At a Glance

Phthalates are a group of chemicals used to soften and improve the flexibility and durability of plastics.

Phthalates are endocrine disruptors, and exposure to phthalates has been linked to breast cancer, developmental issues, decreased fertility, obesity and asthma.

Although some regulations ban phthalates in certain products intended specifically for young children, they are still widely used in many consumer products.

What are phthalates?

Phthalates, pronounced THAL-ates, are a group of chemicals primarily used to soften and improve the flexibility and durability of plastics. Some phthalates are also used as solvents and stabilizers in product formulations.

Where are phthalates found?

Phthalates are found in a wide variety of products, including plastics, building materials, cleaning products, insecticides, pharmaceuticals, food packaging, home décor, children’s toys, and personal care products. Some common items containing phthalates around the home:

  • Shower curtains
  • Vinyl floors
  • Mini-blinds
  • Air fresheners (plug-ins, sprays, and reed diffusers)
  • Soft-sided lunch boxes
  • Plastic food wrap and packaging[1]
  • Soft plastic food containers
  • Medical devices such as intravenous (IV) bags and tubing
  • Hair spray
  • Nail polish

Phthalates are also used in fragrances that are found in perfumes, moisturizers, shampoos and other personal care products. Because phthalates are semi-volatile, they can be found in indoor air and dust.[2] You can be exposed to phthalates by inhalation, ingestion, intravenous absorption (resulting from medical injection procedures[3]) and skin absorption.[4]

What evidence links phthalates to breast cancer?

Phthalates are endocrine disruptors and may disrupt several hormonal systems in the human body, including the estrogen and androgen systems. Evidence links several specific phthalates to breast cancer and other negative health effects.

  • A recent meta-analysis revealed that elevated urinary di(2-ethylhexyl) phthalate (DEHP) metabolite levels were associated with an increased risk for developing breast cancer. Further molecular analysis indicated that pathways involved in tumor suppression may be altered in women with higher levels of phthalates.[5]
  • Benzyl butyl phthalate (BBP) and dibutyl phthalate (DBP) have been shown to be weakly estrogenic, cause estrogen-triggered cell responses, and act in conjunction with the body’s own estrogens.[6]
  • BBP, DBP, and diisodecyl phthalate (DiBP) have been shown to bind to androgen receptors.[7]
  • BBP and DBP have been shown to cause cell proliferation, tumor formation, and malignant invasion of breast cancer cells that are low in or lack hormone receptors, indicating that there are negative health effects of phthalates beyond their direct impact on the estrogen-regulated systems.[8]
  • High levels of diethyl phthalate (DEP) have been linked to infertility in men, while high levels of DEP and DBP have been linked to infertility in women.[9]
  • Exposure to dimethyl phthalate (DMP) has been associated with early breast development, or thelarche, in girls.[10] Early breast development has been linked to an increased risk of developing breast cancer later in life.[11] Higher levels of monoethyl phthalate (MEP) were associated with earlier development of pubic hair in girls, another measure of puberty onset.[12]
  • BBP, DBP and bis(2-ethylhexyl) phthalate (DEHP) have been shown in laboratory studies to increase growth of human breast cancer cells[13] and decrease the efficacy of tamoxifen, a drug commonly used to treat breast cancer.[14]
  • DBP, BBP, and DEHP have been shown to affect the androgen system (“male” hormones) and may cause physical abnormalities in male offspring of exposed mothers, such as undescended testes, reduced distance between the anus and genitals, and other effects that would indicate a problem with normal fetal development and sex differentiation.[15],[16],[17]
  • Phthalate exposure is also associated with diabetes,[18] the onset and exacerbation of asthma,[19],[20] and possibly obesity.[[21]

What about effects of exposures to phthalates in women who have been diagnosed with breast cancer?

 In a study following women diagnosed with breast cancer as part of the Long Island Breast Cancer Study Project, urine samples were collected within 3 months of diagnosis and several phthalate metabolites were measured.  The women were then followed for a median of 17.6 years.

Levels of metabolites of DEHP, a phthalate that acts as an anti-androgen, were associated with breast cancer specific mortality in a manner that was moderated by body weight (body mass index or BMI).  For women with BMI scores in the normal or lower weight ranges, higher DEHP metabolite levels were associate with higher mortality rates.  On the other hand, for women in the higher (over weight and obese) BMI ranges, there was an inverse relationship between the metabolite levels and breast cancer specific mortality rates.[22]

Who is most likely to be exposed to phthalates?

