expressed about leachates transported into the patient, especially for those requiring extensive infusions, e.g. newborns in intensive care nursery
settings, hemophiliacs, and kidney dialysis patients. According to the European Commission Scientific Committee on Health and Environmental Risks
(SCHER), exposure to DEHP may exceed the tolerable daily intake in some specific population groups, namely people exposed through medical procedures such as kidney dialysis. The American Academy of Pediatrics
has advocated not to use medical devices that can leach DEHP into patients and, instead, to resort to DEHP-free alternatives. In July 2002, the U.S. FDA issued a Public Health Notification on DEHP, stating in part, "We recommend considering such alternatives when these high-risk procedures are to be performed on male neonates, pregnant women who are carrying male fetuses, and peripubertal males" noting that the alternatives were to look for non-DEHP exposure solutions; they mention a database of alternatives. The CBC
documentary The Disappearing Male raised concerns about sexual development in male fetal development, miscarriage (as DEHP is an androgen antagonist (not a pseudo-estrogen) found in polyvinyl chloride (PVC) plastic products, many cosmetics and fragrances, and numerous other consumer products), and as a cause of dramatically lower sperm counts in men.
salts. The released alcohol is susceptible to oxidation to the aldehyde
and carboxylic acid.
, and the incomplete descent of testes of their newborn sons, replicating effects identified in animals. Approximately 25% of US women have phthalate levels similar to those in the study.
data, published in Environmental Health Perspectives (EHP), "revealed that American men with abdominal obesity
or insulin resistance
(a precursor to diabetes) were more likely to have high levels of [DEHP and DBP
] metabolites in their urine than men without those problems."
. Some countries have banned DEHP from toys; see phthalate for legal status.
. This is observed in conjunction with a significant decrease in the amount of gap junction
al connexin
proteins in cardiomyocytes treated with DEHP.
, and non-phthalates, e.g. DINCH
and Citrates.
In May 2011, the illegal use of the plasticizer DEHP in clouding agent
s for use in food and beverages has been reported in Taiwan
. An inspection of products initially discovered the presence of plasticizers. As more products were tested, inspectors found more manufacturers using DEHP and DINP. The Department of Health
confirmed that contaminated food and beverages had been exported to other countries and regions, which reveals the widespread prevalence of toxic plasticizers.
Organic compound
An organic compound is any member of a large class of gaseous, liquid, or solid chemical compounds whose molecules contain carbon. For historical reasons discussed below, a few types of carbon-containing compounds such as carbides, carbonates, simple oxides of carbon, and cyanides, as well as the...
with the formula
Chemical formula
A chemical formula or molecular formula is a way of expressing information about the atoms that constitute a particular chemical compound....
C6H4(C8H17COO)2. It is sometimes called dioctyl phthalate and abbreviated DOP. It is the most important "phthalate," being the diester
Ester
Esters are chemical compounds derived by reacting an oxoacid with a hydroxyl compound such as an alcohol or phenol. Esters are usually derived from an inorganic acid or organic acid in which at least one -OH group is replaced by an -O-alkyl group, and most commonly from carboxylic acids and...
of phthalic acid
Phthalic acid
Phthalic acid is an aromatic dicarboxylic acid, with formula C6H42. It is an isomer of isophthalic acid and terephthalic acid. Although phthalic acid is of modest commercial importance, the closely related derivative phthalic anhydride is a commodity chemical produced on a large...
and the branched-chain 2-ethylhexanol
2-Ethylhexanol
2-Ethylhexanol is a fatty alcohol, an organic compound is a branched, eight-carbon chiral alcohol. It is a colorless liquid that is nearly insoluble in water but soluble in most organic solvents...
. This colourless viscous liquid is soluble in oil, but not in water. It possesses good plasticizing properties. Being produced on a massive scale by many companies, it has acquired many names and acronyms, including BEHP and di-2-ethyl hexyl phthalate.
Production
The process entails the reaction of phthalic anhydridePhthalic anhydride
Phthalic anhydride is the organic compound with the formula C6H42O. It is the anhydride of phthalic acid. This colourless solid is an important industrial chemical, especially for the large-scale production of plasticizers for plastics. In 2002, approximately 4.6 billion kilograms were...
with 2-ethylhexanol
2-Ethylhexanol
2-Ethylhexanol is a fatty alcohol, an organic compound is a branched, eight-carbon chiral alcohol. It is a colorless liquid that is nearly insoluble in water but soluble in most organic solvents...
