As we reported on back in June of last year, in an exposé titled, Consumer Alert: BPA-Free Goods Still Contain Toxin Bisphenol, the petrochemical bisphenol A (BPA), a ubiquitous ingredient in thousands of consumer products and which has been linked to a wide range of serious adverse health effects,[i] has been removed by many ostensibly scrupulous manufacturers in favor of another equally toxic analog in the same chemical class, known as bisphenol S (BPS). This has enabled manufacturers of products as varied as thermal printer receipts to sippy cups to advertise their products as "BPA-free," while still exposing consumers to potentially harmful, and less regulated chemicals.
BPS is actually not only within the same range of toxicity of BPA, but is slower to degrade, and therefore will be more likely to remain a persistent toxin and environmental pollutant.[ii] It has already been found to be present in the urine of 81% of those tested from the United States and seven Asian countries.[iii]
Now, new concern is being raised by a study published this month in the journal Environmental Health Perspectives showing that BPS has estrogenic activity comparable to estradiol, the most potent and therefore concerning human estrogen, and is even capable of enhancing estradiol-mediated cell signaling activity. These actions indicate it has great potential to disrupt normal endocrine processes. The study also found that BPS is capable of inducing cell death (apoptosis), as well as interfere with cellular prolactin (PRL) secretion. This latter effect has a broad range of indications, as the prolactin hormone regulates hundreds of biological functions, including metabolism, reproduction and lactation.[iv]
Taken together, the study authors concluded:
BPS, once considered a safe substitute for BPA, disrupts membrane-initiated E2-induced cell signaling, leading to altered cell proliferation, cell death, and PRL release.
Global Chemical Sleight-of-Hand: BPS Replaces BPA
In many ways, the sleight-of-hand substitution of Bisphenol S for Bisphenol A, is just business as normal. Pharmaceutical companies, for instance, will often begin to phase out a drug when after years of causing side effects and even deaths it begins to lose its viability as a profit center because of accumulating lawsuits and adverse post-marketing surveillance research, as well as the impending expiration of its patent exclusivity. So, they simply alter the synthetic drug an atom or two, and reapply for a "new and improved" drug approval – even when, essentially, less is known about its toxicity; until, that is, the end users (a living guinea pig) experience convincing bodily evidence that it does more harm than good.
Sadly, chemicals like bisphenols receive far less regulatory oversight than pharmaceuticals, despite the fact that exposure to pharmacologically active chemicals in everyday consumer products can be much more widespread.
The extent to which manufacturers have replaced BPA with BPS is unknown, but a 2012 study published in the journal Environmental Science and Technology titled "Bisphenol S, a New Bisphenol Analogue, in Paper Products and Currency Bills and Its Association with Bisphenol A Residues," indicates the shift is global, and therefore likely internally coordinated by the chemical industry:
As the evidence of the toxic effects of bisphenol A (BPA) grows, its application in commercial products is gradually being replaced with other related compounds, such as bisphenol S (BPS). Nevertheless, very little is known about the occurrence of BPS in the environment. In this study, BPS was analyzed in 16 types of paper and paper products (n = 268), including thermal receipts, paper currencies, flyers, magazines, newspapers, food contact papers, airplane luggage tags, printing paper, kitchen rolls (i.e., paper towels), and toilet paper. All thermal receipt paper samples (n = 111) contained BPS at concentrations ranging from 0.0000138 to 22.0 mg/g (geometric mean: 0.181 mg/g). The overall mean concentrations of BPS in thermal receipt papers were similar to the concentrations reported earlier for BPA in the same set of samples. A significant negative correlation existed between BPS and BPA concentrations in thermal receipt paper samples (r = -0.55, p<0.0001). BPS was detected in 87% of currency bill samples (n = 52) from 21 countries, at concentrations ranging from below the limit of quantification (LOQ) to 6.26μg/g (geometric mean: 0.029 μg/g). BPS also was found in 14 other paper product types (n = 105), at concentrations ranging from88%). To our knowledge, this is the first report on the occurrence of BPS in paper products and currency bills.