They are mainly used as plasticizers, which are substances added to plastics to increase their flexibility, transparency, durability, and longevity.
Phthalates are bonding or fixative solvents and are found in fragrance and a multitude of other beauty products. The most common way phthalates are displayed on an ingredients list is DBP, DEHP, and DEP. Mostly, they’re still hidden behind fragrances that are not naturally derived. Phthalates have been linked to hormonal disruption.
The EU REACH act of 2015 imposed restrictions on phthalates. In 2019, the restriction of .3% was increased to an even more stringent level of .1% [4].
[1] NIH. NCBI. Urinary Levels of Seven Phthalate Metabolites in the U.S. Population from the National Health and Nutrition Examination Survey (NHANES). Manori J. Silva, Dana B. Barr, John A. Reidy, Nicole A. Malek, Carolyn C. Hodge, Samuel P. Caudill, John W. Brock, Larry L. Needham, and Antonia M. Calafat. (2002). http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1241863/pdf/ehp0112-000331.pdf
[2] NIH, NCBI. Shanna H. Swan,1 Katharina M. Main,2 Fan Liu,3 Sara L. Stewart,3 Robin L. Kruse,3 Antonia M. Calafat,4 Catherine S. Mao,5 J. Bruce Redmon,6 Christine L. Ternand,7 Shannon Sullivan,8 J. Lynn Teague,9 and the Study for Future Families Research Team*. Male Infants with Prenatal Phthalate http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1280349/pdf/ehp0113-001056.pdf
[3] NIH, NCBI. Pant N1, Pant A, Shukla M, Mathur N, Gupta Y, Saxena D. (2015). Environmental and experimental exposure of phthalate esters. http://www.ncbi.nlm.nih.gov/pubmed/20551087
[4] European Union. ECHA. Annex XIV of REACH. (2019). https://echa.europa.eu/-/endocrine-disrupting-properties-to-be-added-for-four-phthalates-in-the-authorisation-list
[5] NIH. NCBI. Thyroid effects of endocrine disrupting chemicals. (2012). https://www.ncbi.nlm.nih.gov/pubmed/21939731