The Elements

Claims about the risks of chemicals in plastics don’t hold water. The FDA is required to consider all such substances since it regulates water as a food product, and chemicals coming from the bottle would be considered food additives and regulated as such. The FDA ensures that such chemicals never reach levels of concern. And in fact, the FDA could not find any documented health problems associated with such chemicals.

Nonetheless, activists regularly suggest that the public is at risk from trace chemicals coming from plastic bottles of all kinds. One chemical found in plastics that activists claim poses a risk is Bisphenol A, which is used to make polycarbonate containers, such as baby bottles, reusable water bottles (Nalgene water bottles, which ironically environmentalists promote when they call for reusable bottles), five-gallon bottles used for large water coolers, as well as some other products. Activists say that BPA leaches out into the water or other food items in containers and threatens to impact public health, largely by disrupting endocrine systems.

But the best science on the topic shows that the trace levels of BPA that currently exist do not pose any significant health risk. For example:

* After an exhaustive review of the data, the FDA concluded: “An adequate margin of safety exists for BPA at current levels of exposure from food contact uses.”

* In July 2008, the European Food Safety Authority reaffirmed a 2006 study on BPA that found human exposure to the substance through consumer products is not high enough to have any adverse impacts.

* Another comprehensive review of the issue conducted by the National Toxicology Program (NTP) at the National Institutes of Health, came to similar conclusions, finding no direct evidence of any problems among humans. This report expressed minimal to negligible concern for almost all factors. It called for more research in one area and expressed only “some concern” (more significant findings would state “concern” or “serious concern”) because rodent studies showed some association of potential effects on behavior. Yet as NTP noted: “These studies in laboratory animals pro¬vide only limited evidence for adverse effects on development and more research is needed to better understand their implications for human health.” Indeed, the relevance of the impacts on rodents to the potential impacts on humans is questionable.

Despite extensive study and the inability of anyone to document problems with Bisphenol A, the substance is the subject of much hype and press coverage. For example, a headline story in the Washington Post on the draft of the NTP report read: “U.S. Cites Fears on Chemical in Plastics.” The story suggested that government researchers had made a new and major finding on BPA. Yet instead of discovering a problem, the draft brief—like the final report—underscored the fact that researchers have been unable to find any impact on humans from the chemical. The key conclusions in the brief are as follows:

“The NTP has negligible concern that exposure of pregnant women to bisphenol A will result in fetal or neonatal mortality, birth defects or reduced birth weight and growth in their offspring.”

And:

“The NTP concurs with the conclusion of the CERHR Expert Panel on Bisphenol A that there is negligible concern that exposure to bisphenol A causes reproductive effects in non-occupationally exposed adults and minimal concern for workers exposed to higher levels in occupational settings.”

Yet some people still suggest that BPA can mimic endocrine related chemicals and impact public health. The Competitive Enterprise Institute’s Jonathan Tolman helps clarify such risks, showing that they are inconsequential. He notes:

“We are constantly exposed to a variety of other estrogen mimicking compounds in our everyday diet, not from manmade chemicals, but from compounds produced by plants themselves — so called phytoestrogens. All legumes, for example contain estrogen mimicking compounds with soy products being one of the largest contributors.

It would have been helpful [to compare] the levels of exposure of phytoestrogens to the level of exposure to BPA in order to give readers a basis of comparison with which to judge the risk. In 1999, the National Academy of Sciences published its study, Hormonally Active Agents in the Environment, and estimated the potential daily human exposure of various estrogens. According to the NAS study the estimated exposure to BPA in food cans was 6.3 micrograms per day, and BPA in beverage containers was less than 0.75 micrograms per day. By comparison, the exposure to phytoestrogens was estimated at 1,000,000 micrograms per day. Given the huge relative disparity between the exposures to phytoestrogens as compared to BPA concentrations, the risk of BPA in consumer products appears to be about the same as tablespoon of soymilk.”

