Hi, everyone. We’re please to share with you this updated summary by Dr. David Parkhurst of the current state of knowledge concerning the safety of polycarbonate plastic when used for storing water and other consumables. In addition, new signs will soon be placed in the stores, providing a summary of this information as well as sources of additional information.
Are polycarbonate water bottles safe?
In the past Bloomingfoods has believed that polycarbonate plastic containers were ideal for the storage of our filtered water, and indeed this kind of plastic was for a time considered to be safe for water and food. However, over the past decade or so, research results have accumulated, indicating that like many plastics, polycarbonate containers may transfer an undesirable compound into their contents.
The information brochures we offered earlier contained information regarding polycarbonate plastic bottles that can no longer be considered correct. In particular, these two statements about polycarbonate jugs require modification and explanation:
1: “Unlike PVC jugs, there is no leaching of odors or chemicals from jugs.”
2: “To sterilize: Use ½ teaspoon (or just a few drops) household bleach per gallon of water. Swish around and let stand 3 minutes. Pour out and rinse well. Air dry, then SEAL.”
Recent summaries provided by scientific panels that met in late 2006 (see below) have concluded that:
1. A compound called bisphenol A (BPA) does leach from various polycarbonate materials into water and other contents, especially as the bottles age or are damaged or bleached. Bleaching is not recommended.
2. This compound has been shown to act as a synthetic estrogen in numerous animal tests, causing a wide variety of undesirable health responses in the test animals.
3. Effects in humans are less well known, but some of the researchers are concerned that similar responses could happen with people. It is, of course, much harder to study health effects of chemicals in people.
4. Pregnant women, and women who might someday become pregnant, should be especially cautious about ingesting BPA.
5. Bloomingfoods has ordered glass bottles as an alternative, and is looking into finding bottles made from a different, safer plastic as well.
NEW INFORMATION AS OF SEPTEMBER 6, 2008
To add to that earlier information, here are some quotes from a New York Times editorial of this date:
"What do you do when one arm of the government says everything is O.K. and another tells you to watch out? That is what is happening with bisphenol-A — a chemical used in many plastics and epoxy resins now found in baby bottles and liners for canned goods. The answer is a truism in every family rulebook — when in doubt, especially when it comes to children, err on the side of caution. That means it is a good idea to keep the young away from bisphenol-A, or BPA. "
"The Food and Drug Administration said last month that the small amounts of BPA that leach out of containers and into food or milk are not dangerous. Then this week, the National Toxicology Program, the federal agency for toxicological research, reported that their research shows “some concern” about the effects of BPA on the brain development and behavior of fetuses and young children. "
"A new study by the Yale School of Medicine is cause for even more concern. In tests on primates, researchers found that BPA “causes the loss of connections between brain cells” that could cause memory or learning problems and depression.
"John Bucher, the associate director of the toxicology program, said there is still considerable uncertainty about whether the changes seen in animal studies are causing the same problems in humans. “But we have concluded that the possibility that BPA may affect human development cannot be dismissed.”
Scientists from the toxicology offer this advice:
¶ Watch for the numeral 7 on the bottom of plastic containers. That often means they contain BPA.
¶ Search for baby bottles and other baby products that are BPA-free.
Some states are considering bills to restrict the use of BPA for the young, and Congress is assessing several possible remedies including a BPA ban in children’s products or a ban on BPA in packaging that touches food [emphasis added]. The best effort, however, would be the Kid-Safe Chemicals Act. It would require that children’s products are proved safe before they are sold, not — as with BPA — the other way around.?
Research has shown that a chemical substance known as bisphenol A (BPA), from which polycarbonate bottles are made, does leach, generally in very small amounts, from polycarbonate bottles into food and water or other liquids that they contain. (These studies were not necessarily performed on the specific brand of bottles sold by Bloomingfoods.) This is potentially of concern, because BPA has been shown to act as a synthetic estrogen in animal tests. The amounts leaching out are likely negligible in new bottles, but as bottles age, are subjected to heat or harsh detergents, are scratched, or are bleached, then amounts leached may increase.