:
- C6H4(CO)2O + 2 C8H17OH → C6H4(CO2 C8H17)2 + H2O
Approximately three billion kilograms are produced annually.
Use
Due to its suitable properties and the low cost, DEHP is widely used as a plasticizerPlasticizer
Plasticizers or dispersants are additives that increase the plasticity or fluidity of the material to which they are added; these include plastics, cement, concrete, wallboard, and clay. Although the same compounds are often used for both plastics and concretes the desired effects and results are...
in manufacturing of articles made of PVC
Polyvinyl chloride
Polyvinyl chloride, commonly abbreviated PVC, is a thermoplastic polymer. It is a vinyl polymer constructed of repeating vinyl groups having one hydrogen replaced by chloride. Polyvinyl chloride is the third most widely produced plastic, after polyethylene and polypropylene. PVC is widely used in...
. Plastics may contain 1% to 40% of DEHP. It is also used as a hydraulic fluid
Hydraulic fluid
Hydraulic fluids, also called hydraulic liquids, are the medium by which power is transferred in hydraulic machinery. Common hydraulic fluids are based on mineral oil or water...
and as a dielectric
Dielectric
A dielectric is an electrical insulator that can be polarized by an applied electric field. When a dielectric is placed in an electric field, electric charges do not flow through the material, as in a conductor, but only slightly shift from their average equilibrium positions causing dielectric...
fluid in capacitor
Capacitor
A capacitor is a passive two-terminal electrical component used to store energy in an electric field. The forms of practical capacitors vary widely, but all contain at least two electrical conductors separated by a dielectric ; for example, one common construction consists of metal foils separated...
s. DEHP also finds use as a solvent
Solvent
A solvent is a liquid, solid, or gas that dissolves another solid, liquid, or gaseous solute, resulting in a solution that is soluble in a certain volume of solvent at a specified temperature...
in glowsticks.
Environmental exposure
DEHP has a low vapor pressure, but the temperatures for processing PVC articles are often high, leading to release of elevated levels, raising concerns about health risks (see outgassingOutgassing
Outgassing is the release of a gas that was dissolved, trapped, frozen or absorbed in some material. As an example, research has shown how the concentration of carbon dioxide in the Earth's atmosphere has sometimes been linked to ocean outgassing...
). It can be absorbed from food and water. Higher levels have been found in milk and cheese. It can also leach into a liquid that comes in contact with the plastic; it extracts faster into nonpolar solvent
Solvent
A solvent is a liquid, solid, or gas that dissolves another solid, liquid, or gaseous solute, resulting in a solution that is soluble in a certain volume of solvent at a specified temperature...
s (e.g. oil
Oil
An oil is any substance that is liquid at ambient temperatures and does not mix with water but may mix with other oils and organic solvents. This general definition includes vegetable oils, volatile essential oils, petrochemical oils, and synthetic oils....
s and fat
Fat
Fats consist of a wide group of compounds that are generally soluble in organic solvents and generally insoluble in water. Chemically, fats are triglycerides, triesters of glycerol and any of several fatty acids. Fats may be either solid or liquid at room temperature, depending on their structure...
s in foods packed in PVC). Food and Drug Administration
Food and Drug Administration
The Food and Drug Administration is an agency of the United States Department of Health and Human Services, one of the United States federal executive departments...
(FDA) therefore permits use of DEHP-containing packaging only for foods that primarily contain water. In soil, DEHP contamination moves very slowly because of its low solubility in water. Therefore, leaching from disposed plastics in landfill
Landfill
A landfill site , is a site for the disposal of waste materials by burial and is the oldest form of waste treatment...
s is generally slow. The US EPA
United States Environmental Protection Agency
The U.S. Environmental Protection Agency is an agency of the federal government of the United States charged with protecting human health and the environment, by writing and enforcing regulations based on laws passed by Congress...
limits for DEHP in drinking water
Drinking water
Drinking water or potable water is water pure enough to be consumed or used with low risk of immediate or long term harm. In most developed countries, the water supplied to households, commerce and industry is all of drinking water standard, even though only a very small proportion is actually...
is 6 ppb
PPB
PPB can stand for:* Party political broadcast, a type of political programming in the United Kingdom* parts-per-billion, a unit of concentration* Portland Police Bureau, a police agency for the city of Portland...
. The U.S. agency OSHA
Occupational Safety and Health Administration
The United States Occupational Safety and Health Administration is an agency of the United States Department of Labor. It was created by Congress of the United States under the Occupational Safety and Health Act, signed by President Richard M. Nixon, on December 29, 1970...
