Abstract

Thermal paper remains a major non-dietary and dietary source of bisphenol exposure despite national and international restrictions on bisphenol A (BPA). This study synthesizes findings from (i) a 2024 Delhi-based market surveillance analysis of thermal receipts following India’s BPA prohibition and (ii) a 2023 North American investigation demonstrating migration of bisphenol S (BPS) and alternative color developers from thermal food labels into fish. In India, 20 thermal receipts collected from multiple commercial sectors revealed widespread non-compliance: BPA was detected in 13 samples at concentrations up to 17,400 ppm, while nominally “BPA-free” papers often contained high BPS levels (up to 9,300 ppm). In North America, BPS was detected in 73% of thermal labels (mean: 66 μg/cm²; max: 193 μg/cm²), and migration studies showed BPS reaching 1140 ng/g wet weight in label-contact fish—far above the EU’s specific migration limit of 50 ng/g. Alternative developers such as D-8, D-90 and PF-201 also migrated at lower but measurable concentrations.

Across both data sets, evidence demonstrates that BPA substitution is frequently a regrettable substitution, shifting exposure from BPA to similarly endocrine-active bisphenols without reducing public health risk. The convergence of regulatory failures (India) and dietary exposure pathways (thermal labels) suggests an urgent need for stronger enforcement, comprehensive migration assessments, and development of non-bisphenolic thermal technologies. This combined analysis offers a coherent, evidence-based perspective for policymakers, retailers, manufacturers, and converters navigating the transition toward safer thermal paper systems.

Keywords

Thermal paper; bisphenol A; bisphenol S; D-8; D-90; PF-201; thermal label migration; India BIS compliance; endocrine disruptors; food packaging safety; BPA-free substitution; regulatory monitoring.

1. Introduction

Bisphenols are widely used in thermal paper coatings where they function as acidic developers in the heat-induced color reaction. BPA historically dominated this application due to its effectiveness and low cost, but mounting toxicological evidence—ranging from endocrine disruption to reproductive toxicity—prompted substantial policy interventions worldwide.

India adopted IS 17568:2021, a national specification prohibiting BPA in thermal paper. Similar measures were enacted earlier in Japan (BPA phase-out since 2001), the EU (0.02% w/w limit from 2020), South Korea (2021), and several U.S. states. As a result, BPS and alternative color developers (e.g., D-8, D-90, TGSA, PF-201) have become increasingly prominent.

However, these alternatives raise concerns:

• BPS shows estrogenic and anti-androgenic activity comparable to BPA.
• BPS persists longer in human blood and is more readily absorbed dermally.
• Alternative developers, though less studied, exhibit migration potential and incomplete toxicological profiles.

Research emphasis has traditionally focused on dermal exposure from handling receipts, but emerging evidence indicates that dietary exposure from thermal food labels applied on cling film may be a substantial, previously overlooked source.

This paper integrates two critical data pools:

1. 2024 Delhi receipt monitoring—evaluating compliance with India’s BPA ban and characterising BPS substitution trends.
2. 2023 McGill food-label migration study—documenting transfer of BPS and alternative developers into food.

Together, these datasets provide a panoramic view of bisphenol risks across regulatory, occupational, dietary, and environmental dimensions.

2. Literature Review

2.1 Bisphenol Exposure Pathways

Thermal papers contain free, unpolymerised bisphenols, making them readily transferable to skin and food-contact surfaces. Dermal transfer rates can exceed several milligrams per event under conditions of moist skin, compromised barrier function, or use of hand lotions. Since dermal absorption bypasses first-pass metabolism, a higher proportion of unmetabolised bisphenol enters systemic circulation.

Dietary exposure has traditionally been associated with can linings or environmental contamination; however, recent evidence shows direct transfer from thermal labels applied to food packaging films.

2.2 Toxicological Developments (2020–2025)

• EFSA reduced BPA’s tolerable daily intake to 0.2 ng/kg bw/day, reflecting heightened endocrine sensitivity.
• BPS, once considered safer, is now implicated in ovarian dysfunction, metabolic disruption, and immune modulation.
• Limited data exist for D-8, D-90, TGSA, and PF-201, though several exhibit moderate hazard classifications and endocrine-relevant signals in vitro.

2.3 Regulatory Landscape

• EU Regulation 2024/3190 (effective Jan 2025): full BPA prohibition across most food-contact materials; monitoring of BPS and analogs through 2027.
• Switzerland: 0.02% w/w limit for BPS in thermal paper since 2020.
• California Proposition 65: surge in BPS notices for receipts and UPC labels in 2024–2025.

2.4 Market Trends

Global production of thermal paper (~4 billion USD in 2022) continues to rise due to increasing retail, logistics and e-commerce demand. India imports most thermal jumbo rolls from Korea and Japan. The rapid uptake of BPS-based papers underscores the urgency of evaluating alternatives before widespread adoption.

3. Methodology

3.1 Data Set A: India 2024 Receipt Survey

Sampling

Twenty thermal paper samples were collected across Delhi:

• Restaurants (6)
• Delhi Metro (3)
• ATM receipts (3)
• Grocery shops (5)
• Online suppliers (3)

Laboratory Analysis

• Extraction: 1 g paper in 20 mL tetrahydrofuran (THF), ultrasonication, 60 °C, 60 min.
• Instrumentation: LC–MS (AFIRM method), ESI detection of BPA and BPS.
• Outcome metrics: concentrations in ppm (mg/kg).

