The fleece is a non-woven fabric of cellulose staple fibres — viscose or lyocell — held together by a binder that can be anything from 20% to 60% of the material’s weight. FDA makes manufacturers specify its basis weight and porosity before a pouch can be sold. Yet the one study that measured pore size across real products found it did not predict how fast nicotine came out.
I came to this topic expecting a short answer and a shrug. The pouch is the bit you throw away; the interesting chemistry is inside it. That turns out to be wrong in an interesting way. The fleece is the most heavily specified part of a nicotine pouch in American law, the least described part on any brand’s website, and the subject of a genuine disagreement between two primary measurements that point in opposite directions.
Everything below comes from patents, regulations, regulator reviews and government reports. Where a figure is my arithmetic rather than a published number, I say so.
What the fleece is actually made of
The best single document is a patent on the material itself: EP 3 784 064 B1, “A packaging material and an oral pouched nicotine product”, proprietor Swedish Match North Europe AB. Its claim 1 is effectively a recipe:
“said packaging material being a saliva-permeable nonwoven material comprising carded fibres,” “50%-100% of said carded fibres being cellulose-based staple fibres, and” “0%-50% of said carded fibres being thermoplastic fibres” … “said packaging material further comprising a binder, said binder constituting 20%-60%” “of a total weight of said packaging material,” “said cellulose-based staple fibres having a linear density less than 1.7 decitex,” “and said packaging material having a basis weight above 30 g/m2.”
The thermoplastic component, where present, “may be one or more of PP, PLA, PET, PP/PE, PLA/co-PLA”. An earlier Swedish Match patent, EP 3 087 852 A1, gives the industry’s generic description and the comparison everyone reaches for: “The pouch material is typically made of a nonwoven fleece (soft fabric) material, such as viscose” and “The viscose nonwoven material normally used for pouched smokeless tobacco products” “is similar to the fabric used in tea bags.”
Suppliers tell the same story from the other side of the invoice. Nonwovenn Ltd — a non-woven manufacturer, not a tobacco company — writes in US 12,601,093 B2 that “Lyocell is used in the examples below, but other materials known in the art such as viscose are also suitable.”
The only independent measurement of what the material is comes from the Danish environmental regulator. In Miljøprojekt 2267, “Nikotinposer – indhold og miljøkonsekvenser” (Miljøstyrelsen, 2024), researchers ran FTIR spectroscopy on pouches from several makers: “Nikotinposer er typisk fremstillet af en form for semi-syntetisk cellulose (såsom viskose fleece)” — nicotine pouches are typically made of a form of semi-synthetic cellulose, such as viscose fleece. Comparing spectra, they found that “Det spektrum, som har størst lighed med nikotinposer ud af de undersøgte materialer, er cigaretfiltre” — of the materials examined, the spectrum most similar to nicotine pouches is cigarette filters.
That last line is worth handling carefully. The report says the pouch spectrum most resembles cellulose acetate. It does not say the fleece is cellulose acetate, and I am not going to write that it is.
The binder is the half of the material nobody mentions
Read claim 1 again: up to 60% of the fleece by weight can be binder. The patent’s preferred range is “25%-55%”, “more preferably 30%-50%”, “most preferably 35%-45%”. The conventional snus material the patent uses as its control “comprises 40 wt% binder”. So roughly two-fifths of the fabric in your lip is not fibre at all.
What is it? EP 3 784 064 B1 says the binder “may e.g. be classified as an emulsion of one or several vinyl polymers/co-polymers” formed from monomers including “vinyl acetate, ethylene/vinyl acetate copolymer,” “acrylic acid, methyl acrylate, butyl acrylate”. EP 3 087 852 A1 adds the reason it is there at all: “When a welding method is used, a binder may be used in the pouch material to facilitate sealing of the material.” The binder is what lets the pouch be heat-sealed shut.
