If you are aware of the dangers of BPA and are actively taking precautions to avoid exposure by selecting food and beverages packed in BPA-free packaging, you may still be vulnerable to the toxins associated with BPA, as well as the health hazards.

Bisphenol S (BPS), commonly used to replace hazardous bisphenol A (BPA) in household products, may be just as detrimental to cardiovascular health as BPA, according to the results of a new study, which were recently presented at a joint meeting held in Chicago by the Endocrine Society and the International Society of Endocrinology (ICE/ENDO 2014).

Since research has shown BPA to have many potentially harmful effects on humans, in recent years many manufacturers of hard plastics and other consumer products have chosen to switch from BPA to a chemically similar compound, BPS, marketing these products as BPA-free.

However, according to lead author of this study, Hong-Sheng Wang, from the University of Cincinnati, while some BPA-free products are free of bisphenols, "BPS is one of the substitutes used in BPA-free products. There is implied safety in BPA-free products. The thing is, the BPA analogs—and BPS is one of them—have not been tested for safety in humans."

BPA is a known hormone disrupter that can disrupt estrogen as well as other hormones, however, it is unclear whether BPS also interferes with hormones.

For this study -- which Wang refers to as an initial assessment of the effect of BPS on the primary cells and/or organs of mammals -- Wang and his colleagues tested a dose of BPS similar to that found in urine samples of humans in other studies, on the hearts of a sample of 50 rats.

When comparing the results of rats that were exposed to BPS to the control group that were not, female rats that were exposed to BPS exhibited a rapidly elevated heart rate, which led to abnormalities in heart rhythm under stress, which far exceeded that of the control group of rats that were not exposed to BPS. Electrocardiograms showed that for female rats, exposure to BPS resulted in additional heart beats and caused the heart to race. BPS did not reportedly have the same effect on the hearts of male rats.

To better understand the cause of these effects on the hearts of female rats, the research team looked at the muscle cells of affected rats. They discovered that BPS exposure led to abnormal cycling of calcium, which according to Wang, is a primary cause of an irregular heart beat. It is also very similar to the toxic effect that BPA has on the heart, as Wang and his team showed in an earlier study.

The researchers attempted to prevent the heart rhythm anomalies induced by BPS in the female rats by blocking an estrogen receptor. According to Wang, their results showed that "the BPA analog BPS is not necessarily free of endocrine-disrupting activity."

"Our findings call into question the safety of BPA-free products containing BPS," Wang concludes. "BPS and other BPA analogs need to be evaluated before further use by humans."

Bottled water is one consumer item that is packaged in plastic bottles that often contain BPA. These chemicals can potentially leach into the contents, especially when stored for long periods. To avoid long term exposure to Bisphenol toxins we advise drinking filtered water rather spring water supplied in plastic bottles.