Moreover, the FDA has repeatedly made clear that it does not consider Bisphenol A to be a problem. It notes:

“Based on our ongoing review, we believe there is a large body of evidence that indicates that FDA-regulated products containing BPA currently on the market are safe and that exposure levels to BPA from food contact materials, including for infants and children, are below those that may cause health effects. However, we will continue to consider new research and information as they become available. This position is consistent with two risk assessments for BPA conducted by the European Food Safety Authority (EFSA) Scientific Panel on Food Additives, Flavourings, Processing Aids and Materials in Contact with Food and the Japanese National Institute of Advanced Industrial Science and Technology. Each of these documents considered the question of a possible low-dose effect and concluded that no current health risk exists for BPA at the current exposure level.”

However, the FDA provided a silly disclaimer at the bottom of this document which reads: “At this time, FDA is not recommending that anyone discontinue using products that contain BPA while we continue our risk assessment process. However, concerned consumers should know that several alternatives to polycarbonate baby bottles exist, including glass baby bottles.” The idea that a public health agency would suggest that glass bottles—which can easily break and injure a child—might be a better alternative than unbreakable, lightweight plastic bottles just goes to show how odd the debate has become.

Another concern about plastic water bottles is being raised in e-mail alerts that tell people they can get cancer from bottles of water especially if they are left in the car or put in the freezer. Some claim that these problems were reported by The Bloomberg School of Public Health at Johns Hopkins University. However, Johns Hopkins issued a statement noting that these e-mails were a hoax and not endorsed by the school.

Nonetheless, the e-mails indicate that the extreme temperatures release chemicals from the plastics into the water. One chemical they claim that the bottles release is called Di(2-ethylhexyl) (DEHA), which is an additive used to make certain plastics. In addition the criticisms issued by Johns Hopkins about these claims, the American Cancer Society also refutes the DEHA claim noting that DEHA isn’t even used to make plastic water bottles. It also points out that the EPA and the International Agency for Research on Cancer (IARC) of the World Health Organization (WHO) both have reported that there is no good evidence that DEHA produces significant health or environmental effects. After studying the issue in 1995, the EPA concluded that DEHA “cannot reasonably be anticipated to cause cancer, teratogenic effects, immunotoxicity, neurotoxicity, gene mutations, liver, kidney, reproductive, or developmental toxicity or other serious or irreversible chronic health effects; and …it cannot reasonably be anticipated to cause significant and serious adverse effects on the environment.” (see: U.S. Environmental Protection Agency, Federal Register 60, no. 7, August 1, 1995: 39132-39134.)

Similarly the IARC monograph on the topic reports: “No epidemiological data relevant to the carcinogenicity of di(2-ethylhexyl) adipate were available. There is limited evidence in experimental animals for the carcinogenicity of di(2-ethylhexyl) adipate.” Its overall evaluation is: “Di(2-ethylhexyl) adipate is not classifiable as to its carcinogenicity to humans.”

Similarly, Johns Hopkins notes that there are no dioxins in plastic water bottles to worry about, despite claims in various e-mail alerts.” “There are no dioxins in plastics. In addition, freezing actually works against the release of chemicals. Chemicals do not diffuse as readily in cold temperatures, which would limit chemical release if there were dioxins in plastic, and we don’t think there are,” notes Rolf Halden, Ph.D., P.E., assistant professor in the Department of Environmental Health Sciences and the Center for Water and Health at the Johns Hopkins Bloomberg School of Public Health.

Halden offers a perspective as well: “Don’t be afraid of drinking water. It is very important to drink adequate amounts of water and, by the way that’s in addition to all the coffee, beer and other diuretics we love to consume. Unless you are drinking really bad water, you are more likely to suffer from the adverse effects of dehydration than from the minuscule amounts of chemical contaminants present in your water supply. Relatively speaking, the risk from exposure to microbial contaminants is much greater than that from chemicals.”

Environmental activists also suggest that we should worry about the effects of chemicals called phthalates that are used in a variety of products. Phthalates are a group of substances used to make polyvinyl chloride (PVC) plastics flexible, and they are found in medical devices such as vinyl tubing, home siding, plastic pipes, toys and other items. Phthalates have been in use for about 50 years without any reported human health problems.

Ironically, the greens urge people not to drink bottled water to avoid these chemicals when in fact they are not even used in the bottles. Yet recently a staff attorney for the NRDC reported to congressional committee that we should fear phthalates in our bottled water because the phthalate DEHP—(2-ethylhexyl) phthalate—is used for the gasket of the plastic cap. Among her complaints was the fact that the FDA does not impose the EPA drinking water standard for phthalates to bottled water.

