Just like the controversial compound it's designed to replace, a chemical used in cash register receipts and other consumer products messes with hormones, according to research published today.

The study by University of Texas scientists is the first to link low concentrations of bisphenol S (BPS)  – a bisphenol A (BPA) alternative  – to disruption of estrogen, spurring concern that it might harm human health.

Researchers exposed rat cells to levels of BPS that are within the range people are exposed to. And, just like BPA, the compound interfered with how cells respond to natural estrogen, which is vital for reproduction and other functions.

Previous studies already have shown BPS mimics estrogen, but the new study advances that by showing it can alter the hormone at low doses people are exposed to.

“People automatically think low doses do less than high doses,” said Cheryl Watson, a University of Texas biochemistry professor and lead author of the study published in Environmental Health Perspectives. “But both natural hormones and unnatural ones like [BPS] can have effects at surprisingly low doses.”

Laura Vandenberg, a postdoctoral fellow at Tufts University who studies BPA, said one limitation of the research was that it used rat cells, but she was quick to point out the method is “extremely informative about predictions for a whole animal.”

The study “ is a great first research step on BPS and, in my opinion, should be sufficient to say this is an estrogen and we don’t want it in our bodies,” Vandenberg said.

As its name would suggest, BPS has a similar structure to BPA, which has been used since the 1950s for a variety of purposes, including the manufacture of polycarbonate plastics.

In the past several years, BPS has replaced BPA in the printing of thermal paper used for cash register receipts. Every thermal receipt tested in a study published last year contained BPS.

Bill Van Den Brandt, a manager at Wisconsin-based Appleton Papers, said company representatives couldn’t comment on the Watson study because they had not fully reviewed it yet. He added that they “welcome ongoing scientific review of BPS and other potential BPA substitutes.”

The largest manufacturer of thermal papers in North America, Appleton switched to BPS after it stopped using BPA in 2006 due to health concerns.

Nearly everyone worldwide is exposed to BPS. Eighty-one percent of urine samples from eight different countries contained traces of it, according to a study published last year. In comparison, about 93 percent of Americans have BPA in their urine.

Watson said she is worried that BPS is becoming more widespread without proper testing for health impacts.

“I think we should all stop and be very cautious about just accepting this as a substitute for BPA,” Watson said. “And not just BPS. We should question the whole process about how we introduce chemicals into the marketplace without properly testing them first.”

In addition to thermal papers, BPS is used in some hard plastics, Vandenberg said.

“A lot of consumer products say BPA-free, but they don’t say BPS, a similar compound, replaced it,” she said. She said BPS is less likely to leach into food and beverages because the bonds that hold the compounds in the plastic are stronger than those in BPA products.

A lesser-known use for thermal paper is for ultrasound and other medical machine printouts. According to a 2012 report by the EPA, these BPA-free printouts largely contain BPS.

4 Comments

1. 1. RSchmidt in reply to Vendicar Decarian 01:47 PM 1/17/13

   @Vendicar Decarian, wow you are a real nutter.

   Reply | Report Abuse | Link to this

2. 2. greenhome123 04:57 PM 1/17/13

   i think Vendican Decarian was being sarcastic. Anyways, i'm going to start asking for no receipt from now on. I believe that the EPA should ban both BPA and BPS receipts. We have the technology to send customer receipts via text message or email. It would save stores money to send receipts that way as well since they wouldn't have to buy the receipt paper.

   Reply | Report Abuse | Link to this

3. 3. mudphud 01:37 PM 1/22/13

   This is one of those controversies that drives me nuts. Does BPA mimic estrogen in cell culture? Yes. Does it affect rats? Yes, they have a circulation system between their gut and liver that greatly prolongs it's half life after exposure. Does it affect humans? Probably not much, human livers rapidly modify BPA with glucuronide so that free BPA is almost undetectable, and all of it is in the urine tihin 6 hours. Does BPA-glucuroniode have ANY detectable estrogen activity? NO. Sometimes cell culture and rats do not translate to human risks. A lot of times it does, some times it misses things, but not in this case. But what about babies? Their livers don't detoxify like adults! True, but only for certain pathways- BPA gets eliminated immediately. Studies looking at levels in human serum that have shown high levels if free BPA would require huge exposures to BPA, and no such sources have been identified, leading to the conclusion that there is either a contamination (BPA is all over the place in lab equipment) or the inactive form breaking down in samples over time to leave free BPA. Overall, it probably deserves more study but it seems like an overreaction.
   
   I don't have access to the BPS article, but the abstract say BPS in urine thay measured is a sum of BPS and BPS-glucuronide. Since they don't separate it, I would suspect the inactive conjugated form is most of it, which is far less sensational. There are plenty of things we know are harmful to us in the environment in measurable ways, it seems foolish to ban substances we can't even measure human toxicities from that will cause to just use less studied compounds as replacements.

   Reply | Report Abuse | Link to this

4. 4. bucketofsquid in reply to mudphud 12:49 PM 2/1/13

   This is why companies should be forced to prove safety before being allowed to bring anything to market. The pattern of waiting until millions are harmed and dozens or even hundreds are killed is just not acceptable.

   Reply | Report Abuse | Link to this