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Roman women slowly poisoned themselves with generous slatherings of white lead foundation. Medieval Italians sensuously dilated their pupils—and blinded themselves—with an extract of belladonna. And the ladies of Queen Elizabeth’s court wore thick layers of red lip color made from toxic mercury compounds. All apparently were under the impression that their daily beauty regimen was 100 percent safe. Which begs the question: Are we similarly deluded today?

Cosmetic conflict

Even if you don’t wear much makeup, chances are that you’re washing your hair with shampoo and conditioner, toning down your underarm stink with deodorant, and attempting to stave off old age with moisturizer. According to the Environmental Working Group (EWG), a watchdog organization that monitors the use of chemicals in everyday life, those simple actions add up fast. A survey the organization conducted in 2004 showed that American women use an average of 12 hygiene products each day. By the EWG’s count, that translates to more than 150 ingredients being absorbed through the skin, inhaled through the nose or inadvertently licked off the lips.

As far as the EWG is concerned, all this represents a massive risk to public health. “Essentially, we’re conducting a giant experiment,” says Jane Houlihan, the organization’s vice president for research. “People are being exposed to hundreds of chemicals. Every person is full of complex mixtures and the health consequences are completely unknown.” Particularly of concern to the EWG and other activist groups are two families of chemicals known as phthalates and parabens.

Phthalates are a common ingredient in things like hairsprays, nail polish and perfume, where they function as a plasticizer—keeping the mixtures flexible while also helping them remain sticky. Parabens are preservatives that keep fungus and bacteria at bay in a wide variety of cosmetics and hygiene products.

The EWG points out that research on rats has shown both chemical families to be carcinogens. A 2004 study published in the journal Reproductive Technology linked phthalates with reproductive anomalies, and a study published that same year in the Journal of Applied Toxicology detected parabens in breast cancer tissue. In fact, parabens and phthalates were among the chemicals banned by the European Union in 2003. A quick Web search will turn up a number of organizations that have extrapolated this research into warnings that makeup or deodorant are the cause behind breast cancer.

Naturally, this makes the cosmetics aisle seem pretty scary. But not all scientists agree that the danger is so great. The Food and Drug Administration officially classifies parabens and phthalates as safe, because the research has yet to prove a causal link between the chemicals and diseases in humans. As it turns out, rats, while convenient for research, don’t actually process chemicals the same way we do. So what’s deadly to them could easily be harmless in us. Other organizations—like the industry-run Cosmetics Ingredient Review board and the independent American Council on Science and Health—agree, pointing out that the amounts of phthalates and parabens used in cosmetics are far, far lower than even the amount needed to induce cancer in rats.

Pretty is as pretty does

So, who’s right? The answer probably falls somewhere in between. “There’s a lot of people talking black and white, this is good or this is bad,” says Urvashi Rangan, an environmental health scientist who works with Consumer Reports magazine and its parent organization, the Consumers Union. “But a lot of the ingredients in cosmetics come down into a very gray zone.”

To Rangan, the fact that cosmetics use very low levels of chemicals doesn’t mean there’s zero risk. Instead, it means that we need more research to understand the effects of chronic, long-term exposure. On the other hand, chemicals aren’t inherently bad and Rangan thinks it’s inaccurate to say that using certain cosmetic products could be deadly.

“We don’t know all the reasons cancer happens,” she says. This means it’s impossible to identify a certain chemical as the precise—and sole—cause of a cancer. "To say these products are going to kill you is an overstatement. It's not likely that there's going to be a single reason behind why someone gets cancer."

Instead, Rangan says, the real problem lies in how we currently address the potential dangers associated with these chemicals. “Europe tends to operate on the precautionary principle and they tend not to make things legal until there’s a proof of safety,” she says. “Here, it’s the opposite. In order for the FDA to ban a chemical used in cosmetics it has to be proven harmful.”

And proving harm is tough. Usually, it requires thousands of people to develop a problem that can be linked definitively to a specific product or ingredient. Currently, the FDA has no authority to review cosmetics before they go to market and can only ban ingredients after problems arise. So, while most cosmetic products have been tested for short-term safety, their long-term effects are almost completely unknown. “There’s very little data to suggest safety or harm,” Rangan says. “There’s just a big question mark there.”

For now, whether or not you should keep using your favorite products depends a lot on how you use them and how much risk you’re comfortable with. For instance, occasionally using eyeliner with a questionable ingredient probably isn’t dangerous, but if you’re applying heavy amounts of a suspect lotion every day, you might want to consider taking steps to reduce your exposure.

One way to help gauge your risk is by looking up your brands on Skin Deep, the Environmental Working Group’s online database, which analyzes all the various risk factors associated with specific products.         

Under suspicion:4 ingredients to keep an eye on

Parabens

What They Are: Preservatives that keep products bacteria-free.

Where You’ll Find Them: Cleanser, hand soap, moisturizers and toothpaste

Names They Go By: Methylparaben, propylparaben, and butylparaben.

What’s the Concern: Parabens can mimic natural hormones, including estrogen. Disruption of sex hormones increases the risk of certain cancers.

Phthalates

What They Are: Plasticizers that increase flexibility and strength.

Where You’ll Find Them: Hair spray, nail polish and perfumes.

Names They Go By: Di(2-ethylhexyl) phthalate and diethyl phthalate are common in fragrances, while dibutyl phthalate appears in many nail polishes.

What’s the Concern: Can also mimic sex hormones and may be able to affect growth of reproductive systems in fetuses. Used in hundreds of non-cosmetic plastic products, so exposure is increased.

Coal tar

What It Is: The liquid by-product of coal distillation.

Where You’ll Find It: Shampoos aimed at killing head lice or reducing dandruff and some dark hair dyes.

What’s the Concern: Extremely carcinogenic in rodents. Might also be linked to liver disease.

Toluene

What It Is: A solvent, basically a liquid that dissolves other liquids or solids.

Where You’ll Find It: Nail polish and nail polish remover.

Name It Goes By: It might appear under the names methylbenzene or phenylmethane.

What’s the Concern: Breathing in the fumes can damage kidneys and cause birth defects. People who work frequently with nail products are at most risk.