's limit for occupational exposure is 5 mg/m3 of air.
Use in medical devices
DEHP has been used as a plasticiser in medical deviceMedical device
A medical device is a product which is used for medical purposes in patients, in diagnosis, therapy or surgery . Whereas medicinal products achieve their principal action by pharmacological, metabolic or immunological means. Medical devices act by other means like physical, mechanical, thermal,...
s such as intravenous tubing and bags, catheters, nasogastric tubes, dialysis bags and tubing, and blood bags and transfusion tubing, and air tubes. For this reason, concern has been expressed about leachates transported into the patient, especially for those requiring extensive infusions, e.g. newborns in intensive care nursery
Neonatal intensive care unit
A Neonatal Intensive Care Unit —also called a Special Care Nursery, newborn intensive care unit, intensive care nursery , and special care baby unit —is an intensive care unit specializing in the care of ill or premature newborn infants.The problem of premature and congenitally ill infants is not a...
settings, hemophiliacs, and kidney dialysis patients. According to the European Commission Scientific Committee on Health and Environmental Risks
Scientific Committee on Health and Environmental Risks
The Scientific Committee on Health and Environmental Risks is one of the independent scientific committees managed by the Directorate-General for Health and Consumer Protection of the European Commission, which provide scientific advice to the Commission on issues related to consumer products.-...
(SCHER), exposure to DEHP may exceed the tolerable daily intake in some specific population groups, namely people exposed through medical procedures such as kidney dialysis. The American Academy of Pediatrics
American Academy of Pediatrics
The American Academy of Pediatrics is the major professional association of pediatricians in the United States. The AAP was founded in 1930 by 35 pediatricians to address pediatric healthcare standards. It currently has 60,000 members in primary care and sub-specialist areas...
has advocated not to use medical devices that can leach DEHP into patients and, instead, to resort to DEHP-free alternatives. In July 2002, the U.S. FDA issued a Public Health Notification on DEHP, stating in part, "We recommend considering such alternatives when these high-risk procedures are to be performed on male neonates, pregnant women who are carrying male fetuses, and peripubertal males" noting that the alternatives were to look for non-DEHP exposure solutions; they mention a database of alternatives. The CBC
Canadian Broadcasting Corporation
The Canadian Broadcasting Corporation, commonly known as CBC and officially as CBC/Radio-Canada, is a Canadian crown corporation that serves as the national public radio and television broadcaster...
documentary The Disappearing Male raised concerns about sexual development in male fetal development, miscarriage (as DEHP is an androgen antagonist (not a pseudo-estrogen) found in polyvinyl chloride (PVC) plastic products, many cosmetics and fragrances, and numerous other consumer products), and as a cause of dramatically lower sperm counts in men.
Metabolism
DEHP hydrolyzes to MEHP (mono-ethylhexyl phthalate) and subsequently to phthalatePhthalic acid
Phthalic acid is an aromatic dicarboxylic acid, with formula C6H42. It is an isomer of isophthalic acid and terephthalic acid. Although phthalic acid is of modest commercial importance, the closely related derivative phthalic anhydride is a commodity chemical produced on a large...
salts. The released alcohol is susceptible to oxidation to the aldehyde
Aldehyde
An aldehyde is an organic compound containing a formyl group. This functional group, with the structure R-CHO, consists of a carbonyl center bonded to hydrogen and an R group....
and carboxylic acid.
Smaller penis size and other feminizing links
DEHP metabolites measured from the blood of pregnant women have been significantly associated with the decreased penis width, shorter anogenital distanceAnogenital distance
Anogenital distance is the distance from the anus to the genitalia, the base of the penis or vagina. It is considered medically significant for a number of reasons, in both humans and animals. It is regulated by dihydrotestosterone, which can be disrupted by phthalates common in plastics...
, and the incomplete descent of testes of their newborn sons, replicating effects identified in animals. Approximately 25% of US women have phthalate levels similar to those in the study.
Obesity
A study on CDCCenters for Disease Control and Prevention
The Centers for Disease Control and Prevention are a United States federal agency under the Department of Health and Human Services headquartered in Druid Hills, unincorporated DeKalb County, Georgia, in Greater Atlanta...
data, published in Environmental Health Perspectives (EHP), "revealed that American men with abdominal obesity
Obesity
Obesity is a medical condition in which excess body fat has accumulated to the extent that it may have an adverse effect on health, leading to reduced life expectancy and/or increased health problems...
or insulin resistance
Insulin resistance
Insulin resistance is a physiological condition where the natural hormone insulin becomes less effective at lowering blood sugars. The resulting increase in blood glucose may raise levels outside the normal range and cause adverse health effects, depending on dietary conditions. Certain cell types...
