Phthalates? Find out why they have been linked with sex toys and obesity!

By William Atkins
Tuesday, 27 March 2007 05:45

Science - Health

Phthalates, or phthalate esters, began to be manufactured in the 1920s, but didn’t become widely used until the 1950s. In the mid-2000s, about one billion pounds (363 million kilograms) of phthalates are made around the world. One of the most common phthalate is benzylbutylphthalate (BBzP), which is used to make foamed PVC (polyvinyl chloride).

Recently, U.S. research physician Richard W. Stahlhut, from the University of Rochester’s School of Medicine and Dentistry (New York) and fellow researchers used data collected from over 1,450 men by the U.S. Centers for Disease Control and Prevention (CDC). They found that the tested men with abdominal obesity, insulin resistance, or both, were more likely to have higher concentrations of products broken down from phthalates in their urine.

The researchers say that phthalate metabolites (those products broken down from phthalates) are found in about 75% of the U.S. population. Stahlhut’s results will soon be found online and in a future issue of Environmental Health Perspectives.

In the past, various types of phthalates have been linked with allergies in children; feminism in boys (due to increased production of the female hormone estrogen); and smaller penises in infant boys. Other studies with male animals showed a relationship with decreased testosterone concentrations and abnormal reproductive developments. However, some of these studies were criticized with respect to their experimental techniques. Other studies showed no such associations.

In the face of such controversy from past studies, Stahlhut recommends that further studies be conducted, especially with regards to consumers who are in frequent contact with phtlalates in their everyday lives versus those who are not in heavy contact.

So, what exactly are phthalates?

Phthalate esters, or phthalates, are classified as: dialkyl or alkyl aryl esters of 1,2-benzenedicarboxylic acid.

More simply, they are liquid compounds that allow molecules in hard vinyl, for instance, to easily slide against one another; thus, to become more soft and flexible. This is the basic reason why phthalates are called plasticizers: because they soften hard plastics. A hard vinyl might be a water pipe for a kitchen sink or vinyl siding on the outside of a house. However, soft vinyl could be such items as shower curtains, toys, and flooring. Flexible vinyl is a very popular plastic due to its low cost, strength, and many uses.