# Microplastics Lab Testing: Does Your Data Support A Claim?

> The Wellness Quality Institute helps you verify microplastics lab data before making public claims. Check your report today.

**Published:** 2026-10-13 | **Updated:** 2026-10-31 | **Author:** mihir
**URL:** https://www.wellnessqualityinstitute.com/articles/microplastics-lab-testing-verification-process
**Type:** post

**Categories:** Certification

![Microplastics Lab Testing: Does Your Data Support A Claim?](https://wellnessquality.sites.aigrowthagent.co/wp-content/uploads/sites/93/2026/10/1791800348471-e584768c11e3-1024x572.webp)

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## Content

*Written by: Scott Steveson, Specialist, Wellness Quality Institute*

## Key Takeaways

- Self-reported lab reports showing “no microplastics detected” need independent verification of the laboratory, method, controls, and documentation before supporting public claims.
- Verification reviews documents against clear criteria, including accreditation scope, sampling methods, analytical techniques, quality-control results, and stated report limitations.
- Most brands discover their existing data supports a narrower, more specific claim once they complete the verification checklist on accreditation, blanks, spike recoveries, and size-fraction reporting.
- Verification stops short of absence claims because current detection methods cannot prove zero plastic across all particle sizes, polymers, and production lots outside the tested scope.
- The Wellness Quality Institute reviews existing laboratory datasets through its Plastic-Free Pathway Verification program, using defined criteria instead of running new tests or certifying products as plastic-free.

[Find out if your lab report can support a public claim.](https://www.wellnessqualityinstitute.com/?utm_term=microplastics-lab-testing-verification-process&utm_campaign=ai_growth_agent)

## Who This Guide Helps And What Key Terms Mean

This guide speaks to brand-side sustainability leads, quality managers, and procurement managers who already have a lab report, a lab quote, or a shortlist of labs. They want to know whether the result can be trusted and whether it can support anything said publicly.

Several terms appear throughout. The list below explains them in plain language:

- **Verification** – independent review of existing data against defined criteria.
- **Validation** – the laboratory’s own proof that a method performs as intended.
- **Scope** – the specific methods, sample types, and ranges a laboratory is accredited to perform.
- **Detection floor** – the smallest particle size a method can reliably identify.
- **Reporting limit** – the lowest concentration or count a laboratory will report with confidence.
- **Chain of custody** – the documented record of how a sample was handled from collection through analysis.
- **Accreditation** – formal recognition by an accreditation body that a laboratory meets [ISO/IEC 17025](https://www.iso.org/standard/66912.html) for a defined scope.
- **Blank correction** – adjustment of results to account for contamination introduced during sampling or analysis.
- **Substantiation** – evidence strong enough to support a public claim.

## The Microplastics Lab Testing Verification Process, Step By Step

### Step 1: Verify The Laboratory’s Credentials

Start with the laboratory’s accreditation certificate number and the accreditation body’s name. Then open the accreditation body’s public directory, such as [ANAB (the ANSI National Accreditation Board)](https://casrai.org/dictionary/term/anab-ansi-national-accreditation-board), A2LA, NVLAP, or PJLA, and confirm the laboratory appears under its legal entity name, not a parent company or brand name. Next, open the current scope of accreditation document and confirm that the specific microplastics method and the specific matrix are explicitly listed.

[ISO/IEC 17025 accreditation is granted method by method and site by site, not as a blanket approval for all testing.](https://casrai.org/guides/iso-17025-accreditation-verify-supplier) A laboratory can be genuinely accredited yet perform a specific test outside its published scope. When the scope does not name the method and matrix, the accreditation claim does not support the result. A laboratory-provided certificate or marketing statement can be outdated or tied to a different facility, so the public directory remains the primary check.

![Scientists in white coats working with samples and microscopes in a laboratory.](https://cdn.aigrowthmarketer.co/1784829434095-0fc8fbcf29fa.webp)**Only a small number of laboratories can genuinely test for microplastics, and capability varies by instrument and method. WQI reviews a company's existing third-party laboratory data against a defined standard — it does not run the tests itself.**

### Step 2: Review Sampling And Sample Preparation

Next, review how the sample was collected and handled. Look for documentation of the collection method, container type, volume collected, and preservation steps. Confirm non-plastic tools were used, such as glass, stainless steel, or specialized metal sieves.

