Vetting Methodology

Our goal is to help UK consumers make informed choices about microplastics in everyday products. This page explains how we research and rate products, what data sources we use, and the limitations of our approach.

Our 3-Tier Rating System

Based on available ingredient data, each product on our site receives one of three status ratings:

Verified Free

We can identify the materials or ingredients that meet your food, drink or skin, and they are not materials known to shed microplastics. This covers inert materials — glass, stainless steel, cast iron, ceramic, natural rubber, untreated wood and cured food-grade silicone — and formulations whose published ingredient list contains no synthetic polymers. We assign this status when a manufacturer's declared composition or ingredient list is specific enough to check against known microplastic ingredients and synthetic polymer databases. It reflects what the product is made of, not a test we have run on it.

Likely Free

We could not fully establish what the product is made of, or the material sits in a class where the published evidence is genuinely mixed. Typical cases are an undisclosed proprietary lining or coating, a composite whose binding agent is not published, or a material that researchers classify inconsistently. This rating is not a signal that the product does shed microplastics — it means we could not get far enough to say that it does not.

Contains Microplastics

A plastic polymer forms the surface that meets your food, drink or skin, or a synthetic polymer appears in the ingredient list — polyethylene, polypropylene, nylon, polyethylene terephthalate or Tritan copolyester, among others. Water-soluble synthetic polymers — PVOH and PEG — are the exception to that rule and sit a tier lower; we explain why below. For some of these the shedding is well documented in published research. For others the material is a plastic in direct, sustained contact and the shedding data is limited rather than reassuring; we treat missing data as unresolved, not as evidence of safety. These products are included on our site for comparison purposes — to help consumers understand which products to avoid.

Which Part of the Product We Rate

Our rating tracks the surface that touches what you consume, not the whole object. A stainless steel bottle with a polypropylene lid is rated on the steel, because the steel is what the water sits against between refills — the plastic lid is listed in the product's materials but does not change the rating. The same rule applies in reverse: a bottle with a plastic body is rated on that body even when the lid, seal or valve is steel or silicone. Where a product has more than one contact material, we rate the one in sustained contact with your food or drink.

A Note on Silicone

Cured food-grade silicone is a crosslinked elastomer rather than a thermoplastic, and it does not shed microplastic fragments the way conventional plastics do in normal use. We therefore rate it alongside glass and steel when it forms the contact surface. Silicone can release siloxanes, but siloxanes are a separate chemical question from microplastics, and our ratings are specifically about microplastics rather than chemical inertness in general. One genuine caveat: silicone degrades under sustained high heat, heavy abrasion and long-term wear, so an item that has turned sticky, discoloured, cracked or tacky is a different case and is worth replacing.

A Note on Dissolvable Pods and Water-Soluble Polymers

Dissolvable laundry capsules, dishwasher tablets and cleaning "drops" are built around water-soluble synthetic polymers — polyvinyl alcohol, written PVOH or PVA — and the same class covers polyethylene glycol, or PEG, which appears in detergents and personal care formulations. These are synthetic polymers. They dissolve rather than staying behind as visible particles, but dissolving is not the same thing as not being plastic, and what happens to them after they leave your machine is an open question rather than a settled one.

The EU microplastic restriction — Commission Regulation (EU) 2023/2055, which added entry 78 to Annex XVII of REACH — defines "synthetic polymer microparticles" and then excludes several classes of polymer from that definition, among them "polymers that have a solubility greater than 2 g/L". A polymer that dissolves is therefore outside what the restriction covers. That is a decision about the scope of a rule, not a finding that the substance is harmless.

The UK advertising regulator has made that distinction explicitly. On 2 April 2025 the Advertising Standards Authority upheld complaints against OceanSaver Ltd over "plastic-free" and "zero microplastics" claims, finding the evidence the company submitted did not substantiate them. On the regulation specifically, the ASA said: "While the 2023 Regulation was silent on whether PVOH was designated as a microplastic, we considered its omission from the Regulation did not, per se, mean it was not a plastic or source of microplastics."

We therefore rate products whose active ingredient is a water-soluble synthetic polymer as Likely Free. Verified Free would tell you a question is closed when it is not. Contains Microplastics would tell you the material behaves like polyethylene beads in a face scrub, which it does not. Likely Free is the accurate middle: a synthetic polymer that the regulation's own definition leaves out, that the UK advertising regulator has ruled cannot be called plastic-free on the strength of that exclusion alone, and that we are not in a position to settle either way. We would rather tell you the debate exists than pick a side you would find out about anyway.

Data Sources

Our research draws on the following publicly available sources:

Manufacturer ingredient lists — product packaging, official websites, and safety data sheets provided by manufacturers
ECHA (European Chemicals Agency) — the EU/EEA database of registered substances, including microplastic definitions under the REACH restriction
Beat the Microbead — the Plastic Soup Foundation's database of microplastic ingredients in cosmetics and personal care products (where applicable)
Published research — peer-reviewed studies on microplastic release from specific materials (e.g., polypropylene cutting boards, nylon tea bags)
UK retailer product descriptions — material specifications listed by Amazon.co.uk, John Lewis, and other UK retailers

Research Process

For each product we evaluate, we follow these steps:

Identify the product's materials and ingredient composition from available sources
Cross-reference ingredients against known microplastic and synthetic polymer databases
Evaluate the product's material type against published research on microplastic shedding
Assign a rating based on the weight of available evidence
Document the rationale and note any uncertainties

Important: What We Can and Cannot Say

Our analysis is based on available ingredient data. We do not conduct laboratory testing. Product formulations may change without notice. Manufacturers may update ingredients between production batches.

We recommend checking product packaging for the latest ingredient lists and formulation details before making purchasing decisions. Our ratings represent our assessment at the time of review, based on the data available to us.

We make no health claims. Microplastic Free provides factual information about product ingredients and materials. We do not provide medical advice or make claims about health outcomes. Consult appropriate professionals for health-related decisions.

Re-Verification

We aim to re-verify product information periodically. Each product listing includes a "last verified" date so you can see how recently the data was checked. If a product's formulation changes, we update the rating accordingly.

Report an Inaccuracy

If you believe a product rating is incorrect, or if you have information about a product formulation change, we want to hear from you. Please contact us at hello@microplasticfree.co.uk with the product name and details. We investigate all reports and update ratings where warranted.

Last updated: July 2026