Polycarbonate (PC) is synthesised from bisphenol A (BPA; CAS 80-05-7) and diphenyl carbonate via melt transesterification, or from BPA and phosgene via interfacial polymerisation. The reacted BPA unit is a 4,4′-(propane-2,2-diyl)diphenyl carbonate moiety; the regulatory focus is on free BPA monomer remaining from incomplete polymerisation or regenerated by hydrolysis and chain scission during processing. Residual free BPA is partly removed during twin-screw devolatilisation. A corotating twin-screw extruder with an L/D ratio of 32:1 to 44:1 and a vacuum vent pressure of −0.08 MPa to −0.095 MPa is used to strip volatile monomer; melt temperature is maintained between 280 °C and 320 °C. Before injection moulding, PC pellets are dried at 120 °C for 4 h to obtain a moisture content not exceeding 0.02%. If moisture exceeds 0.02% at a barrel temperature above 300 °C, hydrolytic molecular-weight reduction occurs and the free BPA concentration available for migration increases. The distinction between legal applications is therefore not explained by polymer chemistry alone; it is determined by the article type, the contact medium, and the applicable regulatory scheme.

BPA in Polycarbonate: Which Applications Are Still Allowed and Which Are Banned

Within the European Union, the legal status of PC articles containing BPA depends on the article type. Polycarbonate infant feeding bottles are prohibited by Regulation (EU) No 321/2011. Adult food-contact articles remain permitted under Regulation (EU) No 10/2011 if the specific migration of BPA does not exceed 0.05 mg/kg of food or food simulant. Drinking-water contact components are regulated mainly through national approval schemes; medical devices are regulated under ISO 10993-18:2020 and ISO 10993-17; electrical and optical articles are not subject to a BPA food-contact migration limit but may trigger REACH Article 33 communication at 0.1% w/w free monomer.

This asymmetric regulatory architecture means that the polymer itself is not universally banned or permitted. The same PC grade may be prohibited in one moulded article and permitted in another, depending on the applicable exposure scenario.

What Legal Migration Ceilings Apply to Food-Contact Polycarbonate in the EU and US?

For plastic food-contact materials, Regulation (EU) No 10/2011 Annex I, as amended by Commission Regulation (EU) 2018/213, assigns BPA a specific migration limit (SML) of 0.05 mg/kg. Migration testing for reusable PC bottles, food-processor bowls, and sight glasses is performed under the EN 1186 series; specific BPA determination is performed by liquid chromatography with fluorescence detection or LC-MS/MS using protocols derived from the EN 13130 series. A test with simulant B, 3% acetic acid, at 40 °C for 10 days is typical for long-term cold and ambient aqueous contact; fatty food simulants such as D2 or E may be required for oil-containing products. The time-temperature condition is selected from the standardised table in Regulation (EU) No 10/2011 Annex V based on intended use and contact duration. Adult reusable food-contact PC is therefore allowed if the SML is met. US regulation retains PC under 21 CFR 177.1580 as a resin for food-contact use, with extractive specifications applied in the context of good manufacturing practice.

Compliance is enforced per finished article, not per resin grade. A multi-cavity injection-moulded water bottle produced on a 200-ton hydraulic press with a clamp force of 2000 kN and a melt temperature of 295 °C may pass the EU SML when the resin is dried correctly and the residence time is below 5 min. The same grade moulded into an infant bottle is prohibited regardless of migration performance.

A separate prohibition applies to polycarbonate infant feeding bottles. Regulation (EU) No 321/2011 prohibits the manufacture and placing on the market of PC infant feeding bottles in the EU. The restriction is article-specific: the same resin may be moulded into a non-food housing or an adult water bottle, but moulding it into an infant feeding bottle is non-compliant. The prohibition applies even if migration testing would demonstrate BPA below 0.05 mg/kg. Canada listed BPA as a toxic substance under CEPA 1999 Schedule 1 in 2010 and prohibited PC baby bottles under the Canada Consumer Product Safety Act. In the United States, the FDA revoked the authorisation for BPA-based polycarbonate in infant feeding bottles and spill-proof cups in 2012 and 2013 after industry abandonment; the legal route is an application-specific withdrawal, not a migration tolerance.

Drinking-Water Contact Components and National Approval Schemes

Polycarbonate appears in drinking-water contact components such as filter housings, clear manifolds, flow-meter bodies, and pump impellers. There is no harmonised EU parametric limit for BPA in drinking water. Directive (EU) 2020/2184 requires materials in contact with drinking water to be safe, but detailed acceptance is left to national schemes and harmonised standards. EN 12873-1 provides a test method for migration from organic materials intended for use in contact with drinking water; acceptance values are set nationally. France applies the ACS scheme, Germany uses UBA evaluation criteria, and the United Kingdom applies Regulation 31 approvals. A PC filter housing is therefore permitted only if the national approval certificate is based on EN 12873-1 or an equivalent test and the BPA migration value is below the applicable national acceptance level.