For drinking water, California’s methods allow large volumes collected by inline sieving, in some cases up to 1,500 liters. Field blanks and procedural blanks should appear alongside the sample. When sampling methodology is missing, the result cannot be evaluated for contamination risk.

### Step 3: Review The Analytical Identification Method

Now confirm which analytical method the lab used. Look for a specific method name such as SWB-MP1-rev1 (infrared spectroscopy), SWB-MP2-rev1 (Raman spectroscopy), or an equivalent method with documented validation. The method’s validated particle-size range should match the range reported in the results.

Infrared spectroscopy is validated above 50 µm through 5,000 µm, and Raman spectroscopy above 20 µm through 5,000 µm. The 1–20 µm fraction is not validated under either method. When a report claims detection below the method’s validated floor, the finding reaches beyond what the method can reliably support.

![Colorful plastic fragments in water inside a laboratory petri dish.](https://cdn.aigrowthmarketer.co/1784829410323-fb401fc7b1e4.webp)**Microplastics are particles smaller than five millimeters. Current methods can count and identify them at the upper end of that range, but reliable measurement falls away as particles get smaller — a limit that shapes every honest claim.**

### Step 4: Review Quality-Control Results

Quality-control results show whether the numbers can be trusted. Look for procedural blanks, spike recoveries, and replicates. A contaminated procedural blank invalidates a finding, because a blank that contains microplastics makes the sample result indistinguishable from background contamination.

Spike recoveries demonstrate that the method can recover known particles at acceptable rates. [Inconsistent reporting of blanks, replicates, recovery tests, and validated detection limits is a major reason microplastic datasets cannot easily be compared.](https://mdpi.com/2071-1050/18/18/9537) When blank results are missing or spike recoveries are not reported, the dataset lacks the quality-control evidence needed for verification.

### Step 5: Review The Final Report And Its Stated Limitations

Finish by reading the report as a whole. Start with counts by size fraction rather than a single aggregate figure, because a single number hides which particle sizes were actually measured. Polymer identities should be reported against a defined panel, at minimum PE, PP, PET, PS, PVC, PA, PC, and PMMA, so the reader knows which plastics were tested for and which were outside scope.

Reporting limits and chain of custody should also appear, since without them the result cannot be tied to a known sample or a known detection threshold. Data recency matters as well, because verification is locked to the sampling date of the most recent accepted dataset. Finally, the report should state its method limitations. A report that presents a single number cannot support a defensible claim unless it also breaks that number down by size fraction, identifies the polymers tested for, and explains its method limitations.

[See whether your existing lab data meets the verification standard.](https://www.wellnessqualityinstitute.com/?utm_term=microplastics-lab-testing-verification-process&utm_campaign=ai_growth_agent)

## The Accreditation-Scope Trap In Microplastics Testing

This trap is the most common and most consequential error in microplastics claim substantiation. [ISO/IEC 17025 accreditation is issued for a fixed cycle and can be suspended, restricted, or withdrawn between full reassessments.](https://casrai.org/guides/iso-17025-accreditation-verify-supplier) It is also granted method by method and site by site.

The scope of accreditation document normally identifies the specific test methods or measurement parameters, applicable measurement ranges, and associated uncertainties. For microplastics work, look for the actual analytical method or an explicitly identified laboratory-developed method in the scope, not a generic statement that the laboratory is ISO/IEC 17025 accredited. [A scope for drinking water covers only drinking water.](https://casrai.org/guides/iso-17025-accreditation-verify-supplier) It does not automatically extend to bottled water, wastewater, sludge, sediment, food, textiles, or consumer products.

The accreditation body’s public directory is the preferred independent verification source. Search it using the laboratory’s legal name or accreditation certificate number, then confirm the listing is current or active. From there, open the current scope-of-accreditation document linked from the directory. [A laboratory-provided certificate or marketing statement should be treated as supporting information, not the primary proof.](https://casrai.org/guides/iso-17025-accreditation-verify-supplier)

Organizations that use the California framework as a reference point often treat California ELAP accreditation for the applicable SWB microplastics method as the preferred qualification. ISO/IEC 17025 with method and matrix explicitly in scope also qualifies. Other independent laboratories may qualify through documented method-equivalence review. Companies may choose to use this framework as a technical reference point.

## Blank Controls And Spike Recoveries As Make-Or-Break QC Evidence

Procedural blanks and spike recoveries provide the quality-control evidence that determines whether a finding can be trusted. As noted in Step 4, a contaminated procedural blank invalidates a finding. Contamination can be introduced during sampling, transport, or analysis, which is why the blank must be documented alongside the sample.

