Microplastics Testing For Retailers: Labs, Methods & Claims
The Wellness Quality Institute helps retailers choose labs, interpret results, and make honest microplastics claims. Start testing with confidence.
Read articleCompare plastic claim verification programs. The Wellness Quality Institute helps brands make defensible, regulation-ready plastic claims.

Written by: Scott Steveson, Specialist, Wellness Quality Institute
Consumer concern about microplastics keeps growing. Independent research has found plastic particles in tap water, bottled water, and human tissue. A 2018 peer-reviewed study by Kosuth, Mason, and Wattenberg in PLOS ONE found anthropogenic particles in 81% of 159 tap water samples drawn from five continents. A separate 2018 study led by Sherri Mason at the State University of New York at Fredonia, published in Frontiers in Chemistry, found microplastics in 93% of 259 bottled water samples across eleven brands, at roughly twice the particle concentration of tap water. The World Health Organization’s 2019 assessment found no indication of health risk at current levels on limited evidence and called for urgent additional research.

Regulators, retailers, and plaintiffs’ attorneys are responding to this concern. State laws, retailer policies, and class-action lawsuits now target plastic-related claims that lack solid proof. Plastic claims often move faster than the evidence behind them, and no single gold standard defines what every claim must show. Clear knowledge of the verification landscape, paired with a program that fits your specific claim, separates defensible positions from greenwashing risk.
A plastic claim verification program is a structured, independent review of a company’s evidence. That evidence can include supply chain documentation, laboratory data, or waste-recovery records. A reviewer with no commercial stake compares that evidence against a published standard.
Two broad categories exist, and the distinction guides claim selection.
Certification programs assess whether a product or process meets a defined threshold and issue a certificate when it does. For example, recycled-content certifications confirm that a stated percentage of material came from post-consumer or pre-consumer sources. The outcome is binary: certified or not.
Verification programs review evidence against a standard and issue a finding that reflects what the evidence supports. The Wellness Quality Institute operates in this category. Its Plastic-Free Pathway Verification (PFPV), governed by the standard WQI-CS-01, independently reviews a company’s existing laboratory dataset, testing methodology, product scope, and supporting controls. The Wellness Quality Institute does not run laboratory tests. It reviews data, and that separation supports its independence.
Both approaches convert raw evidence into a claim that can stand up to scrutiny. The right choice depends on the claim you want to make and the evidence you already have.
The table below outlines principal programs active in this space. It offers a starting framework, not a complete registry, and programs may evolve over time.
| Program | Focus | Claim Type | Regulatory Alignment |
|---|---|---|---|
| APR PCR Certification | Post-consumer recycled (PCR) content in plastic products, with full chain-of-custody and third-party audit | Recycled content percentage claims | Cited in California SB 54. Starting January 1, 2027, it is one option for companies using recycled content as virgin plastic source reduction credits in California. PCR content mandates also appear in Washington and New Jersey law. |
| UL 2809 | Recycled content validation covering pre- and post-consumer material | Recycled content claims | Supports compliance with recycled content regulations across multiple jurisdictions. |
| Verra Plastic Waste Reduction Standard | Plastic waste collection and recycling outcomes above baseline, issuing Plastic Credits (one credit equals one tonne of collected or recycled plastic) | Plastic credits, including Waste Collection Credits (WCCs) and Waste Recycling Credits (WRCs) | Can complement Extended Producer Responsibility (EPR) schemes. Credits represent additional collection or recycling beyond business-as-usual. |
| GreenCircle Certified | Third-party certification for a range of environmental claims, including recycled content | Recycled content and other sustainability claims | Helps companies address California SB 54 and SB 343 requirements. GreenCircle is also an APR-approved certification body for PCR audits. |
| rePurpose Global | Plastic action platform that funds verified waste recovery interventions and supports over 500 consumer brands | Plastic recovery and offset claims, including Verified Plastic Recovery and the Plastic Neutral badge | Supports packaging compliance and credible sustainability claims and is recognized by consumers in ecommerce contexts. |
| Wellness Quality Institute Plastic-Free Pathway Verification | Independent review of a company’s existing laboratory data on plastic and microplastic content against WQI-CS-01 | Verified progress toward plastic-free standards, framed as evidence-based progress | Criteria aligned with the California State Water Board’s drinking-water microplastics reference framework (technical reference only, not a California approval or endorsement). Available to US companies nationally. |
Certification signals a settled, confirmed state. When a recycled-content certification states that a product contains 30% post-consumer resin, auditors have checked that figure against a chain-of-custody standard. The certificate reflects a verified fact about material composition.
Verification reviews evidence against a standard and issues a finding that matches what the evidence supports. The finding describes what an independent reviewer concluded after examining a specific dataset, method, and product scope.
For recycled content, certification fits the claim. Material either came from post-consumer sources or it did not, and a chain-of-custody audit can confirm that path.