Exactly one consumer page I could find admits the binder exists. ZYN’s UK help centre says: “The sachet paper contains a binder that is not completely biodegradable and therefore cannot be recycled.” (uk.zyn.com)
Manufacturers are not keen on it either, though their complaint is not safety. R.J. Reynolds, in US 10,959,456 B2, lists the problems with conventional acrylic binders: they “are costly to apply to pouches” and “inhibit biodegradability of the discarded pouch”, and “a heat sealable binder coating can produce an undesirable slimy mouth feel when wetted by saliva.” There is also, it notes, “a potential for retardation of flavor transfer due to the presence of a binder coating.” Swedish Match has a binder-free variant too, in WO 2020/169514 A1, which it says “may be experienced as less slippery in the mouth as compared to commonly used packaging materials” — at the cost of “a potentially negative impact on the seal strength, especially over time”.
That is the most honest sentence on mouthfeel in the whole literature, and it comes from a patent rather than a brand.
What a fleece is specified by
Four numbers do most of the work: basis weight (grams per square metre), air permeability, pore size and seal strength. EP 3 784 064 B1 publishes all four for its own materials and for the commercial snus material it benchmarks against, which makes it the only place you can see the old and new specifications side by side.
| Property | Conventional snus pouch material (the patent’s “Reference”) | The patent’s newer materials | Other published points of reference |
|---|---|---|---|
| Fibre | “100% of the fibres are viscose fibres having a linear density of 1.7 decitex.” | 0.9 dtex viscose, 0–42% polypropylene by fibre count | Lyocell or viscose (Nonwovenn); PLA, PET, PP/PE permitted |
| Basis weight | “It has a basis weight of 29 g/m2.” | 38 g/m²; claim floor “above 30 g/m2”, preferred ceiling 40–45 g/m² | Tea-bag web ≈16.5 g/m² (Philip Morris USA, US 9,044,049 B2); 25–35 g/m² (Nonwovenn) |
| Binder | “The sample also comprises 40 wt% binder.” | 20–60% of total weight; preferred 35–45% | Binder-free variant exists (WO 2020/169514 A1) |
| Air permeability (EDANA WSP070.1.R3(12)) | 4500 ± 195 l/m²/s | 1828–2822 l/m²/s; claim limit “≤ 4000 l/m2/s” | Nonwovenn: “Air permeability >1700 l/m2/s” |
| Median pore size | 326 ± 30.3 µm² | 60–136 µm²; claim limit “≤ 300 µm2” | BAT measured aperture diameters of 63–224 µm — a different quantity |
| Ultrasonic seal strength | 0.16 ± 0.03 N/mm | 0.30–0.44 N/mm | Nonwovenn: “Heat sealability >1000 g” |
| Thickness | not stated in the patent | not stated in the patent | 0.15–0.25 mm (Nonwovenn); 0.1–0.15 mm (R.J. Reynolds) |
One trap in that table, because I nearly fell into it: Swedish Match reports median pore size as an area in µm², while BAT and the published product measurements report pore or aperture diameter in µm. 326 µm² and 326 µm are not the same thing and cannot be compared.
And the tea-bag comparison, which the industry itself makes, is directionally right and numerically loose: pouch fleece runs roughly twice the grammage of the tea-bag web in Philip Morris USA’s patent.
Does the fleece change the hit? Two measurements, opposite answers
This is the part I found genuinely interesting, because the primary record contradicts itself in a way that is easy to resolve once you see what each side measured.
The case that it does. British American Tobacco’s US 2014/0026912 A1, “Fleece for Smokeless Tobacco”, deliberately punches apertures into viscose fleece and measures what happens. Using Franz diffusion cells — “The solvent used was water at ambient temperature” and “The spectrophotometer was set at 260 nm” — it reports that “the average absorbance reading of the apertured fleece is 3.73 at 30 seconds” “whereas the average absorbance reading of the standard fleece is 1.82 at 30 seconds”, and that the apertured pouch “has a release rate that is 105% faster than a snus pouch formed from the standard fleece”.
Three caveats travel with that number, and all three are visible in the document. The apertures are mechanically made, not naturally occurring. The measurement is absorbance of tobacco constituents at 260 nm, not nicotine — the word “nicotine” does not appear anywhere in the patent’s own text. And it is a one-gram snus pouch sitting in water on a bench, not in anybody’s mouth.
