FTIR analysis
Based on the FTIR spectra of the surfaces of 167 receipts from 148 businesses, we sorted results into the following categories: BPA, BPS, Pergafast 201, uncoated, and inconclusive. Table 3 and Table 4 sort results by business category and sector, respectively.
Of the 167 receipts, BPS was the most prevalent (75% of receipts) followed by BPA (18%), inconclusive, (3%), no coating (2%), and Pergafast 201 (1%). Pergafast 201 was detected only in the two receipts collected from two Best Buy stores.
We compared receipts from the retail sector (apparel/jewelry, books/office, department/big box, drugstore, gas station/convenience, grocery, pets, resale, toy stores ) versus the service sector (automotive, bank, entertainment, library, post office, printing and electronics, restaurants/bars, salon, travel). BPS was the most common developer chemical in both sectors (85% of retail and 68% of service sector receipts). Table 4 shows that BPA was more prevalent among the service sector receipts (26% of service sector receipts versus 8% of retail receipts). Many of the service sector receipts were restaurants.
Four receipts were uncoated; in other words, they appear to be regular paper, not thermal paper. These receipts were from three business: Brooks Lumber, Village Hardware, and two different Culver's restaurant locations.
Other chemicals detected
In addition to BPA, BPS, and Pergafast 201, we identified the chemical diphenyl sulfone in many of the BPS-containing receipts. Diphenyl sulfone is used as a sensitizer in thermal paper and was recently quantified in receipts from Germany (Eckart 2017).
Many receipts also contained characteristic infrared bands of calcium carbonate, a common filler in plastics and coatings.
Table 3: Developer chemicals detected by FTIR in paper receipts sorted by business category.
| Business Category | Number of Samples | BPA | BPS | Pergafast 201 | Inconclusive | No Coating |
|---|---|---|---|---|---|---|
| Apparel/Jewelry | 7 | 1 | 6 | 0 | 0 | 0 |
| Automotive Service | 2 | 0 | 1 | 0 | 1 | 0 |
| Bank | 5 | 0 | 5 | 0 | 0 | 0 |
| Books/ Office | 6 | 0 | 6 | 0 | 0 | 0 |
| Department/ Big Box | 20 | 0 | 17 | 2 | 1 | 0 |
| Drugstore | 5 | 0 | 5 | 0 | 0 | 0 |
| Entertainment | 8 | 2 | 6 | 0 | 0 | 0 |
| Gas Station/ Convenience | 5 | 3 | 2 | 0 | 0 | 0 |
| Grocery | 16 | 3 | 13 | 0 | 0 | 0 |
| Library | 3 | 3 | 0 | 0 | 0 | 0 |
| Other | 8 | 0 | 6 | 0 | 0 | 2 |
| Pets | 4 | 0 | 4 | 0 | 0 | 0 |
| Post Office | 2 | 0 | 2 | 0 | 0 | 0 |
| Printing/ Electronics Service | 5 | 1 | 4 | 0 | 0 | 0 |
| Resale Store | 2 | 0 | 2 | 0 | 0 | 0 |
| Restaurant/ Bar | 62 | 16 | 43 | 0 | 1 | 2 |
| Salon | 2 | 1 | 1 | 0 | 0 | 0 |
| Toys | 3 | 0 | 3 | 0 | 0 | 0 |
| Travel (Bus, Air, Parking) | 2 | 0 | 0 | 0 | 2 | 0 |
| Total | 167 | 30 | 126 | 2 | 5 | 4 |
Table 4: Receipt results by sector
| Sector | Number of Samples | BPA | BPS | Pergafast | Inconclusive | No Coating |
|---|---|---|---|---|---|---|
| Retail | 73 | 6 (8%) | 62 (85%) | 2 (3%) | 1 (1%) | 2 (3%) |
| Service | 94 | 24 (26%) | 64 (68%) | 0 (0%) | 4 (4%) | 2 (2%) |
| Total | 167 | 30 (18%) | 126 (75%) | 2 (1%) | 5 (3%) | 4 (2%) |
Gas chromatography/mass spectrometry (GC/MS) analysis
Four paper receipts were analyzed by GC/MS. Three were tested for both BPA and BPS and one, a sample of EKG paper, was tested only for BPA. Table 5 lists the results. The first two “Measurement” columns give BPA and BPS in units of parts per million (ppm), which is the same as ug/g. The next two columns give the results based on surface area of the paper: micrograms per square centimeter.
