# What “None Detected” Means in Microplastics Testing

> "None detected" doesn't mean zero plastics. The Wellness Quality Institute explains detection limits, blind spots & how to read lab results.

**Published:** 2026-10-11 | **Updated:** 2026-11-11 | **Author:** mihir
**URL:** https://www.wellnessqualityinstitute.com/articles/none-detected-microplastics-meaning
**Type:** post

**Categories:** Water Quality

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## Content

*Written by: Scott Steveson, Specialist, Wellness Quality Institute | Last updated: November 10, 2026*

## Key Takeaways

- “None detected” means no microplastics were found above the method’s detection limit for the specific polymers and sample tested. It does not confirm that zero microplastics are present in the product.
- Every “none detected” result is bounded by three factors: the instrument’s particle-size detection floor, the polymer panel screened, and the specific lot or batch tested.
- Standard microplastics methods cannot detect nanoplastics below 1 micrometer, so a “none detected” result says nothing about the smallest particles.
- A lab report alone does not become a defensible market claim. Independent review turns bounded data into verified, scope-locked statements.
- The Wellness Quality Institute provides independent verification of laboratory data through its Plastic-Free Pathway Verification program, helping brands communicate results accurately and defensibly.

[Learn About Plastic-Free Verification](https://www.wellnessqualityinstitute.com/?utm_term=none-detected-microplastics-meaning&utm_campaign=ai_growth_agent)

## Quick Answer: How To Read “None Detected” In Microplastics Testing

“None detected” means the laboratory found no microplastic particles above its method’s detection limit, for the polymer types it screened, in the specific sample it tested. The phrase does not confirm zero microplastics. The result is bounded by the instrument, the method, and the sample, not by the product as a whole.

![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.**

Every “none detected” result has three built-in boundaries. The first is the instrument’s detection floor, which is the smallest particle size the method can reliably identify. The second is the polymer panel, which is the specific plastic types the lab looked for. The third is the sample scope, which is the particular lot or batch that was tested. A result that says nothing about particles below 50 micrometers, polymers outside the tested list, or production runs other than the one sampled describes the test conditions, not the entire product.

As the MicroPlastics Research Desk put it in August 2026: “None detected” is a statement about an instrument, not a clean bill of health for your water. That framing is the most useful starting point for reading any microplastics lab report.

## Detection Limits: The Floor Beneath Every “None Detected” Result

A detection limit, sometimes called a limit of detection or LOD, is the smallest particle size and concentration that an instrument can reliably identify. A reporting limit, also called a limit of quantification or LOQ, is the threshold above which a lab will report a number with confidence. Below the reporting limit, a lab may report “none detected” even if particles are present, because the method cannot distinguish them from background noise with sufficient certainty.

This has a direct consequence. A lab can report “none detected” at 50 micrometers (µm) and say nothing at all about particles at 10 µm. Those smaller particles sit outside the method’s analytical window. They are not demonstrated absent. They are simply not examined.

![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.**

State water board methods show this clearly. One method, which uses infrared spectroscopy, is validated for particles greater than 50 µm through 5,000 µm. Another, which uses Raman spectroscopy, is validated for particles greater than 20 µm through 5,000 µm. A regulatory definition of microplastics in drinking water, however, reaches down to 1 nanometer, which is thousands of times smaller than either method’s validated floor. The 1–20 µm fraction is not validated under either method. A “none detected” result issued under either method is bounded by that method’s detection floor, not by the product.

Reporting limits are also laboratory-specific. [A 2026 study applying ISO 16094-2:2025 calculated its reporting limit as the mean procedural blank abundance plus three standard deviations, yielding 2.55 microplastic particles per liter](https://mdpi.com/2673-8929/5/2/124). That figure reflects that specific laboratory’s blank results, not a universal threshold. Any lab report worth relying on will state its numerical reporting limit, the blank procedure used to derive it, and the units. That number is often the most important thing on the page, and it is almost always in the smallest type.