Historically, women have had slightly higher exposures to phthalates than men; however, because phthalates have become ubiquitous in our environment, used now in everything from personal care products to industrial adhesives and building materials, everyone is equally at risk for exposure. Data collected from a nationally representative population show which subgroups of the population are most likely to be exposed to which phthalates[23]:

  • Exposure to BBP, DBP, DEHP and DMP is highest in children ages 6 to 11.
  • Exposure to DEP, used as a solvent in many products containing fragrance (e.g., perfume, deodorant, soaps and shampoos) is typically highest in men and women age 20 years and older, followed closely by 12- to 19-year-olds.
  • Data also show that non-Hispanic blacks have higher levels of phthalates than do non-Hispanic whites.

Who is most vulnerable to the health effects of phthalates?

While everyone should be concerned about exposure to phthalates, some of us are more vulnerable to adverse health outcomes than others. Fetuses and infants, who are at critical stages of development, are particularly sensitive to phthalate exposure.[24],[25] Young girls exposed to high levels of phthalates are also at risk of negative health effects.[26] Because phthalates can cross the placenta and are present in and can be transmitted though breast milk,[27] it is important that women of child-bearing age, pregnant women and mothers who are breast-feeding avoid phthalate exposure.

What are the top tips to avoid exposure?

Phthalates are ubiquitous in our environment and very hard to avoid. Here are a few tips to help you reduce your exposure:

  • Become a label reader: Avoid buying personal care products that contain “fragrance” or “perfume.” Choose nail polish that is phthalate free and bring your own polish to the nail salon if they don’t offer a phthalate-free option. These are typically labeled “DBP-free” or “Toxic Trio Free.”
  • Avoid plastics for food prep and storage: Food containers made from PVC plastics (i.e., number 3 plastics) contain phthalates, as do vinyl plastic cooking utensils, plastic food storage containers and plastic food packaging.[28],[29]
  • Use glass, ceramic or metal for storage and preparation of hot foods. Avoid hot foods packaged in plastic. Microwave in glass or ceramic, never in plastic.
  • Choose natural materials for your home. Avoid vinyl shower curtains, vinyl flooring, plastic window treatments, and vinyl replacement windows.
  • Avoid fragrances and air fresheners. FDA regulations do not require companies to list fragrance components on ingredient labels, because fragrance formulations are considered proprietary. Phthalates (especially DEP) are often added to fragrance to make the scent linger. As a result, fragrances, perfumes and scented lotions, soaps and other products can contain phthalates. Limit your use of perfumes. Avoid using artificial air fresheners such as plug-ins, sprays or artificially scented candles. Look for naturally scented candles to freshen your home, or cut some fresh flowers, or simply open a window.


Updated 2019

[1] Cirillo, Teresa et al. “Children’s exposure to Di(2-ethylhexyl)phthalate and dibutylphthalate plasticizers from school meals.” Journal of Agricultural and Food Chemistry 59, 19 (2011): 10532-8. doi:10.1021/jf2020446.

[2] Rudel, R A et al. “Identification of selected hormonally active agents and animal mammary carcinogens in commercial and residential air and dust samples.” Journal of the Air & Waste Management Association 51, 4 (2001): 499-513. doi:10.1080/10473289.2001.10464292.

[3] Schettler, Ted. “Human exposure to phthalates via consumer products.” International Journal of Andrology 29, 1 (2006): 134-9. doi:10.1111/j.1365-2605.2005.00567.x.

[4] Janjua, Nadeem Rezaq et al. “Urinary excretion of phthalates and paraben after repeated whole-body topical application in humans.” International Journal of Andrology 31, 2 (2008): 118-30. doi:10.1111/j.1365-2605.2007.00841.x.

[5] Fu, Zhiqin et al. “Association between urinary phthalate metabolites and risk of breast cancer and uterine leiomyoma.” Reproductive Toxicology 74 (2017): 134-142. doi:10.1016/j.reprotox.2017.09.009.

[6] Kang, Se Chan, and Byung Mu Lee. “DNA methylation of estrogen receptor alpha gene by phthalates.” Journal of Toxicology and Environmental Health 68, 23-24 (2005): 1995-2003. doi:10.1080/15287390491008913.

[7] Fang, Hong et al. “Study of 202 natural, synthetic, and environmental chemicals for binding to the androgen receptor.” Chemical Research in Toxicology 16, 10 (2003): 1338-58. doi:10.1021/tx030011g.

[8] Hsieh, Tsung-Hua et al. “Phthalates induce proliferation and invasiveness of estrogen receptor-negative breast cancer through the AhR/HDAC6/c-Myc signaling pathway.” FASEB Journal 26, 2 (2012): 778-87. doi:10.1096/fj.11-191742.

[9] Tranfo, Giovanna et al. “Urinary phthalate monoesters concentration in couples with infertility problems.” Toxicology Letters 213, 1 (2012): 15-20. doi:10.1016/j.toxlet.2011.11.033.