A 2024 study in *PNAS* by [Qian et al. reported roughly 240,000 plastic particles per liter of bottled water, most of them nanoplastics](https://www.pnas.org/doi/10.1073/pnas.2300582121). A [subsequent *PNAS* commentary found the study’s procedural blanks appeared contaminated and its quality control inadequate](https://www.pnas.org/doi/10.1073/pnas.2411099121). The critique turns on blank controls, the same contamination controls a verification review examines. The finding and the critique belong together, because each one changes how the other is interpreted.

![Fragments of plastic suspended in blue water below the surface.](https://cdn.aigrowthmarketer.co/1784829388732-c6255482b477.webp)**Plastic doesn't disappear — it fragments. These secondary microplastics are the breakdown products of everyday objects, and independent research now detects them across the water supply. Detection, though, establishes presence, not absence.**

A separate widely repeated claim states that people ingest roughly 5 grams of plastic weekly, “a credit card’s worth,” based on a [2019 WWF-commissioned analysis](https://wwf.panda.org/wwf_news/?348337%2FRevealed-plastic-ingestion-by-people-could-be-equating-to-a-credit-card-a-week). The underlying estimates range from roughly 0.1 to 5.5 grams depending purely on an assumption about particle shape, and later research lands orders of magnitude lower. This figure illustrates how a viral number can outrun its evidence.

Blank controls show whether a result is contaminated, yet they do not show whether the method itself fits the sample. That judgment depends on matching the analytical technique to the matrix.

## Method-To-Matrix Matching For FTIR, Raman, And Pyrolysis GC-MS

Each analytical method answers a different question, and selecting the wrong one for a given matrix produces a result that cannot support a claim. The table below compares three common methods on the factors that matter most for claim substantiation: validated particle-size range, what the method measures, and whether the sample is destroyed during testing.

| Method | Validated Range | Output | Destructive |
| --- | --- | --- | --- |
| SWB-MP1-rev1 (Infrared) | >50 µm to 5,000 µm | Particle count, polymer ID | No |
| SWB-MP2-rev1 (Raman) | >20 µm to 5,000 µm | Particle count, polymer ID | No |
| [Pyrolysis GC-MS](https://mdpi.com/2673-8929/5/2/99) | Method-dependent | Mass concentration | Yes |

[Pyrolysis GC-MS is valuable for polymer-specific mass quantification.](https://mdpi.com/2673-8929/5/2/120) However, it is destructive and does not provide information on particle size, shape, or number. It answers a different question than spectroscopic methods. The California drinking-water definition reaches down to 1 nanometer, which is thousands of times smaller than any validated method can currently see. That gap explains why no laboratory can certify a product as plastic-free.

The method must also match the matrix. A method validated for drinking water does not automatically apply to wastewater, food, or biological tissue.

## What A Defensible Microplastics Report Must Document

A report that can support a public claim must document all of the following:

- Counts by size fraction rather than a single aggregate figure
- Polymer identities against a defined panel, at minimum PE, PP, PET, PS, PVC, PA, PC, and PMMA
- Reporting limits
- Blank corrections
- Chain of custody
- Data recency
- Stated method limitations

Visual identification alone never suffices. Counted particles, or an approved statistically valid subsample, must be chemically confirmed. [NIST researchers have noted that particle-size measurements have limited precision and accuracy, and that uncertainty must be tied to reported size fractions rather than omitted, especially near a decision threshold or the instrument’s practical resolution.](https://nist.gov/news-events/news/2026/08/nist-researchers-correct-common-error-confounding-nanotech-measurements)

## Why Verification Stops Short Of An Absence Claim

Verification can show what the data supports, yet it cannot prove that no plastic is present. Detection can only establish that a particle is present and identified as a polymer. As noted in the Key Takeaways, detection establishes presence but cannot establish absence.

Proving that no plastic is present requires ruling out everything the method cannot see, including every particle below the detection floor, every polymer outside the tested panel, and every production lot that was not sampled. That claim sits beyond the reach of current methods.

The Wellness Quality Institute (WQI) exists at this boundary. WQI’s Plastic-Free Pathway Verification, governed by WQI-CS-01, independently reviews a company’s existing laboratory dataset, testing methodology, product scope, and supporting controls against defined criteria focused on particle size and polymer type. WQI does not run laboratory tests or certify that any product is free of plastic. Verification shows that a company is on a verified pathway toward plastic-free standards.

