Bisphenol S (BPS) is a synthetic organic compound belonging to the bisphenol family. It is characterized by two hydroxyphenyl groups connected by a central sulfonyl group, which differentiates it from other bisphenols.
BPS is used in the manufacturing of plastics, resins, and other materials. It serves as a component in the production of polyethersulfone and certain epoxy resins.
The Rise of BPS as a BPA Alternative
Public and scientific concerns over the health effects of Bisphenol A (BPA) grew significantly, leading to widespread consumer demand for “BPA-free” products. This pressure prompted manufacturers to seek out substitutes for BPA in their production processes. The goal was to find a compound that could replicate BPA’s desirable properties, such as durability, stability, and heat resistance, which are important for plastics and epoxy resins.
Bisphenol S emerged as a primary replacement because of its structural similarity to BPA. Manufacturers saw it as a suitable alternative that would allow them to continue producing goods like polycarbonate plastics and can linings without major changes to their industrial methods. BPS could be integrated into existing manufacturing for items like plastic baby bottles and the linings of food cans, previously made with BPA.
Common Sources of BPS Exposure
Human exposure to Bisphenol S comes from a variety of everyday consumer products. One of the most prevalent sources is thermal paper, which is widely used for cash register receipts, event tickets, and labels. The BPS is used as a color developer in the heat-sensitive coating of the paper and can be absorbed through the skin upon handling.
Another significant route of exposure is through food and beverage packaging. BPS is used to make the epoxy resin linings of some metal food and drink cans, and the chemical can leach from this lining into the food or liquid.
Additionally, BPS is found in certain hard, clear plastics, some of which may be marketed as “BPA-free.” These can include reusable water bottles, food storage containers, and even some medical devices. The compound can also be present in indoor dust, which can be inhaled or ingested.
Health Implications of BPS
Initial assumptions that BPS was a safe substitute for BPA have been challenged by scientific research. Studies indicate that BPS is also an endocrine disruptor, meaning it can interfere with the body’s hormonal systems. Its chemical structure allows it to interact with hormone receptors in a manner similar to BPA, sometimes with comparable or even greater potency.
Research has linked BPS exposure to several adverse health outcomes. For instance, studies have shown it can impact reproductive health by potentially reducing the viability of eggs. It may also interfere with fetal development, as the compound can cross the placental barrier. Some studies have connected higher levels of BPS in children to insulin resistance and irregularities in vascular function.
Laboratory studies using cell models have demonstrated that BPS can promote the proliferation of certain types of breast cancer cells. Because the shared endocrine-disrupting properties mean that replacing one with the other does not eliminate the risk, regulatory bodies like the European Chemicals Agency have classified BPS as a substance of very high concern. The evidence suggests that “BPA-free” products containing BPS may not be any safer.
Reducing Personal Exposure
Taking steps to minimize contact with BPS can help lower personal exposure levels. A primary strategy involves being mindful of thermal paper receipts. You can decline paper receipts whenever possible, opting instead for electronic versions sent via email or text. After handling any thermal paper, it is advisable to wash your hands thoroughly, especially before preparing or eating food.
Modifying food and beverage storage habits is another effective measure. Prioritize using containers made from glass, stainless steel, or wood for storing food and drinks, particularly when they are hot. Reducing reliance on canned foods by choosing fresh or frozen alternatives can also decrease exposure. When purchasing plastic products, look for alternatives to polycarbonate, even if they are labeled “BPA-free,” as they may contain BPS or other bisphenols. While it is challenging to avoid all sources of BPS, these practical adjustments can collectively reduce your overall exposure.