For plastic-free progress claims, certification does not fit current science. No laboratory today can confirm the complete absence of plastic across every particle size, polymer type, and production lot. The California State Water Board’s drinking-water definition reaches down to 1 nanometer, while the best validated analytical methods begin at 20 or 50 micrometers, which are thousands of times larger. A “certified plastic-free” claim would assert certainty about a range that instruments cannot yet measure.
The Wellness Quality Institute focuses on that gap. Its Plastic-Free Pathway Verification reviews what a company’s laboratory data supports within the tested particle-size range, for the reviewed polymer panel, and for the specific product and production period examined. The finding is a verified statement about reviewed evidence. That careful scope makes the claim defensible.
Several regulatory developments now shape how brands make plastic-related claims and what evidence they must hold.
California SB 54 and SB 343 address packaging recyclability and recycled content. APR PCR Certification is cited in SB 54, and starting January 1, 2027, it is one option for California companies using recycled content as virgin plastic source reduction credits. PCR content mandates also appear in Washington and New Jersey, with incentives in Oregon, Maine, and Colorado. These examples show how state-level requirements are evolving. Brands operating nationally should track rules in each relevant state.
The EU Green Claims Directive requires that environmental claims made in the EU be backed by independent, accredited verification before companies present them to consumers. While this applies directly to EU markets, US brands with European distribution or global supply chains already feel its influence on internal standards and retailer expectations.
The proposed Tracking Plastic Act, introduced in the US Senate, would promote standardized tracking and accountability for recycled plastic claims. The bill’s press release highlights congressional focus on the credibility gap in plastic claims. Regardless of the Act’s final outcome, regulators continue to move toward stricter substantiation requirements. Brands that build verification infrastructure now gain an advantage over those that wait for mandates.
California serves as a technical reference point for the Wellness Quality Institute’s criteria, not a geographic limit. The Wellness Quality Institute serves US companies nationally. Its alignment with California’s framework reflects the rigor of that standard rather than any California approval or endorsement.
Program selection follows directly from claim type. The first step is clarity about the claim and the evidence that supports it.
Three common claim types map to distinct program categories.
Recycled content claims such as “contains X% post-consumer recycled material” require chain-of-custody documentation that traces material from collection through processing to finished product. APR PCR Certification, UL 2809, and GreenCircle Certified serve this claim type. These programs audit supply chain records and material flow rather than laboratory data on plastic particle content.
Plastic credit or offset claims such as “we have funded recovery of X tonnes of plastic waste” require verified project activity and credit retirement. Verra’s Plastic Waste Reduction Standard and rePurpose Global operate in this space. Credits represent additional collection or recycling beyond what would have occurred without the project and relate to waste recovery rather than product content.
Plastic-free progress claims such as “our product has been independently reviewed for plastic and microplastic content” require laboratory data reviewed by an independent party against a defined standard. The Wellness Quality Institute’s Plastic-Free Pathway Verification serves this claim type for water and suitable simple-liquid products in Phase 1, where testing methods are most defensible.
When evaluating any program, use a practical checklist.
Every credible plastic-free progress claim starts with laboratory data. A raw laboratory report, however, does not automatically translate into a defensible market claim. It provides a number shaped by the instrument, the method, the polymers screened, and the production lot sampled.
A result that reads “no microplastics detected” means no particles were found above that instrument’s detection floor for the polymer types it screened in the lot it tested. The result does not address particles below that floor, polymer types outside the panel, or future production lots.

Independent review converts that bounded result into a claim a company can support. A third party with no stake in the outcome assesses whether the method suited the product matrix, whether contamination controls were adequate, whether the reporting limits meet a defined standard, and what the data can honestly support.
The Wellness Quality Institute’s review examines each factor that determines whether a lab result can support a claim. That review covers laboratory qualification, analytical method, product matrix, sampling approach, tested particle-size range, target polymer panel, reporting limits, blank results, spike recoveries (a quality-control check where a known amount of material is added to confirm the method is working), replicates, chain of custody, data recency, and product scope. Many companies discover through this process what their existing data proves and where it falls short.

The Wellness Quality Institute does not perform laboratory testing. Its independence from the testing it reviews supports the program’s credibility. A single assessment fee covers review, verification decision, and registry listing. There is no separate mark-license or registry fee. Laboratory testing is arranged and billed separately by a qualified independent laboratory.
The proposed Tracking Plastic Act illustrates where US policy is heading. It points toward standardized, independent substantiation for recycled plastic claims at a national level, building on the same logic already visible in state rules and retailer demands.
The Act’s legislative path remains uncertain, as with most proposed bills. The direction of travel, however, is clear. The OECD’s Global Plastics Outlook projects that global plastics production, use, and waste will rise approximately 70% by 2040 on current trajectories. As production volumes grow, scrutiny on claims about plastic content and reduction intensifies, scrutiny that early tap and bottled water findings helped ignite. Brands that build verification infrastructure before mandates arrive gain a strategic head start.
