Breaking new research indicates that manufacturers throughout the world who were using the toxic hormone-disrupting chemical bisphenol A (BPA), may have simply switched to an equally toxic analogue in the same bisphenol chemical class known as bisphenol S (BPS), to evade regulatory oversight and trick consumers with their misleading "BPA-FREE!" labels....
If you are already sensitive to the highly concerning issue of toxic chemicals in everyday consumer products, you've probably noticed these "BPA-Free" labels popping up everywhere. Bisphenol A (BPA), of course, is a chemical capable of disrupting our hormones, and is especially problematic in pregnancy, infancy and childhood -- times of greatest susceptibility to the adverse effects of environmental exposures.
Now that consumers are refusing to buy BPA-containing containers, manufacturers have had no choice but to oblige with seemingly bisphenol-free alternatives. Ironically, BPA is used to make Sippy Cups (and polycarbonate) shatterproof, and therefore "safer." But, instead of manufacturers actually removing the danger in BPA-free labeled products, many are capitalizing on this marketing opportunity by removing only the perception of danger, opting to substitute BPA for equally toxic members of the bisphenol chemical class.
An Alphabetic Soup of Toxic Bisphenols In Consumer Goods
While BPA has received the most negative attention, often being labeled as "bisphenol" for short, the bisphenols are such a broad chemical class that they are identified pseudo-alphabetically, spanning letters A-Z:
- Bisphenol A
- Bisphenol AB
- Bisphenol AF
- Bisphenol B
- Bisphenol BP
- Bisphenol C
- Bisphenol E
- Bisphenol F
- Bisphenol G
- Bisphenol M
- Bisphenol S
- Bisphenol P
- Bisphenol PH
- Bisphenol TMC
- Bisphenol Z
Figure: Bisphenol A
Bisphenol A has become the primary focus of consumer advocates for several reasons:
1) It is the most extensively research bisphenol, with at least 40 potential adverse health effects identified in the biomedical literature thus far.
2) Canada became the first country to officially declare BPA a "toxic substance" in September 2010
3) It has the highest production volume and use in consumer goods, with 2.2 million tons consumed globally in 2009.
Primary routes of exposure include:
- PVC water lines
- Canned Goods
- Thermal Receipt Paper
- All World Paper Currency
- Dental Sealants
Despite industry spokespersons and industry-funded scientists claiming BPA does not possess estrogenic properties of any biological significance, it was first acknowledged and used as an artificial estrogen in the early 1930’s, where it was used both to fatten poultry and cattle, as well as a form of estrogen replacement therapy in women in the mid-1930’s. Only later, in the 1940’s, did Bayer and General Electric use BPA to harden polycarbonate plastics and make epoxy resin, the latter of which is still used to line nearly the entire world’s supply of food and beverage containers. Only Japanese industries, which responded to consumer concern about the toxic effects of BPA between 1998-2003, voluntarily reduced BPA in favor of safer alternatives.
Figure: Bisphenol S
In the United States and abroad, in response to growing consumer concern over the safety of BPA, manufacturers have been rapidly substituting Bisphenol S (and possibly other bisphenol analogues) in its place.
How do we know this? After all, manufacturers are not required to list bisphenols explicitly on the labels of the consumer products within which they are used. Two new studies reveal that Bisphenol S (BPS) has become as dominant as BPA in manufacturing paper products we come into contact daily, as well as in terms of measurable human exposure....
New Research Proves Bisphenol A Is Secretly Being Replaced By Bisphenol S
First, a study published last week in the journal Environmental Science & Technology found BPS in thermal paper from stores in the US, Japan, South Korea and Vietnam, at concentrations similar to earlier reports of BPA. Concentrations were found as high as 22 mg per gram of paper -- two orders of magnitude higher concentrations than are considered biologically significant. BPS was also found in 87 percent of the paper currency assayed from 21 countries, indicating it is being utilized on a truly global scale.
The same week the same journal published another study titled, "Bisphenol S in Urine from the United States and Seven Asian Countries: Occurrence and Human Exposures," revealing for the first time that Bisphenol S concentrations in urine from the citizens of 8 countries were within the same concentration ranges as Bisphenol A levels reported by the same research group in the year before.
Is Bisphenol S Safer Because We Know Less About It?
Despite the industry-wide move away from BPA towards BPS, they both exhibit similar estrogen-like properties. A 2005 study performed by a Japanese research group found that BPS was only a slightly weaker estrogen than BPA. But, as the Environmental Health News reported in 2010:
They [Japanese researchers] tested the effects on human cells and found that bisphenol S was slightly less potent than BPA, but not by much: bisphenol S was active at 1.1 micromolar concentration, BPA at 0.63 micromolar. One micromolar is roughly equivalent to a packet of sugar in 3,000 gallons of water.
A growing body of additional research now indicates that Bisphenol S is both estrogenic and uterotrophic (increasing the weight of the uterus), with clearly carcinogenic potential.    
A 2012 study published in the journal Toxicology In Vitro discussed the industry-wide shift from using BPA in plastic baby bottles to BPS after the European Commission imposed a restriction on BPA use in 2011, as a direct result of scientific concerns over its estrogenic properties. The researchers found that "By using two highly standardised transactivation assays, we could demonstrate that the estrogenic activity of Bisphenol A and Bisphenol S is of a comparable potency."
The problem is that BPS is less well-known and researched than BPA for its potential adverse effects, and while regulators wait for manufacturers who promote their products with "BPA-Free!" stickers at the same moment that they infuse them with BPS to voluntarily reformulate, there is evidence now that BPS may actually have worse effects to environmental and human health, alike..
One of the main concerns is that BPS is significantly less biodegradable than BPA. According to a study published in the International Journal of Environmental Research & Public Health in 2009, BPS "… is not amenable to biodegradation and might be persistent and become an ecological burden." Another study published in the journal Environmental Toxicology & Pharmacology in 2005 found that BPS is "…more heat-stable and photo-resistant than bisphenol A."
BPS' relative inability to biodegrade indicates: 1) once it is absorbed into the human body, it may accumulate there for longer periods of time. 2) it is more likely to persist in the environment, making external exposures to it, and its many metabolites, much more likely than the faster degrading BPA. In other words, its potential to do harm will worsen along the axis of time, not lessen, which is a common argument made for the purported "safety" of BPA.
Are We A Population of Guinea Pigs Without The Precautionary Principle?
Recently, it was discovered that synthetic estrogens are leaching into our bodies from consumer products (e.g. parabens) and are now eclipsing natural human estrogens. A paraben ester was found at 1 million times higher concentrations than natural estrogen levels in the breast tissue of mastectomy patients. After several generations of "better living through chemistry," we are discovering that we have poisoned ourselves and our environment (can we really separate them any longer?) into profound and possibly irrevocable disfigurement. What is needed now more than ever is a paradigm shift in how we regulate our exposure to chemicals, and the industries that produce them virtually unrestricted.
Perhaps we must begin asking ourselves: What would the chemical and drug industries do without the twin disciplines of toxicology and pharmacology? The former provides ample justification for continually exposing us to "an acceptable level of harm" from the chemicals it secretes, and the latter convinces us just how we can’t live without "therapeutic" chemicals, e.g. pharmaceuticals.
Until we demand the implementation of the precautionary principle in this country, and abroad, nothing will change ... other than, increasingly, our very biological and genetic integrity, for the worse.
 Erler, C. & Novak, J. Bisphenol A Exposure: Human Risk and Health Policy. Journal of Pediatric Nursing. 2010. Volume 25:400-407. Accessed online March 1, 2012.
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