Testing and documentation, and why our method fits product certification

Two approaches to the same question

Every microplastic certification is trying to answer one question: will this product expose people to microplastics during normal use? There are two ways to approach it. One tests finished products in a laboratory and measures the particles found. The other reviews what the product is made from, since a product's materials determine whether it can shed plastic in the first place. Both are legitimate. They answer the question at different points and with different tradeoffs.

What laboratory testing establishes, and its limits

A laboratory test measures the particles present in a specific sample at a specific moment, using a specific method. That is useful information, but three well-documented limits matter for product certification.

First, testing detects rather than prevents. A result describes the unit that was tested under the conditions of the test. It does not, on its own, establish what the product is made from or how a different unit will behave after months of wear.

Second, methods disagree. The two dominant techniques for identifying microplastics, micro-FTIR and micro-Raman, can return materially different results on the same samples. A European Commission Joint Research Centre review of analytical methods and related peer-reviewed work document substantial variation between methods. In one 2023 comparison of the two techniques on the same drinking water samples, the estimated human intake calculated from the micro-FTIR data was roughly 332 times lower than the figure calculated from the micro-Raman data. A certification whose result depends heavily on method choice is difficult to defend as a single objective standard.

Third, every method has a size floor. Micro-FTIR is generally limited to particles above roughly ten micrometres, and micro-Raman to roughly half a micrometre to one micrometre, though the exact floor depends on the instrument and method used. A test result of "no microplastics detected" always means "none detected above the method's size threshold," not "none present." Testing therefore cannot, by itself, support an absolute microplastic-free claim.

Testing is also slow and costly at the scale of a product catalog. The same Joint Research Centre work reports per-sample analysis times measured in hours and identifies time and the costs associated with it as barriers to routine analysis. For a brand certifying a product family across several sizes and finishes, testing every configuration is expensive for a conclusion that the product's materials already determine.

What documentation review establishes

Whether a product sheds microplastics is decided upstream, by the materials in its exposed surfaces, the coatings and additives applied to them, and how they are made. Documentation review evaluates those choices directly. We examine the bill of materials for every exposed component, supplier specifications and attestations, and manufacturing details, and we assess them against a published standard with a fixed definition of disqualifying materials.

Because the review is about materials rather than a single sampled unit, its conclusion applies to every product built to the same specification, not just to one item on one day. It is reproducible: two reviewers applying the same standard to the same documentation reach the same result, which is not always true of a particle count. And it is transparent, because the basis for each decision is a written determination a brand can show to retailers, regulators, and its own compliance team.

Why we use documentation review

We built certification around documentation for three reasons. It evaluates the thing that actually determines the outcome, a product's materials, rather than inferring it from a downstream measurement. It is reproducible against a fixed standard, so a certification means the same thing from one product to the next. And it avoids a structural conflict of interest: we review evidence that already exists rather than selling laboratory work whose results we then certify. A certifier that profits from the testing it requires has an incentive the review should not have.

This is also why our standard is absolute rather than comparative: absolute in the sense that it admits no contamination threshold and no partial credit at the level of materials, not in the sense of asserting a particle count of zero in any finished unit. Because we evaluate materials directly, we can require that exposed surfaces contain no plastics or other microplastic-forming materials, and resolve genuine ambiguity against certification. A method that depends on detection thresholds cannot make that commitment as cleanly.

When testing still helps

None of this makes testing the enemy. When a brand already holds independent laboratory reports relevant to microplastic shedding or polymer stability, we accept them as part of the evidence. Where documentation genuinely cannot resolve a material question, we may recommend that a brand obtain testing from an independent laboratory of its choice. We simply do not perform or sell that testing ourselves, and we do not make it a precondition when a product's materials already establish the answer.

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