The Wellness Quality Institute’s criteria draw on the California State Water Board’s drinking-water microplastics reference framework, which currently offers one of the most stringent public technical references for testing. That alignment positions verified companies ahead of the regulatory curve.
The plastic claim verification landscape remains fragmented, with different programs serving different claim types. Recycled-content certifications, plastic credit programs, and independent lab-data review each rely on distinct forms of evidence. A mismatch between claim and program, or a claim made without independent review, now creates greenwashing exposure that is harder to defend.
The most practical starting point is a clear statement of the claim. Recycled content claims call for chain-of-custody certification. Plastic waste recovery claims call for a credit program. Progress toward plastic-free standards, supported by laboratory data on plastic and microplastic content, calls for independent review of that data.
For brands that already hold laboratory data, the gap between that data and a defensible market claim often feels smaller than expected in some areas and larger in others. Independent review clarifies both.
A certification confirms that a product or process meets a defined threshold. For example, a certification can confirm that a stated percentage of material came from post-consumer recycled sources, based on a chain-of-custody audit. The claim is binary. The standard is met or it is not, and the certificate reflects a confirmed fact about material composition or process.
A verification program reviews evidence against a standard and issues a finding that reflects what the evidence supports. This distinction matters most for plastic-free progress claims. As noted earlier, the gap between regulatory definitions and analytical limits makes “certified plastic-free” scientifically impossible. Verification describes what an independent reviewer found when examining a specific dataset, method, and product scope. That description is a defensible statement about reviewed evidence rather than a promise of total absence. The Wellness Quality Institute operates as a verification body for this reason.
The right program depends on your claim and your evidence. Recycled content claims, which state that a product contains a specific percentage of post-consumer or pre-consumer recycled material, require chain-of-custody documentation and fit programs such as APR PCR Certification, UL 2809, or GreenCircle Certified. Plastic credit or offset claims, which state that a brand has funded recovery of a specific volume of plastic waste, require verified project activity and credit retirement and fit programs such as Verra’s Plastic Waste Reduction Standard or rePurpose Global. Plastic-free progress claims, which state that a product’s plastic and microplastic content has been independently reviewed against a defined standard, require laboratory data reviewed by an independent party. The Wellness Quality Institute’s Plastic-Free Pathway Verification provides this review for water and suitable simple-liquid products. Matching your claim type to the appropriate program is essential, because using a recycled-content certification to support a plastic-free progress claim would not substantiate that claim and could create greenwashing risk.
The Wellness Quality Institute Plastic-Free Pathway Verification does not certify that a product contains zero plastic, microplastics, or nanoplastics. Current laboratory technology cannot confirm the complete absence of plastic across every particle size and polymer type. The best validated analytical methods begin at 20 or 50 micrometers, while the regulatory definition of microplastics reaches down to 1 nanometer. No instrument can currently see that full range. A verification confirms only what the reviewed dataset supports within the tested particle-size range, using an independently reviewed method, for the specific product and production period reviewed. The mark “WQI Plastic-Free Pathway Verified” signals that a company’s laboratory data has been independently reviewed against a defined standard and supports genuine progress toward plastic-free production. It does not describe the product as plastic-free. Verification applies only to the reviewed products, submitted datasets, tested ranges, polymer panels, production or sampling periods, and supporting controls. The Wellness Quality Institute verification is not a California approval, government certification, or health or safety certification.
A Standard Not Met outcome remains private. It carries no public claim, no logo rights, and no registry listing, and the product is not described as a failure. A Standard Not Met result often reflects the testing rather than the product itself. Common issues include insufficient data, an analytical method that does not fit the product matrix, inadequate contamination controls, or incomplete scope documentation. Companies may submit corrected or additional information for future review. Participation in the review process creates no public downside risk. That design encourages honest inquiry and supports the transparency the program aims to foster.
Regulatory requirements vary by claim type, jurisdiction, and market channel. For recycled content claims, state-level mandates are the most immediate factor. APR PCR Certification is cited in California’s SB 54, and PCR content mandates appear in laws in California, Washington, and New Jersey, with incentives in Oregon, Maine, and Colorado. Brands making recycled content claims in those markets should consider certifications aligned with those requirements. For plastic-free progress claims, no US federal standard currently governs substantiation. The proposed Tracking Plastic Act, however, signals congressional attention to the credibility gap, and the EU Green Claims Directive influences retailer expectations for brands with international distribution. Across all claim types, the FTC’s Green Guides require that environmental claims be truthful, not misleading, and substantiated. Independent verification against a published standard offers one of the most defensible ways to meet that baseline for any plastic-related claim.