Biomonitoring - Phthalates
Phthalates are chemicals commonly used to increase the flexibility of plastics in a wide array of consumer products. The main way people are exposed to phthalates is through food, especially from packaging or processing. Some phthalates are suspected endocrine disruptors which means they may interfere with the body’s natural hormones, even at low levels of exposure. Scientists are concerned about the potential for endocrine disruptors to adversely affect children’s health including their development and behavior.
Indicators
B8: Phthalate metabolites in women
Web update: 2023
Key Information
- Women’s exposure to these common phthalates has decreased over time. For example, in 2017-2018, the median level of DEHP metabolites in urine of women of child-bearing age was 9 µg/L , a decrease from 51 µg/L in 2007-2008. The median represents the midpoint of exposure. Metabolites are substances made when the body breaks down chemicals.
- Between 1999-2000 and 2017-2018, the median level of DBP metabolites in women’s urine decreased from 33 µg/L to 21 µg/L.
- In 2015-2018, Black non-Hispanic women had higher median concentrations of all the phthalate metabolites than any other group.
- For the years 2015-2018, women living below poverty level had higher levels of phthalate metabolites in their urine compared with women living at or above poverty level.
Data Characterization
Data for this indicator are obtained from an ongoing continuous survey conducted by the National Center for Health Statistics.
Survey data are representative of the U.S. civilian noninstitutionalized population.
Phthalate metabolites are measured in urine samples obtained from individual survey participants.
B9: Phthalate metabolites in children
Web update: 2023
Key Information
- Children’s exposure to these common phthalates has decreased over time. For example, in 2017-2018, the median level of DEHP metabolites in children’s urine was 13 µg/L, a decrease from 57 µg/L in 2001-2002. The median represents the midpoint of exposure. Metabolites are substances made when the body breaks down chemicals.
- The median level of BBzP metabolite in children’s urine decreased from 25 µg/L in 1999-2000 to 5 µg/L in 2017-2018.
- In 2015-2018, Black children had higher median levels of all three phthalate metabolites in their urine than all other groups.
- In 2015-2018, children living below the poverty level had higher median levels of all three phthalate metabolites in their urine compared with children living at or above the poverty level.
Data Characterization
Data for this indicator are obtained from an ongoing continuous survey conducted by the Centers for Disease Control and Prevention’s National Center for Health Statistics.
Survey data are representative of the U.S. civilian non-institutionalized population.
Phthalate metabolites are measured in urine samples obtained from individual survey participants.
About the Phthalates Indicators
Phthalates are a class of manufactured chemicals commonly used to increase the flexibility of plastics in a wide array of consumer products. By far the most common use of phthalates is in the production of polyvinyl chloride (PVC) products—PVC is the second most commonly used plastic in the world, and is present in pipes and tubing, construction materials, packaging, electrical wiring, and thousands of consumer goods. Phthalates may be found in wall coverings, tablecloths, floor tiles, furniture upholstery, pesticides, some toys, automobile upholstery, food packaging, cosmetics, hair and skin care products, and some medications.
Phthalates are not strongly bound to the materials they are used in, so they can leach out. The main way people are exposed to phthalates is through food, especially from packaging or processing. People can also be exposed through contaminated air and drinking water, and through contact with plastic materials, including touching and chewing on objects, a behavior common in young children.
Some phthalates are suspected endocrine disruptors which means they may interfere with the body’s natural hormones, even at low levels of exposure. Hormones help control many important functions in the body, like growth, development and reproduction. Because of this, scientists are concerned about the potential for endocrine disruptors to adversely affect children’s health including their development and behavior. The National Research Council has concluded that prenatal exposure to certain phthalates causes problems in the reproductive system of male rats, and similar effects could happen in people. EPA is currently evaluating seven phthalates under the Toxic Substances Control Act (TSCA), including how being exposed to several phthalates at once could affect people’s health.
For historic and contextual information about phthalates and these indicators, see the Phthalates section of America's Children and the Environment, Third Edition (pdf) .
Data Sources and Methods - Phthalates
The National Center for Health Statistics, a division of the Centers for Disease Control and Prevention, conducts the National Health and Nutrition Examination Surveys (NHANES), a series of U.S. national surveys of the health and nutrition status of the non-institutionalized civilian population. Interviews and physical examinations are conducted with approximately 10,000 people in each two-year survey cycle. The survey measures phthalate metabolite levels in urine samples collected from NHANES participants. Metabolites are substances made when the body breaks down chemicals. Some chemicals, including phthalates, break down quickly in the body. For these chemicals, metabolites are the best way to measure exposure. The three phthalate metabolites included in this indicator are mono-n-butyl phthalate (MBP), mono-benzyl phthalate (MBzP), and the sum of the three metabolites mono-2-ethylhexyl phthalate (MEHP), mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP), and mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP). However, this indicator does not account for the manufacturing and use of other phthalates which may also result in human exposure.
These indicators focus on both women of child-bearing age and children because of concern for potential adverse effects in children born to women who have been exposed to phthalates and in children exposed to phthalates.
- Detailed Methods for Indicators B9 and B10 (pdf)
- Metadata for National Health and Nutrition Examination Surveys (NHANES)
Related Links
- U.S. EPA: Phthalates
- National Research Council: Phthalates and Cumulative Risk Assessment
- Agency for Toxic Substances and Disease Registry (ATSDR): Phthalates
- Centers for Disease Control and Prevention (CDC): National Report on Human Exposure to Environmental Chemicals
- Consumer Product Safety Commission (CPSC): Phthalates
- U.S. Food and Drug Administration (FDA): Phthalates and Cosmetic Products