Because bleaching may increase the transfer of BPA from the bottles into their contents, use of chlorine bleach is definitely not recommended, in contrast to Statement No. 2 above from the brochures provided by Mountain Fresh prior to October 2007.
Four US government agencies including the National Institute of Environmental Health Sciences convened 38 scientists in Chapel Hill, NC, in November 2006 to consider the health effects of BPA. The results of that meeting are more up-to-date than many earlier reports.
On the leaching question, Vandenberg and co-authors (2007⎯see the references below), some of the scientists at the Chapel Hill meeting, stated that "BPA has been shown to leach from food and beverage containers, and some dental sealants and composites under normal conditions of use." Thus, Statement No. 1 from the Mountain Fresh brochure cannot be considered valid. The question then becomes, why does that matter?
These authors went on to describe numerous specific undesirable health effects of BPA on animals other than humans that have been identified in laboratory research:
“There are now over 150 published studies describing low-dose BPA effects in animals, including prostate weight and cancer, mammary gland organization and cancer, protein induction in the uterus, organization of sexually dimorphic circuits in the hypothalamus, onset of estrus cyclicity and earlier puberty, body weight, genital malformations and others ….”
Many of those effects were found in animals exposed to BPA levels lower than the US government’s reference dose (a supposed safety level for humans, established in 1988) of 50 micrograms per kilogram of body weight per day. Interestingly, the European Union uses a value of 10, allowing only 1/5 the exposure allowed by the US reference dose. The EU standard was established in 2002.
Because these kinds of effects cannot be studied directly in humans, less is known about the toxic effects of BPA, at the levels in our bodies, on humans. Kuehn (2007) reported as follows on the conclusions of second study panel:
“Another panel, convened in mid-August by the National Toxicology Program (NTP) Center for the Evaluation of Risks to Human Reproduction, reviewed about 500 studies (http://cerhr .niehs.nih.gov/chemicals/bisphenol /draftBPA_MtgSumm080807.pdf). Although the panel rated the likelihood of human reproductive problems as ‘minimal’ or ‘negligible,’ based on existing studies, it did have ‘some concern’ that exposure could have neurological or behavioral effects in pregnant women, fetuses, infants, and children.”
“One reason for the differences in the groups’ conclusions is that the NTP panel chose to exclude studies in which animals were exposed to BPA through injections.”
The panel justified those exclusions because humans are usually exposed to BPA by ingestion, and there is some loss before the substance enters the bloodstream. However, a fetus in the womb can receive BPA directly across the placenta.
Kuehn (2007) also noted that “The panel identified several other areas where more research is needed. These include human research involving occupational exposure to BPA; studies of how BPA is metabolized in pregnant women, developing fetuses, infants, and other groups; and further investigation into potential effects of exposure during development and at other life stages, [Dr. Jane Adams] said.”
Because of these concerns, many Bloomingfoods customers (especially pregnant women and those of child-bearing age) will likely want to avoid regular use of polycarbonate bottles. A further consideration is that we are all exposed to other synthetic estrogens, and no one knows the extent to which these may interact.
Bloomingfoods has ordered glass bottles as one alternative, and is looking into alternatively plastics, such as high-density polyethylene (HDPE) which is thought not to give off estrogenic compounds.
Kuehn, BM. 2007. Expert panels weigh bisphenol-A risks. Journal of the American Medical Association, October 3, 2007, Vol 298(13):1499-1500,1503.
Vandenberg LN, Hauser R, Marcus M, Olea N, Welshons WV. 2007. Human exposure to bisphenol A (BPA). Reproductive Toxicology 24(2):139-77. The abstract of this paper is available at http://www.ncbi.nlm.nih.gov/sites/entrez?db=pubmed&uid=17825522&cmd=showdetailview&indexed=google. (That entire URL must appear on one line in your browser.)
Prepared by David F. Parkhurst, October 18, 2007
Revised September 6, 2008