Microplastics

EU focus

Regulatory references on this page are to EU frameworks: Regulation (EU) No. 10/2011 on plastic food contact materials, and EFSA scientific assessments. The scientific studies cited are international; the regulatory response discussed is EU-specific.

Microplastics in beer is a topic where the intuition is wrong, the data is surprising, and the practical implications are not what most people expect. This page works through what the evidence actually shows, where the genuine concerns lie, and what a proportionate response looks like for homebrewers.

The short version: the dominant sources of microplastics in beer are environmental and process-related, not equipment-derived. Glass-bottled beer contains more microplastics per litre than PET-bottled beer in some studies. Chemical leaching from plastics — the subject of the toxicology page — is a distinct concern from particulate microplastics and is better characterised by the existing regulatory framework. Physical damage to plastic equipment increases particulate release. These are the practical implications that fall out of the evidence.

Two different phenomena

Before addressing the evidence, the distinction between microplastics and chemical leaching must be clear, because they are regularly conflated — even in scientific literature — and the conflation produces confused conclusions.

Microplastics (MPs) are physical particles of polymer material that detach from surfaces and enter the beverage as solid matter. They are measured in particles per litre. Their toxicological concern is related to the particles themselves — their size, their chemistry, and their capacity to carry adsorbed chemical contaminants.

Chemical leaching is the migration of dissolved molecular species — monomers, oligomers, plasticisers, polymer additives — from plastic material into the liquid phase without producing visible particles. It is measured in mg/kg food simulant or in ppm in the beverage. Its toxicological concern is about specific chemical entities with known or partially characterised biological activity.

These are different mechanisms, different measurement methodologies, and different regulatory frameworks. A material can leach concerning chemicals while producing negligible particulate MPs (e.g. PC/BPA). A material can produce detectable particulate MPs while having a benign chemical leaching profile (e.g. PP). Treating them as the same concern leads to misidentified risks and misdirected responses.

What the research actually shows

Glass-bottled beer contains more microplastics than PET

This is the finding that most disrupts the intuitive assumption that plastic packaging is the primary source of microplastics in beer.

A 2025 assessment by the French food safety authority ANSES found that beverages in glass bottles contained the highest microplastic concentrations across the beverage types studied — in some measurements, 50 times more than equivalent beverages in plastic bottles or cans.¹ For beer specifically, glass-bottled samples averaged approximately 133.7 microplastic particles per litre.¹

The source of microplastics in glass-bottled beer is not the packaging — glass does not release polymer particles. The sources are the production environment, the raw materials (water, malt, hops — all carrying environmental contamination), the processing equipment (much of which is plastic in commercial production: hoses, seals, gaskets, pump components), and atmospheric deposition during filling.²

This finding is important not because it makes glass packaging "worse" than plastic — it is not a straight comparison, because the particle types differ — but because it establishes that the dominant sources of MPs in beer are environmental and process-related, not packaging-related. A homebrewer using a PET fermenter is not meaningfully elevating their beer's microplastic content compared to commercial production.

Cellulose dominates the particle count

Many studies of microplastics in beer report particle counts that include cellulosic particles — natural (cotton, wood) and semi-synthetic (rayon, viscose) fibres — alongside synthetic polymer particles.³ The distinction matters because cellulosic particles are not synthetic polymers and carry a different (generally lower) biological concern profile. When synthetic polymer-specific counts are separated out from total particle counts, the synthetic polymer microplastic burden in beer from any packaging type is substantially lower than headline numbers suggest.

Temperature is the critical variable for plastic contact

Hot water immersion of plastic materials leads to significantly elevated release of submicron particles compared to cold contact.⁴ This has a direct practical implication: hot-side brewing processes that use plastic equipment — plastic mash tuns, hot liquor tank liners, plastic kettles — produce substantially more plastic particle release than cold-side processes.

Fermentation equipment (PET FermZilla, PP bucket, Oxebar mini keg) operates at cold-side temperatures. Ambient-temperature PET contact with beer produces particle release orders of magnitude lower than hot-side plastic contact. The FermZilla is not a meaningful source of microplastics in beer relative to hot-side plastic use.

This is a genuine argument for using stainless steel or copper on the hot side — not because cold-side PET is a serious microplastics source, but because hot-side plastic contact is more significant and stainless avoids it entirely.

The measurement methodology problem

A significant fraction of the uncertainty in microplastics research stems from measurement methodology. Most studies use optical microscopy, Raman spectroscopy, or FTIR spectroscopy to identify and characterise particles. These methods have different lower detection limits, different particle size ranges, and different abilities to distinguish synthetic polymers from natural materials. Studies that disagree substantially often differ in methodology rather than in the actual particle content of the beverage.

Nanoplastics — particles below 1 micrometre — are essentially undetectable with current standardised methods. Their biological properties (capacity to cross cell membranes, different surface area to volume ratio) may differ substantially from larger microplastics, but the methodology to characterise them in food systems is not yet established at the level needed for regulatory use.⁵

What this means for homebrewing

The glass carboy is not the safer option for microplastics

A homebrewer who switches from a PET FermZilla to a glass carboy to avoid microplastics is not accomplishing the goal they intend. Glass is not a source of synthetic polymer particles, but the dominant sources of MPs in homebrewed beer — the brewing water, the raw materials, the atmosphere — are the same either way. The packaging material is a minor variable in the total microplastic burden.