*WQI Plastic-Free Pathway Verification does not certify that a product contains zero plastic, microplastics, or nanoplastics. It shows that the company is on a verified pathway toward plastic-free standards. Verification applies only to the reviewed products, submitted datasets, tested ranges, polymer panels, production or sampling periods, and supporting controls. WQI verification is not a California approval, government certification, or health or safety certification.*

## How Verification Applies To Biological Matrices

Biological samples such as blood and tissue raise different questions for verification. Biological matrices present a different analytical problem than water or food. [Plastic particles have been detected in the blood of healthy donors](https://research.vu.nl/en/publications/discovery-and-quantification-of-plastic-particle-pollution-in-hum/), and [a 2025 study in *Nature Medicine* reported microplastic and nanoplastic accumulation in human brain, liver, and kidney tissue](https://www.nature.com/articles/s41591-024-03453-1), though [a subsequent *Nature Medicine* commentary raised concerns about contamination controls and validation in that study](https://www.nature.com/articles/s41591-025-04045-3).

A blood test that detects plastic particles establishes presence at the time of sampling. It cannot establish absence, quantify exposure over time, or support a health-outcome claim. Biological matrices remain research-grade rather than compliance-grade for microplastics.

## Frequently Asked Questions About WQI Verification

### How Long Does Verification Take?

Verification timelines depend on how complete the submitted dataset is and how quickly questions can be answered. The Wellness Quality Institute reviews existing laboratory data, method documentation, product scope, and supporting controls against WQI-CS-01. A complete submission moves more quickly than one that needs several clarification rounds.

### What Documentation Is Needed?

Companies should provide the laboratory report, the laboratory’s accreditation certificate and scope of accreditation, method documentation, chain-of-custody records, blank and spike-recovery results, and product scope information. The Wellness Quality Institute reviews what the company already holds. No new testing is required as part of the review, although the strength of existing data determines whether it meets the standard.

### What Happens If The Standard Is Not Met?

A Standard Not Met outcome remains private. It carries no public claim, no logo rights, and no registry listing, and it is never described as a failed product. The outcome may reflect insufficient data, inadequate controls, an unsupported method, or incomplete scope rather than any property of the product itself. The company may submit corrected or additional information for future review, so participating in the process carries no public downside risk.

### Does Verification Replace Legal Review?

Verification does not replace legal review. Companies remain responsible for ensuring all product, packaging, and marketing claims are accurate and properly substantiated. WQI verification is an independent review of a dataset against a defined standard. It is not legal, regulatory, or advertising-claims counsel.

### Can A Single Product’s Result Be Extended To A Product Line?

Verification applies only to the reviewed product, model or SKU, matrix, production or sampling period, tested particle-size range, polymer panel, and analytical method. No company-wide or product-line claim may be extended from a single dataset. Extending a single result beyond its registered scope is a prohibited claim under WQI-CS-01.

[Ask WQI whether your current dataset is ready for verification.](https://www.wellnessqualityinstitute.com/?utm_term=microplastics-lab-testing-verification-process&utm_campaign=ai_growth_agent)

## Conclusion: A Practical Checklist You Can Run Today

A laboratory report by itself is not a claim. The microplastics lab testing verification process determines whether existing data can support anything said publicly. Most brands have never run this check. The checklist below can be applied to any report currently in hand:

- Confirm the laboratory’s accreditation scope explicitly names the microplastics method and the matrix tested
- Confirm sampling methodology and field blanks are documented
- Confirm the analytical method’s validated particle-size range matches the range reported
- Confirm procedural blanks and spike recoveries are reported and acceptable
- Confirm counts are reported by size fraction, not as a single aggregate
- Confirm polymer identities are reported against a defined panel
- Confirm reporting limits, chain of custody, and stated limitations are present

If any item is missing, the data supports a narrower claim than the report suggests or may support no public claim at all.

As described earlier, WQI’s Plastic-Free Pathway Verification reviews existing lab data against defined criteria without running new tests or certifying products as plastic-free. The criteria align with the California State Water Board’s drinking-water microplastics reference framework. Verification shows that a company is on a verified pathway toward plastic-free standards, a claim that remains defensible because it does not overreach what current science can support. Organizations may choose to use this framework as a technical reference point.