Operationally, PC in drinking-water service is limited by hydrolysis at hot chlorinated-water conditions. Sustained contact above 60 °C in chlorinated water can embrittle the surface and increase BPA release; published data for specific PC filter-housing configurations is limited. Under Directive (EU) 2020/2184, the pH range for drinking water is 6.5–9.5; at the alkaline end of this range, carbonate linkages in PC may hydrolyse more rapidly, requiring validation under stagnation conditions in the relevant national approval protocol.

When Polycarbonate Medical Devices Fall Under ISO 10993-18 Instead of BPA Food-Contact Limits

Polycarbonate medical device components such as stopcocks, syringe barrels, anaesthesia canisters, and haemodialysis filter housings are not classified as food-contact materials and therefore fall outside the EU SML of 0.05 mg/kg. They are instead evaluated under Regulation (EU) 2017/745, Annex I General Safety and Performance Requirements. Chemical characterisation is performed according to ISO 10993-18:2020; sample preparation is carried out according to ISO 10993-12:2021; toxicological risk assessment of extractable BPA is performed according to ISO 10993-17. BPA is not banned as a medical-device extractable. It is permitted only if the leachables profile is justified by the toxicological risk assessment for the intended contact duration, route, and patient population.

For gamma-sterilised PC syringes, the terminal sterilisation dose of 25 kGy can reduce molecular weight and increase the extractable BPA fraction. Extractables studies must be performed on the irradiated finished device, not on unirradiated pellets. Polar and nonpolar extraction solvents are selected according to ISO 10993-12:2021; typical vehicles include purified water, ethanol/water mixtures, and isopropanol or hexane. The analytical evaluation threshold is derived from the toxicological risk assessment and the extraction ratio; BPA may appear in the extractable profile at values requiring quantitative toxicological review. USP <661> and USP <661.1> are used for plastic packaging systems; USP <1663> and USP <1664> guide extractables and leachables assessment. If an extractable BPA value is above the analytical threshold, the manufacturer must demonstrate that the estimated patient exposure does not exceed the qualified toxicological limit.

In electrical and electronic equipment, polycarbonate enclosures, optical storage discs, and automotive headlamp lenses are not covered by the EU food-contact BPA SML. RoHS Directive 2011/65/EU Annex II does not list BPA as a restricted substance. The relevant EU-level control is REACH. BPA was added to the Candidate List as a substance of very high concern for endocrine-disrupting properties; an article containing more than 0.1% w/w free BPA monomer triggers communication duties under REACH Article 33. Because the PC repeat unit is a polymer chain and not the free substance, manufacturers quantify residual unreacted BPA by dissolution-precipitation or solvent extraction followed by LC-MS/MS. REACH Annex XVII Entry 66 restricts BPA in thermal paper at 0.02% by weight from 2 January 2020; this restriction does not apply to polycarbonate articles.

Optical-grade PC used for injection-moulded lenses or discs is supplied with residual free BPA controlled against the 0.1% w/w threshold; fabricators must confirm this because processing heat history can increase free monomer. No food-contact migration test is required for these articles unless the article is also placed on the market as a food-contact material.

Residual BPA Generation During Injection Moulding and Extrusion

Residual BPA is not a fixed polymer property. In melt processing, barrel temperatures above 340 °C or residence times above 6 min increase free monomer through hydrolysis and random-chain scission. For a 40 mm reciprocating screw on a 200-ton injection-moulding press, the melt temperature is typically set between 280 °C and 310 °C, the rear zone at 240 °C, the centre zones at 260–280 °C, and the front zone at 290–310 °C. The melt cushion is held at 3–6 mm; hold pressure is usually 60–80 MPa. These parameters keep residence time in the 3–5 min range for many PC grades with a melt volume-flow rate of 10 cm³/10 min at 300 °C under 1.2 kg according to ISO 1133-1:2022. Moisture is measured by a Karl Fischer method in accordance with ISO 15512:2019; the target is 0.02% maximum. Venting or vacuum extraction at −0.08 MPa reduces volatile free BPA but cannot compensate for excessive residence time.

Regrind and post-consumer recycled PC have additional risk. The heat history of re-extrusion hydrolyses carbonate linkages and may increase the free BPA concentration. If regrind levels exceed 25% in a food-contact application, additional specific migration testing is required because the SML compliance of virgin resin does not automatically extend to recycled material. Avoid strongly alkaline cleaning agents above pH 10 at elevated temperature because carbonate linkages in PC hydrolyse rapidly; such exposure can create surface crazing and increase BPA release. Published data for specific recycled PC food-contact configurations is limited.