3.2 Data Set B: North American Thermal Label Migration Study

Packaging Occurrence Study

• 140 materials: thermal price labels, stickers, cling films, pads, trays.
• Extraction: 95% ethanol, 10 days, 20 °C.
• LC-qTOF-MS analysis; results in μg/cm².

Fish Migration Study

• 24 packaged fish fillets; subdivided into initial, film-contact, and label-contact portions.
• Storage: 5 days at 4 °C.
• Analysis: methanol extraction; LC-qTOF-MS; results in ng/g ww.

Residual Film Migration Tests

• Migration cells (EU 10/2011), 95% ethanol, 10 days, 20 °C.
• Differentiation of label-film vs non-label-film surfaces.

4. Results

4.1 India 2024 Findings: Persistent BPA + Rising BPS

4.1.1 BPA Prevalence

BPA detected in 13/20 samples, ranging:

• 3.63 ppm (lowest)
• 17,400 ppm (highest)

This far exceeds:

• India’s prohibition intent,
• EU limit of 200 ppm.

4.1.2 BPS Substitution

BPS detected in 12/20 samples, range:

• 52.8 – 9,300 ppm

Several rolls marketed as “BPA-free” contained negligible BPA (<5 ppm) but extremely high BPS (up to 3,000 ppm), demonstrating regrettable substitution.

4.1.3 Sector Variability

Sector	BPA (max)	BPS (max)	Notes
International eateries	17,400 ppm	<100 ppm	Heavy BPA use
Local eateries	<200 ppm	9,300 ppm	BPS dominant
Grocery	mixed	mixed	Both BPA and BPS
Metro	both detected	both detected	High public exposure
ATMs	moderate BPA	minimal BPS	Continuing BPA reliance

The highest contamination occurred in restaurant receipts, often representing rapid-turnover POS systems.

4.2 North America 2023 Findings: BPS Migration into Food

4.2.1 Label Composition

BPA was absent in all packaging materials.
BPS was found in:

• 73% of thermal labels
• Mean: 66 μg/cm²
• Max: 193 μg/cm²

Alternative developers were also common:

• D-8: 10% of labels
• D-90: 20%
• PF-201: 28%
• TGSA: 18%

4.2.2 Migration into Fish

Label-contact fish reached:

• BPS: 1140 ng/g ww
• D-8: 230 ng/g ww
• D-90: 3.41 ng/g ww
• PF-201: 1.87 ng/g ww

BPS frequently exceeded the EU SML of 50 ng/g ww, often by >20×.

4.2.3 Residual Migration from Films

Films beneath labels released:

• BPS: up to 33.8 μg/cm²
• D-8: up to 61.8 μg/cm²

indicating film-mediated transfer is a robust pathway.

5. Discussion

5.1 Regulatory Failure and Market Reality

India’s BPA ban did not achieve effective removal of BPA from thermal receipts. Several samples exceed international limits by two orders of magnitude. Limited enforcement, voluntary standard status, and uncontrolled imports contribute to systemic non-compliance.

Conversely, North American markets show complete BPA phase-out but heavy reliance on BPS—a chemical now recognized for endocrine activity and persistence.

5.2 Regrettable Substitution: BPA → BPS

The data exemplify a classic environmental health pitfall:

Removing a known hazardous chemical without evaluating substitutes often results in equal or greater risk from replacement compounds.

BPS migration into food—at levels exceeding regulatory limits—demonstrates that substitution alone is insufficient without safety assessment.

5.3 Dietary vs Dermal Exposure

Migration data suggest dietary exposure from thermal food labels may:

• Equal or exceed dermal receipt exposure for general consumers,
• Significantly impact frequent shoppers and families purchasing packaged fresh foods,
• Pose particular risk for pregnant individuals and children.

5.4 Implications for Thermal Paper and Packaging Industries

• Suppliers can no longer rely solely on “BPA-free” claims;
• Certification must distinguish BPA-free, BPS-free, bisphenol-free systems;
• PF-201, TGSA, and ascorbic-based developers may offer safer profiles but require migration and toxicology evaluation;
• Packaging design must avoid placing thermal labels directly over food-contact films.

6. Conclusion

Across independent studies and continents, evidence demonstrates that:

1. BPA remains widespread in Indian thermal receipts despite formal prohibition.
2. BPS has become the dominant replacement globally, including in India, North America and the EU.
3. Thermal food labels act as a direct contamination route, transferring BPS and developer analogs into foods at levels that exceed regulatory limits.
4. Migration pathways are robust, occurring through films once believed to be barriers.
5. Without coordinated enforcement, risk assessment of substitutes, and adoption of safer developer systems, bisphenol exposure from thermal papers will remain a public health concern.

A transition toward bisphenol-free thermal technologies—supported by regulatory oversight, retailer commitments, and transparent supply chains—is essential to break the cycle of regrettable substitution.

Last Updated on 13/12/2025 by Jota Machinery