For further reading on what laboratory data can and cannot prove, see [Microplastics Claim Verification: What Lab Data Can Prove](https://www.wellnessqualityinstitute.com/articles/microplastics-claim-verification-data/?utm_term=microplastics-lab-testing-verification-process&utm_campaign=ai_growth_agent), [Microplastics Testing Methodology And Verification Standards](https://www.wellnessqualityinstitute.com/articles/microplastics-testing-methodology-standards/?utm_term=microplastics-lab-testing-verification-process&utm_campaign=ai_growth_agent), [How To Know If Microplastics Lab Results Are Trustworthy](https://www.wellnessqualityinstitute.com/articles/microplastics-testing-verification-lab-results/?utm_term=microplastics-lab-testing-verification-process&utm_campaign=ai_growth_agent), and [What Microplastics Testing Proves And Where It Stops](https://www.wellnessqualityinstitute.com/articles/what-microplastics-testing-proves/?utm_term=microplastics-lab-testing-verification-process&utm_campaign=ai_growth_agent).

[Share your current lab report with WQI for an independent verification review.](https://www.wellnessqualityinstitute.com/?utm_term=microplastics-lab-testing-verification-process&utm_campaign=ai_growth_agent)

## Read Next

- [Microplastics Claim Verification: What Lab Data Can Prove](https://www.wellnessqualityinstitute.com/articles/microplastics-claim-verification-data/?utm_term=microplastics-lab-testing-verification-process&utm_campaign=ai_growth_agent)
- [What Microplastics Testing Proves and Where It Stops](https://www.wellnessqualityinstitute.com/articles/what-microplastics-testing-proves/?utm_term=microplastics-lab-testing-verification-process&utm_campaign=ai_growth_agent)
- [How to Verify Microplastics Lab Data for Defensible Claims](https://www.wellnessqualityinstitute.com/articles/third-party-lab-results-claims/?utm_term=microplastics-lab-testing-verification-process&utm_campaign=ai_growth_agent)
- [How to Turn Lab Data Into a Microplastics Verification Claim](https://www.wellnessqualityinstitute.com/articles/microplastics-verification-standard-claim/?utm_term=microplastics-lab-testing-verification-process&utm_campaign=ai_growth_agent)
- [How To Know If Microplastics Lab Results Are Trustworthy](https://www.wellnessqualityinstitute.com/articles/microplastics-testing-verification-lab-results/?utm_term=microplastics-lab-testing-verification-process&utm_campaign=ai_growth_agent)

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## Structured Data

### BlogPosting

- **Headline:** Microplastics Lab Testing: Does Your Data Support A Claim?
- **Description:** The Wellness Quality Institute helps you verify microplastics lab data before making public claims. Check your report today.
- **DateModified:** 2026-10-12T10:18:45.524Z
- **Image:** https://cdn.aigrowthmarketer.co/1784829434095-0fc8fbcf29fa.webp, https://cdn.aigrowthmarketer.co/1784829410323-fb401fc7b1e4.webp, https://cdn.aigrowthmarketer.co/1784829388732-c6255482b477.webp
- **InLanguage:** en-US
  **Person:**

  - **Name:** Scott Steveson
  - **JobTitle:** Specialist
  - **Description:** Scott Stevenson is part of the Wellness Quality Institute team, where he supports WQI’s work to advance product transparency, credible verification, and greater consumer trust. His background spans ethics and compliance, corporate trust, and responsible business, including experience with Ethisphere Institute and global companies navigating evolving standards and stakeholder expectations.
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    - **Name:** Wellness Quality Institute
    - **Url:** https://www.wellnessqualityinstitute.com/
  **Organization:**

  - **Name:** The Wellness Quality Institute
  - **Url:** https://wellnessqualityinstitute.com

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## Citations

- [How To Verify Plastic Contamination In Protein Powder](https://www.wellnessqualityinstitute.com/articles/verify-protein-powder-plastic-contamination)
- [Plastic Claim Substantiation: Evidence Before You Claim](https://www.wellnessqualityinstitute.com/articles/plastic-claim-substantiation-evidence-requirements)
- [How To Make Plastic Reduction Claims That Hold Up](https://www.wellnessqualityinstitute.com/articles/substantiate-clean-label-plastic-reduction)
- [Plastic Claim Substantiation: A US Compliance Guide](https://www.wellnessqualityinstitute.com/articles/plastic-claim-substantiation-compliance-guide)
- [Microplastics Verification Standards: A Complete Guide](https://www.wellnessqualityinstitute.com/articles/microplastics-verification-standards-guide)

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