[Talk To WQI About Your Lab Data](https://www.wellnessqualityinstitute.com/?utm_term=none-detected-microplastics-meaning&utm_campaign=ai_growth_agent)

## The Nanoplastic Blind Spot: What Current Tests Cannot See

Nanoplastics are plastic particles smaller than 1 micrometer, roughly a thousandth of a millimeter. They sit below the reliable reach of commercially available analytical methods. A “none detected” result on a microplastics test does not address nanoplastics at all.

[A 2026 study published in npj Clean Water found that up to 97% of microplastics in sampled natural waters fall between 1 and 20 µm](https://nature.com/articles/s41545-026-00612-4), a size range that methods validated only above 20 µm cannot reach. [The same study estimated that an analytical technique measuring only down to 20 µm misses between 73% and 97% of microplastics present.](https://nature.com/articles/s41545-026-00612-4) That gap exists before even reaching the nanoplastic domain.

[ISO 16094-2:2025, the international standard for vibrational spectroscopy methods in drinking water, specifies a lower size boundary of 1 µm](https://glstd.com/sist-en-iso-16094-2-2025). This means the standard explicitly excludes the nanoplastic domain below that size. A result reported under this standard cannot be interpreted as evidence that nanoplastics are absent.

None of this means nanoplastics are necessarily dangerous at current exposure levels. The World Health Organization’s 2019 assessment, [Microplastics in Drinking-Water](https://who.int), found no indication of health risk at current levels on limited evidence, while stressing that the conclusion rests on incomplete information and that more research is urgently needed. It does mean the result’s scope is narrower than most readers assume. No laboratory today can confirm the complete absence of plastic across every particle size.

## Polymer Panels: Which Plastics The Lab Actually Looked For

Size is only one boundary. Even within the sizes a method can see, a lab only finds the plastics it is looking for, which means specific polymer types and the particular plastic chemistries on its panel. A “none detected” result applies only to the polymers the lab actually tested. Common panels include polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), polystyrene (PS), polyvinyl chloride (PVC), nylon or polyamide (PA), polycarbonate (PC), and polymethyl methacrylate (PMMA). Panels vary by laboratory and by the analytical package ordered.

Eurofins Environment Testing Norway’s commercial panel covers 11 polymers, while other laboratories offer panels of 6 or fewer. A result can say “none detected” for the target panel while unidentified particles with no spectral match are reported separately or not reported. [Because spectral classification depends on the reference library, a “none detected” result is bounded by the polymers included, validated, and distinguishable in that library.](https://link.springer.com/article/10.1007/s13762-026-07533-2)

The practical question to ask before treating any “none detected” result as comprehensive is simple. Which polymers were in scope? A result that covers six common polymers says nothing about the many other polymer types that exist in the environment and in packaging.

## Sample Scope: Which Lot Was Tested And What The Result Covers

A microplastics result applies to the specific lot, sample, or production period tested. It does not apply to the whole brand or product line. Lot-to-lot variability is real. A clean result on one production run does not guarantee the next. Packaging conditions, filling equipment, and raw material sources can all shift between batches.

A lab report tells you what a laboratory found in a specific sample. It does not, by itself, define what that finding supports as a claim about the product, the brand, or future production. [As environmental scientist Marco Parolini noted in a 2026 opinion paper in Toxics: “Without this information, zero or low MP concentrations cannot be interpreted reliably, as they may reflect analytical limitations rather than the actual absence or scarcity of items.”](https://mdpi.com/2305-6304/14/9/783)

For brands, this creates a gap between holding data and being able to use it. Many companies have commissioned genuine, rigorous testing. They often lack a trusted way to communicate what that testing actually supports and where its limits sit.