[10] Chou, Yen-Yin et al. “Phthalate exposure in girls during early puberty.” Journal of Pediatric Endocrinology & Metabolism 22, 1 (2009): 69-77. doi:10.1515/jpem.2009.22.1.69.

[11] Steingraber, Sandra. “The Falling Age of Puberty in U.S. Girls: What We Know, What we Need to Know.” San Francisco: Breast Cancer Fund, 2007.

[12] Harley, Kim G et al. “Association of phthalates, parabens and phenols found in personal care products with pubertal timing in girls and boys.” Human Reproduction 34, 1 (2019): 109-117. doi:10.1093/humrep/dey337.

[13] Kim, In Young et al. “Phthalates inhibit tamoxifen-induced apoptosis in MCF-7 human breast cancer cells.” Journal of Toxicology and Environmental Health 67, 23-24 (2004): 2025-35. doi:10.1080/15287390490514750.

[14] Gwinn, Maureen R et al. “Gene expression profiling of di-n-butyl phthalate in normal human mammary epithelial cells.” Journal of Environmental Pathology, Toxicology and Oncology 26, 1 (2007): 51-61. doi:10.1615/jenvironpatholtoxicoloncol.v26.i1.60.

[15] Foster, Paul M D. “Disruption of reproductive development in male rat offspring following in utero exposure to phthalate esters.” International Journal of Andrology 29, 1 (2006): 140-7. doi:10.1111/j.1365-2605.2005.00563.x.

[16] Latini, Giuseppe et al. “Phthalate exposure and male infertility.” Toxicology 226,2-3 (2006): 90-8. doi:10.1016/j.tox.2006.07.011.

[17] Swan, Shanna H et al. “Decrease in anogenital distance among male infants with prenatal phthalate exposure.” Environmental Health Perspectives 113, 8 (2005): 1056-61. doi:10.1289/ehp.8100.

[18] Lind, P Monica et al. “Circulating levels of phthalate metabolites are associated with prevalent diabetes in the elderly.” Diabetes Care 35, 7 (2012): 1519-24. doi:10.2337/dc11-2396.

[19] Bornehag, C G, and E Nanberg. “Phthalate exposure and asthma in children.” International Journal of Andrology 33, 2 (2010): 333-45. doi:10.1111/j.1365-2605.2009.01023.x.

[20] Bornehag, Carl-Gustaf et al. “The association between asthma and allergic symptoms in children and phthalates in house dust: a nested case-control study.” Environmental Health Perspectives 112, 14 (2004): 1393-7. doi:10.1289/ehp.7187.

[21] Kim, Shin Hye, and Mi Jung Park. “Phthalate exposure and childhood obesity.” Annals of Pediatric Endocrinology & Metabolism 19, 2 (2014): 69-75. doi:10.6065/apem.2014.19.2.69.

[22] Parada, Humberto Jr et al. “Urinary Phthalate Metabolite Concentrations and Breast Cancer Incidence and Survival following Breast Cancer: The Long Island Breast Cancer Study Project.” Environmental Health Perspectives 126, 4 047013. 26 Apr. 2018, doi:10.1289/EHP2083.

[23] Center for Disease Control and Prevention. “Fourth National Report on Human Exposure to Environmental Chemicals.” Atlanta: Center for Disease Control and Prevention, 2005.

[24] Wittassek, Matthias et al. “Fetal exposure to phthalates–a pilot study.” International Journal of Hygiene and Environmental Health 212, 5 (2009): 492-8. doi:10.1016/j.ijheh.2009.04.001.

[25] Swan, Shanna H et al. “Decrease in anogenital distance among male infants with prenatal phthalate exposure.” Environmental Health Perspectives 113, 8 (2005): 1056-61. doi:10.1289/ehp.8100.

[26] Chou, Yen-Yin et al. “Phthalate exposure in girls during early puberty.” Journal of Pediatric Endocrinology & Metabolism 22, 1 (2009): 69-77. doi:10.1515/jpem.2009.22.1.69.

[27] Hines, Erin P et al. “Concentrations of phthalate metabolites in milk, urine, saliva, and Serum of lactating North Carolina women.” Environmental Health Perspectives 117, 1 (2009): 86-92. doi:10.1289/ehp.11610.

[28] Rudel, Ruthann A et al. “Food packaging and bisphenol A and bis(2-ethyhexyl) phthalate exposure: findings from a dietary intervention.” Environmental Health Perspectives 119, 7 (2011): 914-20. doi:10.1289/ehp.1003170.

[29] Ji, Kyunghee et al. “Influence of a five-day vegetarian diet on urinary levels of antibiotics and phthalate metabolites: a pilot study with “Temple Stay” participants.” Environmental Research 110, 4 (2010): 375-82. doi:10.1016/j.envres.2010.02.008.

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