The chapter I'm reading is talking about phthalates in cosmetics. They are what is considered to be a plasticizers; meaning basically that they help to keep things from being brittle. They are have been found in things like nail polish and hair spray. After reading the chapter I went online to do a little recent research. I found this interesting from the environmental working group:
DBP as a plasticizer in nail enamelThe plasticizing and film-formation properties of DBP make the chemical particularly useful for nail polish. After nail polish is applied, some of the ingredients volatilize and leave behind a film that is the coating over the nail. DBP is one of the ingredients left behind, reducing brittleness and cracking in the polish.
If the DBP stayed intact in the polish, women might absorb negligible amounts of the chemical into their bodies. But a group of scientists in Hamburg, Germany showed that water-soluble components of the polish, like DBP, are dissolved out of the polish each time they contact water, a conclusion they reached after measuring the leaching of DBP from nail polish that had dried for three days. In fact, one of the reasons nail polish eventually chips is that it becomes brittle as DBP is leached out of the film. This means that every time a woman washes her hands, DBP is washed out of her nail polish and contacts her skin. The scientists conclude that "water-soluble components... attain the skin during extensive but transient contact." Therefore, a woman wearing nail polish not only can absorb DBP through her nail, but also has multiple opportunities to absorb DBP directly through her skin.
The book I'm reading has phthalates seeming way more harmful, which is why I suppose that all of this info needs to be taken with a grain of salt...and also why it's important to wash your hands. :)