Q. What are Phthalates?
A. Phthalates are a large family of compounds used in a wide variety of everyday products. They are colorless, oily liquids with little or no odor and low volatility.

Q. What are they used for?
A. The dozen or so phthalates in use today find thousands of applications. Their chief use is to make vinyl soft and flexible, without sacrificing its durability. They are used as softeners (or plasticizers) in toys, cars and products found in the home and in hospitals. For example, they are an important ingredient in vinyl medical devices used to help save lives. One member of the phthalate family is used in perfumes and other personal care products to make their fragrances last longer. Another type of phthalate is used in items such as tool handles and nail polish to help resist chipping.

Q. Are they safe?
A. Regulatory agencies and independent authorities have found phthalates to be safe as used in vinyl products and personal care products. There is no reliable evidence that any phthalate has ever caused any harm to any human in their fifty-year history of use. Phthalates are one of the most thoroughly tested families of compounds in use today. An immense amount of information on their safety profiles is available to users.

Q. Who says so?
A. The European Union has conducted extensive safety reviews of all the major phthalates, and has found they present no concern to the general public in their current uses. Its reviews specifically cover uses in nail polish and in toys.

The U.S. Consumer Product Safety Commission has found that the principal phthalate used in toys presents “no demonstrated health risk” to children. The U.S. Centers for Disease Control and Prevention (CDC) has tested thousands of Americans for evidence of exposure to phthalates (as well as to more than one hundred other chemicals and elements). CDC data show that average human exposure is far below levels set by the U.S. Environmental Projection Agency as protective of human health.

Q. Why have phthalates been banned from personal care products in Europe?
A. Not because any human health effects have been found. The European Cosmetics Directive says that any substance known or strongly suspected to have certain health effects in laboratory animals—even if this occurs only at extremely high doses—is assumed to present similar risks to humans, and may not be used in cosmetics. The directive is not based on any evidence that there is any actual risk to humans. In fact, an EU safety review states that there is “no concern for consumers” who use nail polish containing the phthalate DBP.

Q. Why have some phthalates been banned from use in toys in the EU?
A. The European legislature voted to pass that ban, even though the draft conclusion of an exhaustive safety review of the principal phthalate used in toys stated it was “unlikely to pose a risk” even for newborns. In other words, it was a political decision, not a regulatory one based on science.

Q. The EU risk assessments studied the effects of each phthalate individually. But shouldn’t their effects be added and studied as a whole, because various phthalates can act in the same ways on organisms?
A. Even if you add up the effects of the different phthalates that might be expected to act in the same way on organisms, data from the federal government’s CDC tells us that exposure is still below federal safety levels.

Q. But we are exposed to them every day, in many ways. Doesn’t that add up to trouble?
A. We are exposed to lots of things every day. But phthalates do not build up in the body the way certain other substances do. The process of breaking them down begins within minutes, and their half lives are measured in hours.

Q. Isn’t it true that phthalates cause health problems in laboratory animals?
A. Some—not all—phthalates interfere with the development of the reproductive system of male rodents when administered in huge doses—doses far larger than CDC data tells us humans experience. Rodent effects are not necessarily relevant to humans.

Q. What do phthalates do to rodents?
A. Researchers believe that extremely large doses of certain phthalates suppress the production of testosterone, which is necessary for the normal development of the male reproductive system. The doses that result in these effects are orders of magnitude larger than the exposures humans receive. There is no evidence that this occurs in humans.

Q. Does the same thing happen to humans?
A. There is no reliable evidence that it does. There is some evidence that it does not. A small study of children who were highly exposed through life saving medical devices as infants found no ill effects as teenagers.

Q. Is there any evidence that phthalates don’t affect humans?
A. Tests on male marmosets, which are primates, concluded that even huge doses administered from weaning until sexual maturity had no effect on their reproductive organs. Other studies indicate that humans do not absorb phthalates as readily as rodents do. Humans break them down and excrete them much more readily than rodents do. This evidence suggests that rodent effects may not apply to humans.

Q. Haven’t recent studies shown phthalates to have effects on human sexual development or function?
A. The National Institutes of Health, through its National Toxicology Program studies, has reviewed all studies claiming to show human effects, and in late 2006 called them “insufficient” to warrant drawing any conclusions. All such studies are statistical in nature—that is, they claim to show a correlation between phthalate exposure and certain health effects. But flaws are common, and in these cases, flaws make the results questionable. And none of them claims that phthalates caused any health effect—just that they are statistically correlated with the effects. Such correlations can turn out to be statistical flukes.

Q. Does that include the Swan study?
A. That’s certainly what many experts think. The study claims to show certain changes—not actual damage—in the reproductive development of infants, correlated to exposure of their mothers to a combination of four phthalates. Dr. Rebecca Goldin, a Ph.D. mathematician at Statistical Assessment Services (STATS), asked about Swan’s study, “how much data fiddling was required to find a result?” Others have criticized the study’s methodology, its clinical data, and even its biological plausibility.

Q. Aren’t phthalates endocrine disruptors?
A. In lab tests with rodents, phthalates do not block the action of male or female hormones, or mimic their behavior.

Q. Don’t they cause cancer?
A. The International Agency for Research on Cancer, an arm of the World Health Organization, says DEHP is “not classifiable” as a human carcinogen. The basis for that decision is ample evidence that the biological process leading to cancer in rodents does not occur in humans.

Q. Haven’t phthalates been linked to asthma?
A. Some claims to that effect have been made, but recent laboratory studies have shown that phthalates do not trigger immune responses in rodents, and do not intensify an existing asthma attack. Phthalate levels in house dust have been shown to be very low.

Q. Why do you claim that state or local bans on the use of phthalates in toys are illegal?
A. Many federal laws provide that when a federal regulatory agency has taken an affirmative action on a particular substance for a particular risk, states or localities cannot then regulate it. That is the case here—the CPSC, a federal regulatory agency, has reviewed the use of DINP, the principal phthalate used in toys, and found “no demonstrated health risk.”

Last Updated: February 09, 2007