The case that it doesn’t. In January 2026, Platt and colleagues published measurements on seven commercial pouch brands in Scientific Reports, imaging the emptied pouch material by confocal microscopy. The pore sizes differ substantially: “Volt having the largest pore size of 104.812 μm”; “Rogue and Loop have similar pore size of 73.428 μm and 74.777 μm”; “Zyn and Dryft were next with 67.951 μm and 52.730 μm”; “The smallest pore size was observed for on! and Velo with 49.219 μm and 49.918 μm.”
And then, flatly: “These differences in pore size did not correlate with the dissolution rates” “where Rogue and Loop have similar pouch material pore size, but very different nicotine dissolution release profiles.” “In addition, on!, Zyn, and Rogue had different pore sizes yet equivalent nicotine dissolution release profiles.” The release differences are large — “over 88% of nicotine was released from on!, Zyn, Velo, Dryft, and Volt nicotine pouches” within an hour, against “only 72% and 38% of nicotine was released from Rogue and Loop pouches, respectively” — and the authors attribute them to the filler inside rather than the fabric outside.
That study was “funded by Altria Client Services LLC, an affiliate of Helix Innovations LLC, the manufacturer of on! nicotine pouches”, and all eight authors were Altria employees at the time. Two of the seven products tested belong to the funder’s corporate family, including the fastest-releasing one. I would not discard the finding on that basis — the measurements are published and the disclosure is complete — but anyone reading “the pouch material does not matter” should know who paid for it.
My own reading, and I will label it as mine: fleece porosity can be engineered to change release, because BAT engineered it and measured the change. The porosity differences that happen to exist between products on a shelf have not been shown to change nicotine release at all. Those are compatible statements, and together they are a better answer than either headline.
Where the fleece demonstrably does matter: dust and seals
If you want to see what fleece specification really buys a manufacturer, look at what Swedish Match measured when it changed the material. EP 3 784 064 B1’s problem statement is not release but leakage: the commonly used material “may often suffer from having a seal strength of the pouched product” “being less than desirable, especially when exposed to aggressive flavours”, and loose powder means “the remnants are negative for the working environment”.
The payoff is dramatic. Powder leakage through the material fell from 10% (4000 mg) for the reference to as little as 0.01% (4 mg). Leakage from finished pouches fell from 210 ± 49 mg to zero. And the basis-weight series is the cleanest demonstration in the document: at 15% polypropylene content, 30 g/m² leaked 12 mg, 34 g/m² leaked 2 mg, and 38 g/m² leaked nothing.
So grammage is, above all, a dust specification. That is a less romantic answer than “it changes the hit”, and it is the one with the data behind it.
Softness is measurable too. BAT reports bending rigidity of 9.7 µNm for its apertured fleece against 17.2 µNm for standard fleece in the same direction, and Nonwovenn specifies “Surface roughness RZ < 70 μm”, noting that “Surface roughness may provide a measurable parameter that is indicative of mouthfeel.”
Who regulates the fleece, and who doesn’t
Here is the surprise. The United States regulates this material by name, in the rule governing premarket applications. 21 CFR 1114.7, Table 3, requires applicants for a portioned smokeless tobacco product to “Provide target specification with upper and lower range limits for:” — among other things — “Pouch material basis weight (g/m2) (if applicable).” and “Pouch material porosity (permeability) (CU or L/m2/s) (if applicable).” Both reappear in the test-data column, alongside “Nicotine dissolution rate (%/min).” — which, notably, carries no “if applicable” qualifier at all.
And FDA does check. Its review of Helix’s on! PLUS products records that “the applicant provided test data for portion mass, pouch material basis weight, and pouch” “material porosity that are within acceptable range limits for all new products.”
What FDA does not publish is what the material is. In its review of the ZYN products, the composition is redacted as confidential commercial information — the pouches “are composed of (b) (4)”. The entire public toxicological statement about the material is one clause: “the pouch material itself is unlikely to produce any adverse health effects in consumers.”
That sentence has since been contested from inside the agency. In a public comment filed to docket FDA-2025-N-0835 on 1 March 2026, Christy Leppanen, who identifies herself as a former CTP toxicologist assigned to review those products, wrote: “One was that we did not know the materials that constituted the pouch that users put in their mouths, something we unequivocally were required to know and consider before the agency granted marketing orders.” and “We could have and should have asked the applicant, but we did not.” That is her account in a federal docket, not a finding; FDA has not responded to it in the docket.
