BPA in cash register receipts is easily transferred to skin.

Nov 02, 2010

Biedermann, S, P Tschudin and K Grob. 2010. Transfer of bisphenol A from thermal printer paper to the skin. Analytical and Bioanalytical Chemistry http://dx.doi.10.1007/s00216-010-3936-9.

Synopsis by Emily Barrett

New research finds that Bisphenol A can rub off on hands through contact with sales receipts, although some scientists think that the amount of chemical transferred may be too low to cause alarm.

New research finds bisphenol A (BPA) in the thermal printer paper commonly used to make sales receipts. The environmental chemical has received a great deal of attention in recent years, in part because of public outcry for its removal from baby bottles. Other sources of BPA, though, have received less attention until now.

Swiss researchers analyzed BPA levels in cash register receipts and then looked at the amount of the chemical that was transferred to the skin after handling. They found that the amount of BPA on the skin depended on conditions of handling, such as whether the hands were greasy or clean. The researchers estimated that even under worst case scenarios with extensive handling of BPA-laden receipts, typical exposure levels are likely to be below limits currently considered dangerous.

BPA has been linked to a wide range of negative health effects, ranging from aggressive behavior to obesity. Despite concern about these potential health consequences, exposure to the chemical is widespread, with 95 percent of Americans showing measureable levels in their blood. Until the Environmental Working Group recently published a popular report, however, there was little public awareness that BPA – which is typically associated with plastics – is also found in some types of paper used to make cash register receipts.

In the newly released study, nearly all of the thermal printing papers sampled – including 9 of 10 sales receipts – contained measureable amounts of BPA. Although the amount in the individual receipts varied, it was typically about 1 percent of the chemical make-up of the receipt. This represents an amount up to 1,000 times greater than what is likely to leach from a baby bottle into its contents.

The researchers then measured the amount of BPA on the hands after receipts were handled under various conditions. Not surprisingly, 10 times as much BPA was transferred from contact with the printed side of the receipts as compared to the unprinted side. Transfer was particularly high, moreover, when fingers were wet or greasy, as opposed to clean and dry. The scientists hypothesize that using lotions may promote even greater transfer and absorption of BPA.

Although most of the BPA seemed to stay on the surface of the hands, the longer it was left there, the more it migrated beneath the skin. After two hours of exposure, only about 73 percent of the initial amount of BPA could be retrieved from the surface of the skin, suggesting that the remainder had been absorbed deeper into the body.

Interestingly, repeated contact with the paper did not seem to increase the amount of BPA found on the fingers, leading the researchers to suggest that even individuals who handle large numbers of receipts, such as sales clerks, are unlikely to pick up extreme quantities of BPA from the receipts. The researchers estimated that even after many hours of repeated exposure without handwashing, exposure is unlikely to go above 71 micrograms (μg) per day, a figure less than one-eighth that believed to be safe under current European standards.

What’s needed next are studies that move beyond the BPA transferred to the surface of the skin to instead look at the actual amounts of the environmental chemical found in the body after handling receipts. In order to more accurately assess the true risks, the next wave of studies should also address BPA exposure through receipts in natural settings, rather than just in closely controlled experimental settings.