GC/MS analysis corroborated our FTIR results. The sample we had identified by FTIR as containing BPS (Von Maur) was found to have a BPS concentration three orders of magnitude higher than the other samples: 71,000 ppm BPS at Von Maur store compared to 27 and 73 ppm in the other receipts.
Similarly, the sample we had identified by FTIR as containing BPA (EKG paper) was found to have a BPA concentration two orders of magnitude higher than the other samples: 14,500 ppm BPA in the EKG paper compared to 24 and 95 ppm in the others.
Our FTIR analysis determined that the Culver’s receipt was uncoated and the Delta receipt was coated with an inconclusive developer, neither BPA nor BPS. The GC/MS analysis accordingly found low levels of BPA and BPS in these receipts, much too low to be used as a developer in the thermal coating.
We posit that the relatively low levels of BPA (3, 24, and 95 ppm) and BPS (27 and 73 ppm) found by GC/MS in receipts not expected to contain these developers reflect the ease with which the developer chemicals are transferred from one surface to another (Liao and Kannon, 2011b). The receipts were collected as convenience samples from consumers, who typically handled them with bare hands that may have touched other receipts and in some cases temporarily carried them in a bag or pocket. Consumers then placed the receipts in paper envelopes with printed sides folded in.
Trace amounts of BPA and BPS could also come from recycled paper used to manufacture the thermal paper (Liao and Kannon, 2011b).
Table 5. Gas chromatography/mass spectrometry (GC/MS) results for four paper receipt samples
| Measurement by GC/MS (detection limit 1 ug/g) | ||||||
|---|---|---|---|---|---|---|
| Name | Our Result from FTIR | BPA, ppm | BPS, ppm | BPA, ug/cm2 | BPS, ug/cm2 | |
| Culver's Receipt | Not coated | 3 | 27 | 0.02 | 0.16 | |
| Von Maur Receipt | BPS | 95 | 71,000 | 0.42 | 311 | |
| Delta Receipt | Inconclusive | 24 | 73 | 0.18 | 0.56 | |
| EKG paper* | BPA | 14,500 | not tested | 78.6 | not tested | |
* The EKG paper sample was not part of the citizen receipt collection and is not technically a receipt so, while we used it to validate our BPA FTIR determination, we have not included it in Tables 3 and 4.
Comparison with previous studies on BPA and BPS in receipt paper
Table 6 compiles our GC/MS results from six prior studies by other researchers. Our quantification of BPA in an EKG paper sample--14,500 ppm--is similar to the upper range of results from receipts from multiple other countries.
The concentration of BPS we measured in a Von Maur store receipt is higher than that in receipts from recently published studies. We found 71,000 ppm BPS, whereas receipts from Italy and Japan had up to 3,600 and 6,100 ppm BPS, respectively, and U.S. receipts in a 2012 study had up to 22,000 ppm BPS (Liao 2012). The reason for the variation is unknown.
For an in-depth review of research on new developer chemicals in thermal receipts and the implications for human exposure, see Bjornsdottir 2017.
Thermal paper tickets
In addition to the 208 receipts analyzed in this work, a number of paper tickets for theater, concerts, parking, train, plane, and bus were collected. These tickets were thicker and stiffer than other receipts such as those from stores and restaurants. The tickets showed a more complex mixture of coating ingredients and the developer was difficult to identify. Since many of the tickets had an inconclusive result, we have excluded the thicker paper tickets from the present analysis and hope to identify them in a future study.
