The Breast Cancer Prevention Partners (BCPP) summarizes the state of research concerning the relationship between phthalates, a group of chemicals primarily used to soften and improve the flexibility and durability of plastics, and 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.