[Turn Lab Data Into A Defensible Claim](https://www.wellnessqualityinstitute.com/?utm_term=none-detected-microplastics-meaning&utm_campaign=ai_growth_agent)

## Checklist: How To Read A “None Detected” Microplastics Lab Report

Readers can use a short checklist to make sense of any “none detected” result, regardless of the product or brand:

- What method was used, and what particle-size range does it cover?
- What was the detection limit and reporting limit, stated numerically?
- Which polymer types were screened?
- What sample or lot was tested, and when?
- Were procedural blanks and contamination controls run and reported?
- Was the laboratory accredited for this method and this sample matrix?
- Does the claim made about the result stay inside the tested scope?

A lab report that does not answer these questions does not clearly define what its “none detected” statement covers. A microplastics lab report that does not state its limit of detection or lower size cutoff should not be relied on. These are not obscure technical demands. They are simply the questions that help you understand what a result actually covers. For a broader look at how to evaluate bottled water testing, see [How To Test Bottled Water For Microplastics: Practical Guide](https://www.wellnessqualityinstitute.com/articles/test-bottled-water-microplastics/?utm_term=none-detected-microplastics-meaning&utm_campaign=ai_growth_agent).

## When “None Detected” Is Strong Evidence Versus A Low Bar

A “none detected” result is meaningful when the method suits the sample matrix, the reporting limits are adequate, blanks and contamination controls were run and reported, the polymer panel is comprehensive, and the claim made about the result stays within the tested scope. Under those conditions, the result tells you something real about what was found and what was not found above the method’s floor.

A “none detected” result is a low-bar outcome when the detection floor is high, such as 50 µm when smaller particles are the primary concern, the polymer panel is narrow, the sample is unrepresentative of the product line, or the result is stretched into a broader claim than the data supports. A result issued under a method validated only above 50 µm, covering four polymers, from a single production lot, does not support a claim that a product is free of microplastics.

The core distinction holds in both cases. Detection can establish presence. It cannot establish absence. A positive finding needs one particle. A negative claim needs certainty about everything the method did not and could not measure. [WQI’s existing explainer on what “None Detected” means in microplastics testing](https://www.wellnessqualityinstitute.com/articles/none-detected-microplastics-testing-meaning/?utm_term=none-detected-microplastics-meaning&utm_campaign=ai_growth_agent) covers the phrase-level definition. This guide goes deeper on the method mechanics behind it.

## How Independent Review Turns A Bounded Result Into A Defensible Claim

The checklist’s last question, about whether the claim stays inside the tested scope, is the one brands most often miss. Many companies already hold genuinely useful laboratory data. They have commissioned independent testing, spent real money on it, and acted on the results. A lab report alone, however, does not automatically become a defensible market claim. Self-reported results are often discounted as marketing, which can feel like a company grading its own homework, even when the underlying testing is rigorous.

The Wellness Quality Institute (WQI) is an independent verification body that reviews a company’s existing third-party laboratory data on plastic and microplastic content against a defined standard. WQI’s core program, Plastic-Free Pathway Verification, is governed by the standard WQI-CS-01, aligned with a state water board’s drinking-water microplastics reference framework. That framework is used only as a technical reference point, since it is one of the most stringent credible public references available. No state has authorized, approved, or endorsed WQI or its standard.

WQI does not run laboratory tests, and it does not certify that any product is free of plastic. Instead, it reviews the dataset, method, product scope, and supporting controls against defined criteria focused on particle size and polymer type. Because those criteria are fixed in advance, every review produces one of two outcomes. If the criteria are met, the company receives a verification decision, a scope-locked license to use the WQI logo, a public registry listing, and approved claim language. If the criteria are not met, the outcome stays private, is never described as a failed product, and can be resubmitted with updated information.

![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.**

Verification is locked to the reviewed product, dataset, tested particle-size range, polymer panel, and production period. No company-wide or product-line claim may be extended from a single dataset. A single assessment fee covers review, verification decision, and registry listing, with no separate mark-license or registry fee. Independent laboratory testing is arranged and billed separately by a qualified independent laboratory.