(a precursor to diabetes) were more likely to have high levels of [DEHP and DBP
Dibutyl phthalate
Dibutyl phthalate is a commonly used plasticizer. It is also used as an additive to adhesives or printing inks. It is soluble in various organic solvents, e.g. in alcohol, ether and benzene...
] metabolites in their urine than men without those problems."
Toxicity
The acute toxicity of DEHP is 30g/kg in rats (oral) and 24g/kg in rabbits (dermal). Concerns instead focus on its potential as an endocrine disruptorEndocrine disruptor
Endocrine disruptors are chemicals that interfere with endocrine in animals, including humans. These disruptions can cause cancerous tumors, birth defects, and other developmental disorders...
. Some countries have banned DEHP from toys; see phthalate for legal status.
Cardiotoxicity
A clinically relevant dose and duration of exposure to DEHP has been shown to have a significant impact on the behavior of cardiac cells in culture. This includes an uncoupling effect that leads to irregular rhythms in vitroIn vitro
In vitro refers to studies in experimental biology that are conducted using components of an organism that have been isolated from their usual biological context in order to permit a more detailed or more convenient analysis than can be done with whole organisms. Colloquially, these experiments...
. This is observed in conjunction with a significant decrease in the amount of gap junction
Gap junction
A gap junction or nexus is a specialized intercellular connection between a multitude of animal cell-types. It directly connects the cytoplasm of two cells, which allows various molecules and ions to pass freely between cells....
al connexin
Connexin
Connexins, or gap junction proteins, are a family of structurally-related transmembrane proteins that assemble to form vertebrate gap junctions . Each gap junction is composed of two hemichannels, or connexons, which are themselves each constructed out of six connexin molecules...
proteins in cardiomyocytes treated with DEHP.
Alternative plasticizers
Manufacturers of flexible PVC articles can choose among several alternative plasticizers offering similar technical properties as DEHP. These alternatives include other phthalates such as DINP, DPHP, DIDPDiisodecyl phthalate
Diisodecyl phthalate is a commonly used plasticizer used in the production of plastic and plastic coating to increase flexibility...
, and non-phthalates, e.g. DINCH
DINCH
1,2-Cyclohexane dicarboxylic acid diisononyl ester is a plasticizer for the manufacture of flexible plastic articles in sensitive application areas such as toys, medical devices and food packaging...
and Citrates.
Taiwan
In October 2009, Consumers' Foundation, Chinese Taipei (CFCT) published test results that found 5 out of the sampled 12 shoes contained over 0.1% of phthalate plasticizer content, including DEHP, which exceeds the government's Toy Safety Standard (CNS 4797). CFCT recommend that users should first wear socks to avoid direct skin contact.In May 2011, the illegal use of the plasticizer DEHP in clouding agent
Clouding agent
Clouding agents are a type of food additive used to make beverages such as fruit juices more cloudy, and thus more natural-looking and visually appealing, typically by creating an emulsion of oil droplets....
s for use in food and beverages has been reported in Taiwan
Taiwan
Taiwan , also known, especially in the past, as Formosa , is the largest island of the same-named island group of East Asia in the western Pacific Ocean and located off the southeastern coast of mainland China. The island forms over 99% of the current territory of the Republic of China following...
. An inspection of products initially discovered the presence of plasticizers. As more products were tested, inspectors found more manufacturers using DEHP and DINP. The Department of Health
Department of Health (Republic of China)
Department of Health of the Republic of China is an executive agency of the Executive Yuan responsible for the administration of the public health system, affordable and universal health care, hospitals, pharmaceutical, immunisation programmes, disease prevention, supervision and coordination of...
confirmed that contaminated food and beverages had been exported to other countries and regions, which reveals the widespread prevalence of toxic plasticizers.
External links
- FDA Public Health Notification: PVC devices containing the plasticizer DEHP
- ATSDR ToxFAQs
- National Pollutant Inventory - Bis 2 ethylhexyl phthalate fact sheet
- Eco-USA
- DEHP Information Centre (pro-DEHP, industry-backed group)
- Report on DEHP by noharm.org
- Industry report
- Detailed overview of medical DEPH effects and strategies to avoid it (German)
- Spectrum Laboratories Fact Sheet
- ChemSub Online : Bis(2-ethylhexyl) phthalate -DEHP.