Outside the US, the picture is thinner than you would guess:
- Sweden touches the material once, by reference. LIVSFS 2024:2 § 11 says only that “Materials and articles that come into contact with snus, snus-like” “products and chewing tobacco shall meet the requirements for the composition and” “properties of materials and articles intended to come into contact with food.” The words “pouch”, “portion” and “non-woven” do not appear in the regulation at all.
- The EU catches it with a general duty and nothing more. Regulation (EC) No 1935/2004, Article 3, requires that food-contact materials “do not transfer their constituents to food in quantities which could:” “(a) endanger human health”. Its Annex I lists “Regenerated cellulose”, “Textiles” and “Paper and board” as groups that may be covered by specific measures. The one specific measure for regenerated cellulose, Directive 2007/42/EC, applies only to “a thin sheet material obtained from a refined cellulose” — film, not fabric. It does not reach a non-woven.
- GOTHIATEK, the industry’s flagship voluntary standard, sets fifteen numeric limits and none of them concerns the pouch. The material is not mentioned on the standard’s page at all.
- Germany’s BfR states its own scope plainly in Opinion 023/2022: “This health risk assessment from BfR focuses only on the use of nicotine in such pouches.”
What nobody has published
Four clean gaps, each of which I went looking for and did not find:
Nothing measures what comes out of the fleece. I could find no published study that separates the emptied pouch material and reports its extractables — residual binder monomers, metals, anything. Platt’s team rinsed emptied pouch material with deionised water, but only to photograph it.
Nobody publishes a sealing temperature. Seven patents give binder and fibre melting points — “110-260°C” in one, under 230 °C in another — and not one gives the temperature at which a pouch is actually sealed.
Nothing says the fleece is bleached. I checked eleven patents, two FDA reviews, the Swedish and German regulations, GOTHIATEK and the manufacturers’ own pages. No document states that pouch fleece is bleached, gives a whiteness value, or distinguishes bleached from unbleached material. The only published mechanism for changing a pouch’s colour runs the other way: Altria’s WO 2014/144013 A1 describes polypropylene fibres that “include 8% brown colorant”.
Nobody has measured drip. Not one of the documents above connects fleece properties to how wet a pouch runs. If you read that a tighter fleece drips less, that is a plausible mechanism, not a measurement.
On the environmental side there is one firm, uncomfortable finding and one honest absence. The Danish EPA states that “Der kan på nuværende tidspunkt ikke identificeres studier af nedbrydeligheden af nikotinposer” — no studies of the degradability of nicotine pouches can currently be identified — and reasons by analogy from cigarette filters that the material will degrade slowly, and that “Dette indbefatter også dannelsen af mikroplast gennem denne nedbrydningsproces” (this includes the formation of microplastics through that degradation process). FDA’s own programmatic environmental assessment for this product category, dated 10 March 2026, says that “Many products in this category contain synthetic polymers and plastic materials,” “some of which are non-biodegradable or only slowly biodegradable” — and then excludes the question from its own scope: the assessment “does not address the potential effects of plastics and microplastics from the pouch” “materials.”
What the makers call it
The vocabulary tells you how little is volunteered.
| Brand | Its own published term | Composition stated? |
|---|---|---|
| SNØ | “viscose fleece” | Yes — the only brand page naming the fibre |
| Swedish Match (for Onico) | “material in the portion pouches” | Yes — “similar to that used in tea bags and essentially consists of cellulose fibers. The fibers are held together by a binding agent.” |
| Swedish Match (snus production) | “cellulose fiber tube” | Partly |
| ZYN UK | “sachet paper” | Binder only, and that it is not fully biodegradable |
| Pablo | “the pouch itself” | “made from plant fibres, specially designed to release nicotine while feeling comfortable under your lip” |
| Nordic Spirit | “the softer material” | No |
| ZYN US, VELO US | no term at all | No — neither page describes the wrapper |
The technical words — non-woven, carded, staple fibre, basis weight, grammage, air permeability — appear in patents, in FDA’s regulation, in FDA’s reviews and in a Danish government report. They appear on no consumer page I opened.