This is not a recommendation to ignore plastic quality. It is a calibration of where the concern is proportionate.

Physical damage increases particle release

The one practical recommendation from microplastics research that homebrewers can act on directly: scratched, abraded, or chemically degraded plastic surfaces release more particles than intact surfaces.

This connects to the "no abrasive cleaners" guidance that appears throughout the equipment sections. Scourers, abrasive powders, and rough sponge pads scratch the surfaces of PET, PP, and HDPE equipment. The scratches increase surface area; they increase the release of sub-surface polymer fragments during agitation; they create crevices that trap soil and may trap particles as they form. Avoid all abrasive cleaning on plastic equipment — not only because scratching creates contamination traps, but because intact surfaces release fewer particles than damaged ones.

Equipment with visibly scratched, discoloured, or chemically attacked surfaces should be replaced. Not primarily because of acute contamination risk, but because degraded surfaces represent a compromised material that no longer provides the clean, intact contact surface that food safety requirements assume.

Chemical leaching is the better-characterised concern

For plastic materials in contact with beer, chemical leaching — the migration of specific molecular species with known toxicological profiles — is better characterised than particulate MP contamination, has established regulatory limits under Regulation (EU) No. 10/2011, and has practical mitigation strategies that the materials register addresses directly.

The recommendation to avoid PC (BPA), avoid POM in contact with ABNS (formaldehyde), avoid NR/SBR (nitrosamines), and use equipment with EU food contact compliance documentation is the correct response to chemical leaching — and it is a more tractable response than attempting to minimise particulate MP exposure from inherently contaminated environmental sources.

Choosing compliant equipment matters

Equipment manufactured to comply with Regulation (EU) No. 10/2011 has been tested for specific substance migration under standardised conditions. This compliance does not eliminate all migration concerns — the toxicology page addresses where standardised testing conditions differ from actual use conditions — but it provides a meaningful baseline of assessed safety that unlisted, undocumented materials do not.

Prefer equipment with:

A Declaration of Conformity (DoC) referencing EU Regulation 10/2011 or equivalent
Material identification (PP, HDPE, PET, SAN — not just "food grade")
Manufacturer documentation that allows the material to be traced to the compliance assessment

The Witre PP bucket, for example, carries a DoC from Plast-Box S.A. referencing EU 1935/2004 and 10/2011, with migration testing by J.S. Hamilton Poland (PCA No. AB 079).⁶ This level of documentation is the standard that should apply across brewing equipment — and the documentation problem page addresses the gap between this standard and what the homebrewing market typically provides.

The honest uncertainty statement

The science of microplastics and nanoplastics in food is moving rapidly, and the regulatory framework is catching up more slowly. What is established: microplastics are measurable in beer universally, across all packaging types, in concentrations that vary with production method and environment. What is not established: whether the concentrations found in beer cause harm at doses typical of beer consumption, what particle sizes represent the threshold for biological concern, and whether nanoplastics — which are currently undetectable in food systems by standardised methods — are present in relevant concentrations.

The appropriate response to this uncertainty is the precautionary position: minimise unnecessary plastic contact where this is practical and low-cost, prefer documented EU food-contact-compliant materials, maintain equipment in intact condition, and avoid hot-side plastic contact where stainless alternatives exist. This is proportionate to the evidence without over-reacting to it.

ANSES (Agence nationale de sécurité sanitaire de l'alimentation, de l'environnement et du travail), Assessment of microplastics in beverages (2025 data) — referenced via wasserdreinull.de, Microplastics in Beer (accessed April 2026 from wasserdreinull.de). Glass-bottled beer: ~133.7 particles per litre; up to 50× more than plastic or can in some measurements. ↩ ↩²
Rafiee, M. et al., A microscopic survey on microplastics in beverages: the case of beer, mineral water, and tea — accessed April 2026 from researchgate.net. Atmospheric deposition and production contamination identified as sources. ↩
ScienceDirect, Microplastic concentration in beverages including beer — accessed April 2026 from sciencedirect.com. Beer highest at 95.5 ± 91.8 items per litre; majority of particles were cellulosic rather than synthetic polymer. ↩
Frontiers in Sustainable Food Systems, Hot water immersion and plastic particle release — accessed April 2026 from frontiersin.org. Hot immersion significantly increases submicron particle release vs. cold contact. ↩
Taylor & Francis, Risk assessment uncertainties for microplastics in food (2024) — accessed April 2026 from tandfonline.com. Insufficient data to assess health risks; nanoplastics not characterised in food systems. ↩
Plast-Box S.A. / Witre AS, Declaration of Conformity for PP food containers (2015) — accessed April 2026 from witre.se; migration tested by J.S. Hamilton Poland, PCA No. AB 079 · Witre PP Bucket DoC.pdf. ↩

Two different phenomena​

What the research actually shows​

Glass-bottled beer contains more microplastics than PET​

Cellulose dominates the particle count​

Temperature is the critical variable for plastic contact​

The measurement methodology problem​

What this means for homebrewing​

The glass carboy is not the safer option for microplastics​

Physical damage increases particle release​

Chemical leaching is the better-characterised concern​

Choosing compliant equipment matters​

The honest uncertainty statement​

Footnotes​