Kingsport Times-News, J. Ann Tipton
Published October 8, 2005
It's one of the most widely used chemicals in the past half century. You probably don't know it, but you and your family come in contact with trace amounts of different forms of it every day. Now the safety of long-term exposure to phthalates - pronounced "thall-ates" - is once again in question.
Forms of the chemical can literally be found all around. Some types of nail polish, perfume, toys, cars, time-release coatings on pills, flooring, lubricants, glues and safety glass contain different amounts of the chemical derived from petroleum byproducts. And the list goes on.
Eastman Chemical Co. has been interested and involved in phthalates research for decades, Product Safety and Health Director Marc Schurger said. The chemical company manufactures four different forms of the chemical, some used to make rigid vinyls flexible - like vinyl flooring or the plastic parts of a three-ring binder - and others used as fixatives in some perfumes that help the scent linger longer.
According the the American Chemistry Council, phthalates are among the most studied chemicals and have proved safe for more than 50 years. Research has shown phthalates do not persist in the environment, the council's Web site states. Once inside the body, they break down quickly and are excreted.
But according to a recent article in the Wall Street Journal, long-term studies involving rodents exposed to phthalates have led researchers to find a possible statistical link to health concerns in male human infants.
According to the article, a small study found that baby boys whose mothers had the greatest phthalate exposures while pregnant were more likely than other baby boys to have certain demasculinized traits such as smaller genitalia, on average, and were more likely to have incompletely descended testicles. Another study found that 3-month-old boys exposed to higher levels of phthalates through breast milk produced less testosterone than baby boys exposed to lower levels of the chemicals.
The studies, however, are answering few and raising more questions for companies like Eastman.
"I'd like to know if they controlled for any other material that has been alleged to cause similar effects," Schurger said. "The bottom line is that the dose makes the poison. (The Centers for Disease Control) is finding these chemicals are only showing up in humans in the parts-per-billion."
To put that concentration into perspective, Schurger said, one part-per-billion is equal to one inch in 16,000 miles.
One popular belief chemists have been combating for years is that disposable plastic soda or water bottles contain phthalates that can leach into the bottle's contents, especially if the bottle is reused.
"The fact is that those bottles are an entirely different plastic and contain no phthalates," Schurger said. "The root word 'phthalate' is the same, but chemically they are entirely different. There are no chemicals in them that will leach out, even if the bottle is used over and over again."
Most researchers are saying it's still too early to know exactly what effect, if any, phthalates are really having on human health. Studies need to be repeated and enlarged to understand what's really going on.
"We want to be responsible; we want to participate in these studies; we want to understand any potential impact of these chemicals," Schurger said. "But we also want a fair shake in that we don't want allegations about adverse effects of our chemicals just to play out and not be really looked at in good scientific fashion."
For individuals looking to limit their exposure to phthalates, Schurger said, a little common sense goes a long way..
"People shouldn't chew on vinyl plastics," he said. "And it wouldn't be a good idea to misuse fingernail polish by painting directly onto the skin. Still, we're talking about very low concentrations of phthalates."
This isn't the first time the safety of the chemical has been questioned. Consumer groups like Environmental Working Group and Health Care Without Harm have been working to change the manufacturing practice of using phthalates, especially in cosmetics.
Citing animals studies that have linked phthalates to birth defects, including liver and kidney damage and malformation of the testes, many of the consumer groups are asking the U.S. Food and Drug Administration to regulate phthalates in consumer products, especially in cosmetics.
If the government ever decided to put a nix on phthalates, the United States would be following suit with both Japan and the European Union - governments that in recent years have banned certain types of phthalates in food-handling equipment, cosmetics and some toys.