*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 state approval, government certification, or health or safety certification.*

## Common Misinterpretations Of “None Detected”

Several misreadings of “none detected” appear consistently across consumer and brand contexts. Each reflects a real gap between what the phrase sounds like and what it technically means:

- **Treating “none detected” as “zero microplastics.”** It means none found above the method’s detection floor. Particles below that floor were not examined.
- **Assuming the result covers nanoplastics.** Standard microplastics methods do not reach the nanoplastic range. A microplastics non-detect says nothing about particles below 1 µm.
- **Assuming the result covers every polymer.** It covers only the polymers in the screened panel. Polymers outside the panel were not tested.
- **Extending one product’s result to a whole brand or product line.** A result applies to the specific lot and sample tested. Lot-to-lot variability means one clean result does not guarantee the next.
- **Reading a lab report as a market claim.** A report and a defensible claim are different things. A report tells you what a laboratory found. It does not, by itself, establish what that finding supports as a public statement about the product.

For a related look at how label language can mislead in adjacent categories, see [BPA-Free Bottles Still Have Microplastics: What Labels Mean](https://www.wellnessqualityinstitute.com/articles/bpa-free-bottles-microplastics/?utm_term=none-detected-microplastics-meaning&utm_campaign=ai_growth_agent).

## Conclusion And Next Steps

“None detected” describes what the method could see under specific conditions. As the three boundaries above show, the result describes the test, not the product. The method behind the result matters as much as the result itself, and understanding that method turns a confusing phrase into a usable answer.

For consumers, the next steps are practical. Ask the checklist questions, look for independent review of any claim made about a “none detected” result, and treat absolute claims in either direction, such as “completely clean” or “definitely dangerous,” with healthy skepticism. The science is genuinely unsettled at the smaller particle sizes, and honest communication reflects that.

For brands holding laboratory data, the path from a bounded result to a claim that can be supported runs through independent review. A lab report that cost real money and reflects real diligence deserves to be used, and used accurately, within the scope the data actually supports. The Wellness Quality Institute’s Plastic-Free Pathway Verification exists to make that possible.

[Start Your Verification Inquiry](https://www.wellnessqualityinstitute.com/?utm_term=none-detected-microplastics-meaning&utm_campaign=ai_growth_agent)

## Frequently Asked Questions

### Does “None Detected” Mean There Are Zero Microplastics In The Product?

“None detected” means no microplastic particles were found above the method’s detection limit, for the polymer types screened, in the specific sample tested. Particles below the detection floor, outside the tested polymer panel, or from production lots other than the one sampled were not examined. No laboratory today can confirm the complete absence of plastic across every particle size, polymer type, and production lot. The phrase describes what the test could see under defined conditions.

### What Is The Difference Between A Detection Limit And A Reporting Limit?

A detection limit, or limit of detection, is the smallest particle size and concentration an instrument can reliably distinguish from background noise. A reporting limit, or limit of quantification, is the threshold above which a lab will report a number with sufficient confidence for it to be meaningful. Below the reporting limit, a result may be recorded as “none detected” even if some signal is present, because the method cannot distinguish it from laboratory background with enough certainty. Both values are specific to the laboratory and method, and both should be stated numerically in any credible lab report.

### Why Can’t Labs Detect Nanoplastics?

Nanoplastics, which are particles smaller than 1 micrometer, sit below the reliable reach of commercially available analytical methods. The infrared and Raman spectroscopy techniques used in routine microplastics testing are validated for particles above 20 or 50 micrometers, which are thousands of times larger than the nanoplastic range. Specialized research techniques can detect nanoplastics under controlled laboratory conditions. No standardized, validated method currently exists for routine commercial testing of nanoplastics in consumer products. This reflects a hard technical limit rather than a lack of diligence.

