Myth of the Month, January 2008

“It's been almost 10 years since the U.S. Consumer Product Safety Commission released the results of a landmark study of the chemical diisononyl phthalate (DINP), commonly used to soften plastic toys and other children's products…”
—Playthings Magazine, January 1, 2008

10 years? Wrong. The CPSC released an initial opinion in 1998 on the use of the phthalate DINP in toys. It then proceeded to conduct a comprehensive review that took almost five years. It reviewed all the scientific literature on DINP, and also created an independent panel to study the mouthing habits of children as a way to get a hard fix on just how much exposure young children experienced. The author of the Playthings article made much of the fact that the CPSC was tentative in its initial judgment, using qualifier words such as "few." But being cautious was the proper stance. After the full "landmark" study was completed, the CPSC released its final report and conclusions in 2003, stating that it found "no demonstrated health risk" to children from DINP in toys. No qualifier words there. And just last month, a spokesman for CPSC said it found no reason in the science literature to change that conclusion.

Myth of the Month, December 2007

“A mounting body of scientific evidence suggests that phthalates impede the production of testosterone and disrupt the sexual development of infant boys.”
—The Nation, November 5, 2007

There is no scientific evidence that phthalates impede the production of testosterone in infant boys. None. There is no direct evidence or statistical analysis that claims phthalates have caused any actual damage to male infants, either through direct exposure or exposure of their mothers before they were born. In rats, sometimes; in humans, no. This article, drawn from a book by one Mark Schapiro, is yet another example of how wildly inflated the reporting on one small study by Dr. Shanna Swan has become. That study is actually a statistical analysis that claims to show subtle changes in infants' reproductive systems and to connect this to their mothers' exposure to phthalates. But the study clearly states that it found no actual damage. And it cannot and does not make any claim as to the cause of the subtle changes that were observed - if indeed they are changes at all. The study has been widely criticized for its methods and its inferences, has been set aside by various government agencies as suffering from a “number of limitations” and as “insufficient” for drawing any conclusions. There are legions of other mistakes in the Schapiro book and the article, but this one is at the top of the list for creativity.

Myth of the Month, November 2007

“The U.S. Environmental Protection Agency has asked the National Academies of Science to produce a report on phthalates, a process that could take several years. The National Academies data would help the EPA set a "reference dose" for those chemicals - the maximum amount scientists believe a person could be exposed to in food and water every day without harm.”
—USA Today, October 31, 2007

There already are reference doses for the major phthalates established by the EPA, and the government's own data show that average human exposure is far below those levels. Reference doses, or RfDs, are calculated by taking the highest dose that has no effect on rats, then dividing it by an appropriate safety factor, like 100 or 1,000. The Centers for Disease Control and Prevention has already measured the levels of phthalate metabolites in a cross-section of Americans. Scientists know how to use that information to reveal how much of the various phthalates humans are actually exposed to in their daily lives. The results show that average human exposure is far below the EPA reference doses. To see how human exposure compares to the EPA safety levels, see the tables at http://www.phthalates.org/yourhealth/human_exposure.asp. EPA is currently updating its reference doses.

Myth of the Month, October 2007

“Phthalates…are hormone-mimicking chemicals used to soften various plastic items used daily in most American households.”
—Tyler Morning Telegraph, Texas, September 17, 2007

Even when reporters try to get it right, they are often trapped by the myths that abound about phthalates. In this story, the reporter did do some reporting before setting pen to paper, and even quoted an M.D. advising consumers not to panic over scare stories. But the "hormone-mimicking" myth made it into the story, stated as if it were a fact that of course everyone knows to be true.

But phthalates have been tested on live animals to see if they are capable either of blocking the action of male or female hormones, or imitating them. Studies have not found that they do either - so they don't fit the classic definition of endocrine disruptor. So why do reporters keep recycling the claim that phthalates are "hormone-mimicking?" There may be a reason for this common error. Some phthalates, when administered in very large doses, have suppressed the production of testosterone in rodents. One could call that endocrine disruption, but the distinction between disruption and mimicry is all-important. For example, it is the ability to mimic female hormones that links some natural and synthetic substances to breast cancer. This leads to a compound myth sometimes floated on pressure group Web sites: if phthalates mimic hormones, they might be a player in breast cancer. But there's no support for either part of this claim. In fact, phthalates have been tested in high doses in rodents and have never showed any effect on mammary cells. This being Breast Cancer Awareness Month, it seems only appropriate to point that out.

