By Brian Reid

Phthalates, chemical substances that make plastic more flexible without reducing its strength, are an all-but-inescapable part of life in the 21st century. They're used in toys, garden hoses, shower curtains and medical devices. They're also common ingredients in beauty products, making nail polish chip-resistant and making hair spray keep a bouffant in line.

But a small coalition of consumer groups, led by Environmental Working Group and Health Care Without Harm, has cried foul, claiming the chemicals' risk to millions of cosmetic-wearing women has been underestimated. Over the past months, citing animals studies that have linked the additives (pronounced THAY-lates) to birth defects, including liver and kidney damage and malformation of the testes, the anti-phthalates groups have run ads in The Washington Post and the New York Times warning of toxic chemicals lurking in perfumes and hair mousse.

Last week the Cosmetic Ingredient Review (CIR), a scientific panel that monitors the safety of substances in U.S. cosmetics, weighed in on the matter and came away unswayed by the activists. The CIR, which claims to operate independently of the Cosmetic, Toiletry and Fragrance Association that funds it, said there's no new evidence to suggest that phthalates in cosmetics pose any health risk to women or their offspring.

"As used, phthalates are safe. The concentrations at which phthalates are used in cosmetics are low compared to the levels known to toxic in animal tests," said Alan Anderson, the director and scientific coordinator for the panel, who said the panel found the products had "a wide margin of safety."

The CIR's decision, however, is not likely to end debate on the matter. And that's not just because the environmental activists are voicing disatisfaction with the ruling. It's also because the government concedes there just isn't enough human science on the issue to disconnect rodent ills from human risk.

"The animal data definitely show an effect [injurious to health]," says Jim Pirkle, the deputy director of science for the environmental health lab at the Centers for Disease Control and Prevention, "but that effect is dependent on the dose. We're not able to say right now" what the safe human dose is, he said. "There's uncertainly in the area, so that people on one side the issue grab that for one reason and people on the other side grab it for another reason."

For the time being at least, the Food and Drug Administration (FDA), which regulates cosmetics, sees no new cause for concern over the chemicals, which have been a part of life for the better part of a century.

"We still think that phthalates are safe in cosmetics," said Monica Revelle, an agency spokeswoman. "There's no new safety information that would cause us to open up the record at the present time."

Vanity at a Price?

Cosmetics are just the latest battleground over phthalates, which have aroused safety concerns for decades. In 1984 the CIR first declared phthalates safe in cosmetics. It stuck to that position even after data were released suggesting that the chemicals affected the hormones of developing animals.

Since the mid-1990s, groups such as Greenpeace have taken up the anti-phthalate cause, raising questions about whether plastic IV bags expose patients to unreasonable risks and whether certain phthalate-containing plastic toys harm children.

The FDA has recommended that doctors performing certain procedures, such as dialysis in pregnant women and newborn boys, should look for alternatives to phthalate-containing devices, which leach the chemicals at far higher rates than cosmetics do.

The Consumer Product Safety Commission (CPSC) has deemed that toys made with the chemical are generally safe but recommended that, as a precaution, phthalates should be removed from baby rattles and teethers.

In 1998, several toy makers yielded to marketplace fears and agreed to follow the CPSC recommendation to search for phthalate replacements. In 1999 the medical product maker Baxter announced it, too, would seek phthalate alternatives. Some cosmetic makers are already following the same pattern: Last week The Body Shop, the U.K.-based beauty products retailer, said it would phase out phthalate-containing products.

A study done over the summer by an independent Chicago lab found that phthalate-containing cosmetics are the rule, not the exception, with more than 70 percent of products tested -- from Eternity perfume to Degree deodorant -- coming up positive for the chemicals. Phthalates are not listed on product labels, however -- nor is there any requirement that they be listed -- so consumers can't easily identify or avoid products that contain them. A Web site posted by the anti-phthalate activists, www.nottoopretty.org, lists several dozen U.S. beauty products said to contain the chemicals; no manufacturer responses are included.

Waiting for Answers

In the cosmetics debate, some facts are known. Studies have shown clear evidence of harm in laboratory animals given high doses of phthalates in food and liquids. And there is growing evidence that humans are exposed to the chemicals at higher rates than had been previously thought. The chemicals are circulating in the body of nearly every American, the CDC has found. Still, because widespread testing has just begun, it's not known if the concentration is on the rise -- or anywhere remotely near a level that can cause human harm.

But some researchers and industry officials argue that the animal data and human blood levels should not justify tagging nail polish with a skull and crossbones and warning consumers to apply deodorant at their own risk. The difference between the level where animals start to show ill effects and the largest doses humans are likely to receive is still large enough, said Gerald McEwan, the vice president of science with the Cosmetic, Toiletry and Fragrance Association, to suggest that even the vainest consumer of beauty products runs little health risk.

McEwan said that the highest dose rodents can tolerate without getting sick -- known as the no-adverse-effect level -- is more than a thousand times higher than the phthalate kick that could be expected by a heavy user of cosmetics. And that, he said, is a conservative estimate.

Cosmetic makers, he said, calculate a risky dose to humans at more than 36,000 times higher than the expected phthalate dose from cosmetics. Policymakers usually look for a margin of safety of 100 times the expected dose.

"Even taking the worst case, we still have a margin of safety over 1,500. It gives us a sense of security that the use of these in cosmetic products is not going to cause any harm," McEwan said. He rejected calls to err on the side of safety and push for replacement chemicals. "The scientific answer is: If it's safe, it's safe. It's not a matter of something being safer."

Although there are other chemicals that can fill the same role as phthalates, most of them don't have a long history of use, and McEwan said that there's little reason to switch to an alternative.

Phthalate opponents say that stance obscures recent science on the topic. Everyday exposures can be higher than the Environmental Protection Agency's safety limit, 100 micrograms per kilogram of body weight a day, according to a memo to the CIR panel by the anti-phthalate coalition. (Industry sources argue that the EPA figure is conservative and that higher doses still don't have the potential to cause harm.) The memo notes that researchers haven't yet found a dose so low that it won't cause male birth defects in rodents. Adding to the concern is the general lack of information about what, if anything, the chemical does in the human body.

"Although we're all exposed to phthalates every day, there has not been a human study," said Jane Houlihan, the vice president for research at Environmental Working Group. "No one has the answers yet, and certainly this panel didn't come up with the answers."

Though preliminary work has been done to assess phthalate levels in humans, there's been no move yet to try to compare those levels to health profiles. That, said Pirkle, will come later, as researchers uncover more information about exposure.

Troubling, too, said Houlihan, is the growing number of products that may cause exposure in humans. While a single spritz of perfume may be of negligible impact, she conceded, added exposure from a variety of medical and household products could tip the balance from safety to danger.

At least one new piece of evidence may help resolve the debate shortly: Next year, the CDC is expected to release much-more-detailed information on phthalates and other chemicals, drawn directly from human urine and blood measurements. That, said Pirkle, should allow scientists to draw better conclusions about the nature of the risks, if any, that phthalates pose.•

Brian Reid is a regular contributor to the Health section.