A salt made up of an acid
and a base
The acid in phthalate salts is phthalic acid
Phthalates such as the plasticiser di(2-ethylhexyl)phthalate (DEHP) are the chemicals that makes plastics like PVC bend. They are also used in conjunction with dyes to color textiles. They are used in cosmetics and shampoo. As a humectant, they act to retain humidity, in their role as an emollient they soften and soothe the skin. During some, but not all, medical procedures, especially those using PVC tubes, there can be a higher exposure to DEHP.
Phthalates are implicated in causing problems to the sperm production of males, causing infertility and maybe causing cancer by making the cells in the testicles forget their sexual inclination and purpose.
This is because phthalates resemble the female sexual hormone estrogen. The problem is exacerbated by the fact that during the pregnancy, a male foetus is usually protected from the mother's estrogen, however, it is not protected from the phthalates, causing a severe shortage of sperms, because some cells receive signals to behave like female cells, not like male cells. This is extremely bad because it happens so early and has consequences for the whole life, because whole groups of cells might fail to grow into their function as sexual organs or makers of sperms.
However, there are also other chemicals like DDT and PCB which could be a cause of these health problems. The chemical industrial complex has set up a .org web site named after phthalates which claims that everything is fine and that only lab rats have problems, not lab monkeys.
Will our society go into decline just as the roman empire, which had similar problems with lead poisioning? The Romans where not only using aqueducts to carry water, but also lead pipes. In fact, they also put lead in dyes and cosmetics.
Unlike for DDT where the threat is commonly accepted, the severity of the risk is unknown and I would be happy to update this node if it turns out to be low. Also, unfortunately I didn't turn up a structural formula for estrogen to compare the chemical structure by eye.
A review by a NIH panel in July 2000 found that DEHP gives rise to concern. The defenders of phthalates that I saw often relied on documents from 1997 or earlier.
FDA http://www.fda.gov/cdrh/safety/dehp.html provided by Doyle.
Lead info by yclept.