### What Does “None Detected” At 50 µm Mean For Smaller Particles?

“None detected” at 50 µm says nothing about smaller particles. A method validated above 50 µm cannot see anything below that threshold. Particles at 10 µm, 5 µm, or 1 µm sit outside the analytical window of the test. A “none detected” result at 50 µm is consistent with substantial numbers of smaller particles being present, because the method was not designed to find them. This is why the detection floor is often the most important number on a microplastics lab report.

### Which Polymers Are Typically Screened In A Microplastics Test?

Common panels include polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), polystyrene (PS), polyvinyl chloride (PVC), polyamide or nylon (PA), polycarbonate (PC), and polymethyl methacrylate (PMMA). Some laboratories offer broader panels of 11 or more polymer types, while others screen for as few as four or six. The panel varies by laboratory, by the analytical method used, and by the package ordered. A “none detected” result covers only the polymers in the screened panel and does not address polymer types that were not included.

### Does A “None Detected” Result Apply To The Whole Brand Or Just One Product?

A “none detected” result applies only to the specific lot, sample, or production period tested. A result from one production run does not guarantee the next. Packaging conditions, filling equipment, and raw material sources can all vary between batches, and lot-to-lot variability is a recognized feature of microplastics testing. Extending a single product’s result to a whole brand or product line goes beyond what the data supports, because the scope of the result is defined by the scope of the sample.

### What Questions Should I Ask About A “None Detected” Result?

The full checklist appears earlier in this guide. In short, ask what method and size range were used, what the detection and reporting limits are, which polymers were screened, which lot and date were tested, what controls were run, whether the lab was accredited for that method and sample type, and whether any marketing claim stays inside that tested scope.

### Can A Company Say “Plastic-Free” Based On A “None Detected” Result?

No laboratory today can confirm the complete absence of plastic across every particle size, polymer type, and production lot. This means no “none detected” result, however rigorous, can support an absolute “plastic-free” claim. The result is bounded by the method’s detection floor, the polymer panel, and the sample scope. What a company can do is describe what its data actually shows, within the tested range, for the screened polymers, in the reviewed production period, and have that description independently reviewed against a defined standard. The Wellness Quality Institute’s Plastic-Free Pathway Verification reviews a company’s existing laboratory data against defined criteria and, where the standard is met, issues approved claim language tied to the specific reviewed evidence. The program is named “Plastic-Free Pathway Verified” because the word “pathway” reflects a direction of travel that current science can support.

## What to Read Next

- [What "None Detected" Means in Microplastics Testing](https://www.wellnessqualityinstitute.com/articles/none-detected-microplastics-testing-meaning/)
- [What Microplastic Test Results Actually Mean](https://www.wellnessqualityinstitute.com/articles/what-microplastic-testing-actually-proves/)
- [Microplastics Detection Floor: What Lab Results Really Mean](https://www.wellnessqualityinstitute.com/articles/detection-floor-microplastics-analysis/)
- [What Microplastics Lab Reports Prove — And What They Don't](https://www.wellnessqualityinstitute.com/articles/what-microplastics-lab-reports-prove/)
- [How to Test for Microplastics: Methods, Limits & Labs](https://www.wellnessqualityinstitute.com/articles/microplastic-testing-methods/)

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## Citations

- [Nanoplastic Detection Validation: Gaps, Standards & Claims](https://www.wellnessqualityinstitute.com/articles/nanoplastics-detection-methods-validation)
- [Microplastics Standards Compliance: Rules, Status & Evidence](https://www.wellnessqualityinstitute.com/articles/california-microplastics-compliance-rules)
- [Microplastics in Bottled Water: 2024 PNAS Study Findings](https://www.wellnessqualityinstitute.com/articles/microplastics-bottled-water-study)
- [Microplastics vs. Nanoplastics: What You Need To Know](https://www.wellnessqualityinstitute.com/articles/nanoplastics-vs-microplastics)
- [Microplastics in Bottled Water: Which Part Is Responsible](https://www.wellnessqualityinstitute.com/articles/microplastics-sources-bottled-water)

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