Frequently asked questions
Is a nicotine pouch basically a tea bag?
Swedish Match’s own patent says the material “is similar to the fabric used in tea bags”, so the analogy is the industry’s, not the internet’s. But pouch fleece is heavier: around 29–40 g/m² against about 16.5 g/m² for the tea-bag web in Philip Morris USA’s patent. Roughly twice the fabric.
Is the fleece plastic?
Legally unresolved, and the ambiguity is real. Regulation (EU) No 10/2011 on plastics never mentions cellulose, viscose or non-wovens; whether a regenerated-cellulose fibre counts as “plastic” turns on whether it is a natural macromolecule that has been “chemical[ly] modif[ied]”. The EU single-use plastics directive has the same pivot. A supplier’s own patent notes in passing that “‘fibrous PBS’ is defined as a single use plastic by EU directive.” I could not retrieve the Commission’s guidance on where viscose falls, so I am not going to state an answer.
Does a white pouch use different fleece from an original snus portion?
No published evidence says so. In fact the material family is shared: Swedish Match’s tobacco-free pouch patent benchmarks against “a packaging material commonly used for commercial snuff products”. The white-versus-original distinction lives in whether the pouch is sprayed with water after it is formed, not in the fabric. We covered that in white portion vs original portion snus.
Can I recycle the pouch?
ZYN’s UK help centre says no, and gives the reason: the binder “is not completely biodegradable and therefore cannot be recycled.” No regulator has published a degradability measurement for this material.
Does a finer, tighter fleece mean a weaker pouch?
Not on the published evidence. The seven-brand measurement found pore size uncorrelated with nicotine release. What a tighter fleece reliably buys is less powder leakage and a stronger seal.
Sources
- EP 3 784 064 B1, “A packaging material and an oral pouched nicotine product”, Swedish Match North Europe AB — EPO publication server. Claim 1, binder ranges, Reference material, air permeability, pore size, seal strength and leakage tables.
- EP 3 087 852 A1 and WO 2020/169514 A1, Swedish Match — generic fleece description, binder and welding, binder-free variant.
- US 2014/0026912 A1, “Fleece for Smokeless Tobacco”, British American Tobacco (Investments) Ltd — Franz cell method, absorbance figures, 105% release-rate claim, bending rigidity.
- US 10,959,456 B2, R.J. Reynolds Tobacco Co — binder-fibre pouch, slimy mouthfeel, biodegradability.
- US 12,601,093 B2, Nonwovenn Ltd — lyocell, basis weight, air permeability, thickness, wet strength, surface roughness.
- US 9,044,049 B2, Philip Morris USA Inc — tea-bag web basis weight and wet tensile strength.
- Platt SP et al., “Dissolution and physical characterization of oral nicotine pouch products”, Scientific Reports (2026) — pore sizes, the non-correlation finding, dissolution percentages. Funded by Altria Client Services LLC; all authors Altria employees at the time of the study.
- 21 CFR 1114.7, Table 3 to paragraph (i)(2)(ii) — required design parameters for portioned smokeless tobacco products.
- FDA, Technical Project Lead reviews for ZYN and Helix on! PLUS.
- FDA, Programmatic Environmental Assessment for nicotine pouches and related products, 10 March 2026.
- Christy Leppanen, public comment FDA-2025-N-0835-0182, received 1 March 2026.
- Miljøstyrelsen (Danish EPA), “Nikotinposer – indhold og miljøkonsekvenser”, Miljøprojekt 2267, 2024, ISBN 978-87-7038-614-2. Government-funded.
- Livsmedelsverket, LIVSFS 2024:2, English text as notified to the European Commission (TRIS 23913).
- Regulation (EC) No 1935/2004 and Commission Directive 2007/42/EC.
- BfR, Opinion 023/2022, “Health risk assessment of nicotine pouches”, 7 October 2022.
- Manufacturer pages: ZYN UK help centre, ZYN US FAQ, Swedish Match FAQ, SNØ, Pablo, Nordic Spirit FAQ, VELO US FAQ.
Related reading on this site: nicotine pouches explained, dry vs moist nicotine pouches, pouch pH and why it changes the hit, and nicotine content in snus vs nicotine pouches, and the master ranking.