These activists are clearly grasping at straws by suggesting that we would worry about a small piece of plastic used inside the cap to help keep the seal from leaking. Contact with the surface of the water in this case, would be small and occurs only when the water bottles are not upright. Accordingly the exposure level from this small, thin piece of plastic is tiny. In fact, the NRDC study on bottled water only found two samples out of 1,000 that contained phthalates. One sample was in compliance with EPA’s standard and the other was above it by only a few parts per billion. It is worth underscoring the fact that NRDC did not detect phthalates in 99.8 percent of the samples, which is why FDA does not apply the EPA standard for phthalates. The phthalate standard is simply not relevant because exposure level in bottled water is slim to none.

In any case, there is little need to worry about the impacts of phthalates from other consumer products where exposure might be more than that found from a gasket in a bottle cap. According to the Agency for Toxic Substances and Disease Research (ATSDR) at the CDC:

“DEHP, at the levels found in the environment, is not expected to cause adverse health effects in humans. A man who voluntarily swallowed 10 g (approximately 0.4 ounces) of DEHP had stomach irritation and diarrhea. Most of what we know about the health effects of DEHP comes from studies of rats and mice that were given DEHP in their food, or the DEHP was placed in their stomach with the aid of a tube through their mouth. In most of these studies, the amounts of DEHP given to the animals were much higher than the amounts found in the environment. Rats and mice appear to be particularly sensitive to some of the effects of DEHP. Thus, because certain animal models may not apply to humans, it is more difficult to predict some of the health effects of DEHP in humans using information from these studies.”

ASTDR notes that long-time exposure of DEHP to rats and mice has produced cancer in the rodents. Such studies led the Department of Health and Human Services to report that DEHP “reasonably be anticipated to be a human carcinogen” and the U.S. EPA to classify it as “a probable human carcinogen.” However, ASTDR points out that basing such classifications on rodent tests is questionable “because of the differences in how the livers of humans and primates respond to DEHP as compared with the livers of rats and mice.” For that reason, the International Agency for Research on Cancer (IARC)—a research body of the World Health Organization—changed its classification for DEHP from “possibly carcinogenic to humans” to “cannot be classified as to its carcinogenicity to humans.” Specifically, IARC notes: DEHP is”not classifiable as to its carcinogenicity to humans” because “the mechanism by which di(2-ethylhexyl) phthalate increases the incidence of hepatocellular tumours in rats and mice is not relevant to humans.”

In addition, a 15-year scientific evaluation of DEHP produced by the European Union assessed the impacts of DEHP use in the medical field. DEHP is used for plastic tubing, medical devices and blood bags. As a result, the highest human exposures to DEHP occur via medical equipment, particularly for individuals who are regularly exposed—such as kidney dialysis patients. Yet the EU researchers could not find any measurable adverse health effects of DEHP to individuals exposed to it at the highest levels. They do note its importance and value in providing important medical treatments. A summary of the report says that it cannot show that there is no risk (since no one can prove a negative), but they also could not find any health effects from DEHP exposure even among individuals who are most exposed. The report notes:

“The general view of DEHP toxicity is therefore that mechanisms for adverse effects do exist in rodents, but that these do not appear to be of great significance in non-human primates and that the evidence that such mechanisms could be operative in humans is lacking. … However there are no reports concerning any adverse effects in humans following exposure to DEHP-PVC, even in neonates or other groups of relatively high exposure. So far, for example, there are no indications that neonates of high DEHP exposure have any altered long-term fertility patterns. … There are also other groups of patients or individuals who experience prolonged periods of elevated DEHP exposure, including patients on haemodialysis or in receipt of repeated blood product transfusions, where risks and benefits should be considered carefully. At the present there is no evidence that any of these groups do experience DEHP related adverse effects.”

Unfortunately, groups continue to cite periodic studies that they say raises doubts about plastic bottles and other plastic products. However, such studies are often misinterpreted in the public press and single study that might raise issues for further research should not be used to dismiss decades of research. Policymakers and others should view such claims with caution rather than allow activists to generate unwarranted fears.