As "The Graduate" once predicted, plastics have become ubiquitous. Unfortunately a common chemical additive of this now-indispensible material, called phthalates, is raising some concerns. While recent research suggests that these chemicals may be dangerous to human health, a little knowledge can go a long way in helping to weigh the risks and make safe choices.
Phthalates (pronounced “thalates”) are plasticizers that are commonly used to make polyvinyl chloride (PVC) plastics pliable. A few of the products made from PVC softened with phthalates include shower curtains, floor tiles and window blinds. Phthalates have been found in some soft plastic children’s toys, such as teethers and pacifiers (despite a much-touted voluntary phase-out several years ago), as well as some sippy cups and nipples for bottles. While plastic food containers typically have a recycling number embossed on the bottom — PVC is #3 — many other products may only note that they’re made of vinyl on their packaging.
Phthalates are sometimes added to other common products as well, such as caulk, paint, cosmetics and toiletries. They make nail polishes flexible and durable, help lotions penetrate more deeply into the skin, cause fragrances to evaporate more slowly, and enable colors to last longer. Food wrap made of PVC is still used in food-service settings, like deli counters, although it’s largely been phased out of consumer products. PVC is also used to make soft plastic medical equipment, like bags for blood and intravenous fluids, tubing and more. And if you happen to have an invitingly soft “jelly rubber” or “cyberskin” erotic toy in your bedside drawer, chances are it’s made from vinyl that’s been softened with phthalates.
Clearly, phthalates are very useful chemicals, but here’s the bad news: In some studies on rats and mice, exposure to high levels of phthalates damaged the liver, kidneys and reproductive system. Reports published in 2002 and 2003 suggested that minute levels of phthalates were linked to DNA damage in human sperm. A 2005 study by researchers at the Harvard Medical School, two Harvard hospitals, and the Centers for Disease Control and Prevention found that infants treated in intensive care units with equipment containing phthalates had high levels of the chemical in their bodies. And in another 2005 study, University of Rochester researchers found that exposure to everyday levels of phthalates in utero affected the reproductive development of infant boys: Mothers with higher exposures had sons with certain genital irregularities, as well as smaller penises than those born to mothers with the lowest exposures. These boys were also more likely to have an undescended testicle.
Phthalates generally enter the body via inhalation or absorption; heat, agitation and age can accelerate their escape from plastics. That new-car smell everyone loves? It comes from phthalates. A car dashboard made with PVC can heat up to 200 degrees on a hot, sunny day, and UV rays accelerate outgassing. Phthalates are also lipophilic, or attracted to fats. Fat present in blood can actually draw them out of IV bags, for example, and carry them into the body.
So how much exposure is too much? Unfortunately, no one is quite sure what the safety threshold is. The amount of phthalates you might take in from any one source — an application of nail polish, the outgassing from your vinyl beach chair — is probably small. But little research has been done on what our cumulative exposure may be from all the phthalates in our homes, workplaces and schools. Given some of the alarming research findings of the past few years, though, why aren’t phthalates restricted until we know more?
“There’s a misunderstanding the public has that when they go to the store and buy a product, someone has tested it and deemed it safe,” says Joel Tickner, Sc.D., an environmental health professor at the University of Massachusetts, but “the sad reality of our current system is that there’s no government requirement to demonstrate safety before chemicals are used in products.” Generally, under federal laws, a substance has to be proven harmful to be restricted or banned, rather than proven safe before use. Not only that, but it must be shown to be harmful enough that the benefits of regulating it significantly outweigh the costs of the regulation to industry. By contrast, in the European Union, chemicals generally need to be proven safe before they’re approved for use, a standard called “the precautionary principle.” Two kinds of phthalates commonly used in cosmetics here have been banned by the European Union.
But many U.S. advocates are working to change the situation, despite the lack of government oversight. A coalition called Health Care Without Harm is fighting for safer alternatives to PVC in medical gear. The group scored a success last year at its annual conference when two top medical-device manufacturers announced new lines of equipment made without PVCs or phthalates. And there’s activism on the personal-care-product front as well. In 2002, a coalition called the Campaign for Safe Cosmetics had 72 products tested, including lotions, deodorants, and hairspray, and found that 52 contained phthalates. In 2003, the nonprofit Environmental Working Group created the Skin Deep Database, which rates 15,000 personal-care products based on the ingredients listed on their labels. The group found 89 nail polishes and nail treatments that listed phthalates, says Sonya Lunder, senior analyst with EWG, “but tests we’ve commissioned in the past, and general knowledge, indicate that many more use phthalates and don’t put them on the label.” This is because of a loophole in FDA regulations: Fragrances are considered part of trade secrets, so companies are not required to reveal every single ingredient in them.
Many safe-cosmetics advocates want European manufacturers to sell their phthalate-free formulations to U.S. consumers as well. If they can do it cost-effectively in Europe, they reason, they can do it here. Industry, however, resists. John Bailey, Ph.D., executive vice president for science at the Cosmetic, Toiletry and Fragrance Association, contends that current U.S. laws adequately protect consumers, and that phthalates in cosmetics are safe. Recent research implicating phthalates in hormone disruption fails to balance the hazard versus the risk, says Bailey, who compares phthalate use to driving a car: Sure, moving across the landscape in a metal box at 65 miles an hour is inherently dangerous, but the actual probability that you will get hurt in an auto accident is very small. Similarly, Bailey says, while phthalates can be hazardous, in typical daily uses they present little risk.
For many of us, it’s going to come down to deciding for ourselves: Do we consider phthalates safe enough just because they haven’t been definitively proven dangerous? Or would we rather follow our own precautionary principle and avoid them until they’re proven safe?
Keep in mind
Plastic bottles marked with recycling symbol #1 are made from polyethylene terephthalate (PET or PETE). Containers made from PET are often used for products like water, ketchup, milk, and vegetable oil. Despite the “phthalate” in its name, PET is chemically different from PVC and is not associated with phthalate leaching. Some experts still say it’s best to avoid reusing disposable PET containers, and to avoid heating foods in plastics. It’s also worth noting that some plastic food containers may contain a substance called bisphenol-A (BPA), which, like phthalates, has been implicated as an endocrine disruptor. If you want to limit BPA exposure, one easy way is to minimize or avoid using polycarbonate plastic bottles (marked with #7).
Story by Emily Gertz. This article originally appeared in Plenty in September 2008. The story was added to MNN.com.