Myth of the Month, September 2007

“When a fetus is exposed to phthalates, they may cause malformation of the reproductive tract in males and decreased semen quality.”
— Vogue, August, 2007

The writer seems to be referring to a much-criticized study that has been reported as claiming that changes in male infants occurred as a result of phthalate exposures to their pregnant mothers. But that same study explicitly states it detected no "no frank genital malformations or disease." A separate, also much-criticized study claimed a link between adult males with decreased semen quality (all the men in the study were already seeking treatment in a fertility clinic) and current levels of phthalate metabolites measured in their urine. This second study did not claim that in utero exposure to phthalates caused adverse health effects later in adult men. And obviously, there is no study that could show decreased semen quality in fetuses because they are far away from the age of puberty.

Myth of the Month, August 2007

“They're what you smell when you get a new car, pool float or shower curtain;”
— Washington Post, July 22, 2007

This is another myth that refuses to die. For starters, phthalates have little to no odor. What you might smell in a new car, or from a freshly unpacked shower curtain, are some highly volatile compounds used in the manufacturing process. Phthalates used to make some vinyl products flexible are relatively heavy molecules, and not very volatile, so there is not likely to be any significant amount in whatever gasses may be given off in new plastic products. In a recent German study, the interior air of new and ten-year-old cars was heated to 140 degrees Fahrenheit and then tested for its chemical contents. No phthalates at all were detected.

Myth of the Month, July 2007

“Phthalates compose 90% of the chemicals found in household dust.”
— Dr. Martin Donohoe, representing Physicians for Social Responsibility, in testimony to the Oregon legislature

That sounds like a lot, because of the way the statement is packaged. How much of household dust is chemicals? Very little. And how much of that is phthalates? Even less. The most thorough study of phthalates in household dust was done by Oie et al in 1997. It found phthalates both in sedimented dust and in airborne dust. Oie's team added all the phthalates together, and found that they comprise one tenth of one percent of the weight of total household dust. A subsequent study by Greenpeace found the average amount to be less than half of one percent. A risk assessment just published by the European Union's Scientific Committee on Health and Environmental Risks (SCHER) looked at hundreds of components of indoor air and dust and reports that it “… does not find consistent scientific evidence which indicate that phthalates should be high concern chemicals in indoor air.”

Myth of the Month, May 2007

“Frederick vom Saal, a professor of reproductive biology at the University of Missouri-Columbia, said that phthalates...are widely used in cosmetics in the United States although the European Parliament has banned such use.”
— Catholic News Service, May 1, 2007

The phthalate "widely used in cosmetics" is DEP, diethyl phthalate, which is used as a solvent in fragrances. It is not banned in Europe, or anywhere. And it is not linked, as the story implied, to the various health effects seen in laboratory animals from high exposures to some other phthalates. DEP has a very strong safety profile. Dr. vom Saal, who is not a published author on phthalates, may have confused DEP with dibutyl phthalate, DBP, which is used sparingly in nail polish, but not in other cosmetic products. DBP is among hundreds of chemicals banned for use in cosmetics in Europe.

Myth of the Month, April 2007

“Phthalates, linked to reproductive damage, are a common hidden element of fragrances in body lotions, hair sprays, perfumes and deodorants…”
— The Record, New Jersey, March 14, 2007

Yes, a particular phthalate is used in fragrances as a solvent. But no, that particular phthalate is not linked to reproductive damage in humans. It is true that some phthalates have been linked to adverse reproductive health effects in rodents, when given high doses over extended periods of time. But that is not true for DEP, or diethyl phthalate, a common ingredient in fragrances. The Record, an excellent north New Jersey daily, is by no means the only publication to fall prey to this bit of misinformation, which is heavily promoted by the anti-chemical lobby.

In studies, DEP has not produced adverse reproductive effects in animal studies, even at very high doses (maximum tested doses as high as 750 mg/kg/day). These DEP levels are well above potential human exposures from consumer products.

Myth of the Month, February 2007

“Among the chemicals in vinyl are phthalates, which have been linked to early puberty.”
— New York Magazine, Jan 22, 2007

This statement, in an article aptly titled “Indulge Your Paranoia,” features the author-mother worrying whether the vinyl rain shield on her son’s stroller might somehow harm him. Where did she get that idea? Mostly from a 2000 study exploring early puberty — but in young girls, not boys. Scientists have since considered this study to be invalid because it was conducted incorrectly. (See McKee, R. (2004). Phthalates and Early Thelarche. Environmental Health Perspectives 112:A541-543.)

Media stories often suggest that the phthalates people encounter in a typical day, in ordinary flexible vinyl products, are, or could be, resulting in harm to health. These types of claims just aren’t substantiated. While we know that some phthalates have shown negative health effects in rodents, this has occurred when administered in huge doses over extended periods of time. The federal government, through the Centers for Disease Control, has told us what the actual, real-world exposures to phthalates are — and they’re tiny compared to anything the rats saw.

The interesting part of the story? When the writer replaced the vinyl rain shield with a substitute product, it didn’t work, and her baby was drenched.