###### Abstract  
Bisphenol A (BPA) is a known substance that is found in food contact materials as an intentionally added as well as a non-intentionally added substance. Traces of BPA were found as a non-intentionally added substance in recycled PET (rPET). In 2023, the EFSA proposed a new TDI of 0.0002 ug/kg bw/d, which is lower than the previous (temporary) TDI of 4 ug/kg bw/d by a factor of 20,000. The TDI of 0.0002 ug/kg bw/d would translate for a default 60 kg person eating one kilogram of food into a migration limit of 0.012 ug/kg in the food. This very low migration limit is a challenge to measuring BPA levels in food. A solution is to use migration modeling to establish maximum concentrations in rPET for different food contact applications. Precise diffusion coefficients for BPA in PET were determined within this study by use of migration kinetics. In June 2024, the European Commission proposed a new migration threshold limit for BPA of 1 ug/kg, which should be understood as a detection limit. From the results of this study, it can be concluded that a BPA concentration in the PET bottle wall of 297 mg/kg (3% acetic acid), 255 mg/kg (10% ethanol), and 192 mg/kg (20% ethanol) after storage for 365 d at 25 \({}^{\circ}\)C is in compliance with the migration threshold limit of 1 ug/kg. These maximum concentrations are far above the measured BPA concentrations on rPET bottles in Europe between 2019 and 2023. Therefore, the new proposed migration threshold limit for BPA cannot be exceeded. Bisphenol A; polyethylene terephthalate; diffusion coefficients; exposure; food safety; migration modeling +
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2003, the SCF set a temporary tolerable daily intake (TDI) of 10 \(\mathrm{\SIUnitSymbolMicro g}\)/kg bw/d based on an animal experimental no observed adverse effect level (NOAEI) of 5000 \(\mathrm{\SIUnitSymbolMicro g}\)/kg bw/d and applying an uncertainty factor of 500. As a consequence, in 2004, BPA was listed in EC Directive 2002/72/EC with a reduced SML of 600 \(\mathrm{\SIUnitSymbolMicro g}\)/kg food [11]. Following a re-evaluation by the European Food Safety Authority (EFSA), the NOAEI was still considered to be valid, but the uncertainty factor was revised from 500 to 100 based on new toxicological evidence. As a consequence, in 2006, the EFSA established a full tolerable daily intake (TDI) of 50 \(\mathrm{\SIUnitSymbolMicro g}\)/kg bw/d [12]. However, the European (EU) Commission did not revise the SML back to 3 mg/kg food but left the restriction unchanged at 600 \(\mathrm{\SIUnitSymbolMicro g}\)/kg food. Due to repeated criticism from European national agencies, the EFSA reviewed new scientific information several times but did not find sufficient evidence to revise the NOAEI of 5000 \(\mathrm{\SIUnitSymbolMicro g}\)/kg bw/d until 2011 [13]. In 2012, the EFSA decided to undertake a full re-evaluation of BPA based on the most recent scientific evidence and, in 2015, published an opinion with a temporary TDI of 4 \(\mathrm{\SIUnitSymbolMicro g}\)/kg bw/d [14]. In the follow-up in 2018, the EU Commission revised the SML of 600 \(\mathrm{\SIUnitSymbolMicro g}\)/kg food to an SML of 50 \(\mathrm{\SIUnitSymbolMicro g}\)/kg food, also taking an allocation factor of 20% to include exposure from other sources into account [15]. With this measure, BPA was also banned from being used in the manufacture of FCMs for infant formula as well as baby and young children's foods. In 2020, the EU Commission, relying on the same temporary TDI, established a threshold limit of BPA in drinking water of 2.5 \(\mathrm{\SIUnitSymbolMicro g}\)/L, set to take effect in January 2026 [16]. In the meantime, in 2016, based on a number of uncertainties related to the toxicological evaluation of BPA, the EU Commission mandated the EFSA to re-evaluate the risks to public health from the presence of BPA in foodstuffs and to establish a tolerable daily intake (TDI). For this re-evaluation, a pre-established protocol was used that had undergone public consultation.