A study published today in the journal PLOS One suggests that people who frequently handle thermal cash register paper are exposed to high levels of bisphenol A (BPA), a chemical widely used to coat till receipts.
Researchers from the University of Missouri and the Universite de Toulouse set up an experiment where 10 individuals used hand sanitiser, touched a cash register receipts and then ate fried chips with their hands. They found that the individuals had a rapid increase of BPA in their blood, and that women had more of the chemical than men.
However, the study has been criticised for not representing real scenarios and for not recognising that the levels are too low to induce measurable biological effects.
Our colleagues at the Australian and UK SMC collected the following expert commentary. Feel free to use these quotes in your reporting. If you would like to contact a New Zealand expert, please contact the SMC (04 499 5476; smc@sciencemediacentre.co.nz).
Dr Ian Musgrave, Senior Lecturer in the Faculty of Medicine at the University of Adelaide, comments:
“Bisphenol A (BPA) is a weakly estrogenic chemical used in a number of different commercial applications, from hard plastics to thermal printer paper. People are typically exposed to levels of BPA well below those with a biological effect.
The current paper “Holding Thermal Receipt Paper and Eating Food after Using Hand Sanitizer Results in High Serum Bioactive and Urine Total Levels of Bisphenol A (BPA)” looks at whether thermal receipt paper could be a significant source of BPA exposure for humans. The conditions used in this experiment are quite unlike any realistic use of thermal paper. The subjects held thermal paper in hands wet with hand sanitisers that had high skin penetration for four minutes, then immediately handled and ate food. Even under these extreme conditions, the BPA levels in the subjects blood all remained well under levels shown to have a biological effect, and was quickly eliminated from the blood. Subjects with dry hands who held the receipts for the same long time showed no change in blood or urine BPA.
This study shows that for the majority of the population handling thermal paper is not a significant source of BPA. Cashiers who wish to be cautious should not handle thermal paper when their hands are wet with skin penetrating hand sanitisers, and follow standard public health advice to wash their hands before eating food.”
Dr Oliver Jones, Lecturer in Analytical Chemistry in the School of Applied Sciences at RMIT University Melbourne, comments:
“This paper presents an interesting study on a potential, new exposure pathway for BPA; namely co-exposure with skin sanitisers. The authors seem to have carried out the experiments sensibly and taken care to minimise potential sources of error in their work. However, while I do not doubt the results of the study as it happened in the lab, this exposure pathway seems to be limited to occasions when one handles a freshly printed receipt immediately after having used an alcohol based hand sanitiser; something I have never personally seen or experienced.
I also do not think that the authors have provided anywhere near enough evidence for their assertion that BPA, or similar chemicals, in thermal paper pose a threat to human health. The authors only list two papers to back up this claim; both of which are reviews and neither of which reached a firm conclusion on the issue. One author of the present study was also a co-author of one of the reviews and this same author has a reputation of being extremely anti-BPA, which makes one wonder if the present work was conducted with a truly open mind. To the best of my knowledge, nobody has yet conclusively proved that BPA is toxic at any realistic dose, or that it has ever harmed anybody, despite it being in use since the 1950s. So, while I think that the present work is interesting, I do not think the results are a cause for concern for the general public”.
Professor Ian Rae, Honorary Professorial Fellow at the University of Melbourne and Former President of the Royal Australian Chemical Institute, comments:
“It should not be beyond the capability of the producers to find another mild acid catalyst to replace BPA in thermal receipt paper. They are not trying hard enough!
The demonstration that more BPA is transferred to wet hands is hardly surprising, as is ingestion of BPA transferred from paper-to-hands-to-French fries. A study (not referenced in the present article) of a range of paper products three years ago found that thermal receipts were the main source of BPA and that average users would absorb 17.5 nanograms/day through the skin, rather less than found on wet and dry hands in the present work. Much more than this is absorbed from the traces of BPA in food in a normal diet.
Health effects are still a matter of contention and investigation.”
Dr Anna Callan, Lecturer in the School of Medical Sciences and Faculty of Health, Engineering and Science at Edith Cowan University Western Australia, comments:
“The chemical Bisphenol A (BPA) appears in many products that we use regularly. Studies measuring metabolites of BPA in urine have revealed that almost everyone tested is exposed to BPA, which is of concern as it is able to mimic oestrogen and has been implicated in a range of adverse health effects. Most people are aware that BPA is found in polycarbonate refillable water bottle and baby bottles and, in response to public demand, many manufacturers now offer products that are BPA free. It is less commonly known that BPA is also found in other places such as the lining of tin cans and on the surface of thermal paper used in till receipts.
Previous studies have shown that cashiers have higher concentrations of BPA in their urine than the general public. This study has shown that handling of thermal paper may be a significant source of BPA exposure in the general public, particularly when receipts are handled after the use of hand sanitiser.
The study looked at direct transdermal (through the skin) exposure as well as the transfer of BPA onto food (in this case french fries) that were then eaten by participants. The scenario of the participants handling till receipts and then eating without washing their hands was designed to mimic real life situations e.g. in some fast food restaurants. The study was limited to a small number of participants, but it was quite comprehensive and provides an important starting point for the investigation of the role of skin contact in BPA exposure in the community. It is really important that we understand not only the potential health effects of exposure to chemicals such as BPA, but also how people are exposed to them. Understanding the sources of exposure allows us to look at ways in which people could alter their behaviour in order to reduce their exposure, but also provides evidence to regulatory agencies and manufacturers so that they can consider changes to regulations and manufacturing processes in order to better protect the public.”
Prof Richard Sharpe, Group Leader of the Male Reproductive Health Research Team, University of Edinburgh, comments:
“Till receipts frequently use bisphenol A in the ink. This study has investigated how much bisphenol A may be absorbed via the hands when handling such receipts, especially in a ‘fast food’ restaurant situation, by devising experiments involving humans handling till receipts with and without use of hand wipes (sanitizers) and eating chips. The authors’ conclusion is that handling of till receipts, especially after using hand wipes, can result in significant transfer of bisphenol A through the skin and into the bloodstream.
“Whilst the study appears in general to have been well conducted, some aspects appear improbable – handling a receipt for 4 minutes, for instance, seems unrealistically long. These seem deliberately designed to maximize exposure, rather than to reflect the real world.
“My main concern, however, is that the measurements of active vs inactive bisphenol A in the blood of the people in the study who handled receipts appears dramatically different to those reported in most other scientific experiments, which indicate that over 95% of bisphenol A in blood is biologically inactive. This is difficult to explain, but might indicate contamination of blood samples with environmental bisphenol A in this new study.”