Table 6. Comparison of receipt BPA and BPS measurements from multiple studies worldwide.
| Range measured in receipts, ug/g (ppm) | ||||
|---|---|---|---|---|
| Study | Receipts from: | BPA | BPS | |
| present work, 2017 | US, mostly Michigan (n=4) | 3-14,500 | 27-71,000 | |
| Russo et al. 2017 | Italy (n=50) | < LOQ-15,373 | LOQ-3,580 | |
| Lu et al. 2013 | China (n=42) | 2,580-14,700 | na | |
| Liao et al. 2012 | Japan (n=6) | na | .55-6,130 | |
| New York (n=81) | na | .014-22,000 | ||
| Various US cities (n=10) | na | 1-12,000 | ||
| Korea (n=11) | na | .09-11 | ||
| Vietnam (n=3) | na | .11-.56 | ||
| Geens et al. 2012 | Belgium (n=44) | .0044-21,000 | na | |
| Liao & Kannan 2011b | US (n=83) | 4.8-13,900 | na | |
| Korea (n=11) | 16-9,880 | na | ||
| Vietnam (n=3) | 6,150-6,530 | na | ||
| Japan* (n=6) | < LOQ | na | ||
| Mendum et al. 2010 | Boston (n=10) | 3,000-17,000 | na | |
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na=not analyzed
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LOQ=limit of quantification
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*Japan banned BPA from thermal receipt paper in 2001
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What can businesses do?
We recommend businesses with thermal receipt systems switch to less hazardous, drop-in replacement papers. On option is thermal paper with a phenol-free developer such as Pergafast 201 or one of the others detailed in EPA’s 2014 report. That report gives screening-level toxicological hazard assessments of each developer. Pergafast 201 presents some developmental and reproductive hazards, although is expected to be poorly absorbed through the skin, in contrast to BPA and BPS. In another research report, Pergafast 201 and a developer called D8 were found using a cell assay to have no hormone effect (Goldinger 2015).
A potentially superior alternative is a new thermal paper from Dow called BLUE 4EST™ Thermal Paper (Dow, 2017). According to the creators of this paper, it is not only phenol-free but uses a polymeric coating that does not come off like BPA and BPS and is approved for food contact.
We also recommend businesses use electronic receipts and offer consumers the option of skipping the paper receipt.
Conclusion
Our study suggests that BPS has replaced BPA to a large extent in U.S. thermal paper receipts, although BPA remains fairly common (75% BPS versus 18% BPA). A small number of businesses are using alternative, non-phenol developers or uncoated paper receipts.
Because receipts with freely available BPS and BPA are so ubiquitous, they are primary contributors to human exposure to these hormone-disrupting chemicals. We are particularly concerned about the effects of repeated, daily BPS and BPA exposure on young children, pregnant women, and workers who handle thermal paper.
Cashiers, waiters, bank tellers and many other employees handle as many as 30 receipts per hour. After a work shift, their urinary and blood levels of BPA and BPS are significantly higher than the general population. These chemicals easily transfer from receipt paper to hands and are rapidly absorbed into the blood through the skin. Combined with exposure from other sources like food packaging and adhesives, workers in particular can exceed tolerable intake values.
BPS was especially prevalent in the retail sector, comprising 85% of the 72 retail receipts, while 8% contained BPA. The service sector, including restaurants, appears to have moved toward BPS to a slightly lesser extent: Of the 61 service receipts, 68% had BPS and 26% had BPA.
One store, Best Buy, is using a non-phenol alternative we identified as likely Pergafast 201. Three other businesses--Culvers, Village Hardware, and Brooks Lumber, were found to be using receipt paper that contains no thermal coating.
We encourage all businesses to protect employees and customers by switching to a safer alternative and following the guidelines listed in the Recommendations section.