Humectants: the ingredient snus needs and most pouches don’t
A humectant — in practice propylene glycol or glycerol — is added to hold water in a product and to lower its water activity so microbes cannot grow. Snus needs one, because it is roughly half water. Most nicotine pouches on sale today do not: the only cross-brand measurements put four of seven products under 4.5% moisture, and the three brands that publish an ingredient list declare no humectant at all.
I set out to write this page as “why pouches stay moist” and the measurements broke the premise. What survives is a better question: if a pouch contains almost no water, why does it not spoil, and what is the ingredient doing in the products that do use it?
The answer turns on a distinction that almost nothing written for consumers makes — between how much water is in a thing and how much of that water is chemically available. For the water in snus specifically, our page on snus moisture levels has the numbers; for the dry-versus-moist classification in pouches, see dry vs moist nicotine pouches; for the full ingredient inventory, what is inside a nicotine pouch besides nicotine.
“Humectant” is a federal regulatory category, not marketing language
The United States Code of Federal Regulations defines the term, in the list of functional food-ingredient classes at 21 CFR 170.3(o)(16):
Humectants: Hygroscopic substances incorporated in food to promote retention of moisture, including moisture-retention agents and antidusting agents.
And the same body of regulation names propylene glycol as one. 21 CFR 184.1666, the section affirming propylene glycol as generally recognised as safe, lists it as being used as humectant as defined in
that very paragraph, and notes drily that It does not occur in nature.
Worth noticing what that definition does not say: it covers moisture retention and nothing else. The second function, the one that matters for shelf life, appears only in the industry’s own technical accounts.
The manufacturer’s own two-purpose account
The clearest statement comes from Swedish Match’s own description of its GothiaTek standard, published in Harm Reduction Journal in 2011. Its competing-interests section reads All authors are or have been employees of Swedish Match AB.
— there is no funding statement in the paper at all. Treat it as a manufacturer document in a peer-reviewed wrapper, which is what it is.
Its composition sentence: The components of Swedish snus are a blend of air and/or sun-cured tobacco, water, sodium chloride, sodium carbonate, humectants, and flavoring agents.
And The water content is around 45-60%.
Then the sentence this page exists for:
Humectants, such as, propylene glycol and glycerol, serve two purposes; to retain moisture, and lower the water activity.
The stray comma after “such as” is in the original. The same paper divides the labour among three additives explicitly: Sodium chloride adds flavor and prevents microbial activity.
, sodium carbonate handles pH, and the historical account credits the use of humectants to lower the water activity in the finished product
, because Products with a high water activity tend to support more microorganisms.
I had been working from a note that salt does not lower water activity and that humectants do. That is wrong, and the correction comes from the same company’s own patent file. European patent application EP 3 192 380 A1, filed by Swedish Match North Europe AB, gives both roles in adjacent paragraphs. Paragraph [0095]:
Salt, such as sodium chloride lowers the water activity of the products, thus preventing microorganisms from growing.
And [0097]:
Humectants, such as propylene glycol or glycerol, may also be added to protect the product from drying out and may also have a preservative effect since the water activity of the product will be lowered, thereby preventing microorganisms from growing.
Both lower water activity, which is what any dissolved solute does; the review simply does not spell out the mechanism for salt. That same paragraph carries the only loading figure the company has published: from about 5 to about 15% w/w based on dry weight of the tobacco composition
.
Water content and water activity are not the same quantity
This is the distinction the whole subject rests on, and American food law states it precisely. 21 CFR 117.3 defines water activity as a quantity that is a measure of the free moisture in a food and is the quotient of the water vapor pressure of the substance divided by the vapor pressure of pure water at the same temperature
.
The reason it matters, rather than total water, is set out in FDA’s own inspection technical guide on the subject, a document dated 1984 and still published:
The bacterial cell can only transfer nutrients in and waste materials out through the cell wall. The materials, therefore, must be in soluble form to permeate the cell wall. A portion of the total water content present in food is strongly bound to specific sites and does not act as a solvent.
A microbe cannot drink bound water. The thresholds, from the same guide: Most foods have a water activity above 0.95 and that will provide sufficient moisture to support the growth of bacteria, yeasts, and mold.
and If the water activity of food is controlled to 0.85 or less in the finished product, it is not subject to the regulations of 21 CFR Parts 108, 113, and 114.
One caveat before anyone over-reads that: this is food law, and a nicotine pouch is not a food. I am borrowing the mechanism and the measurement convention, not claiming the regulation applies.
The measured table, and why the pouch category is mostly dry
There is exactly one cross-brand dataset with both moisture and water activity in it: a dissolution and physical-characterisation study of seven pouch products. Its funding statement is important — This research was funded by Altria Client Services LLC, an affiliate of Helix Innovations LLC, the manufacturer of on! nicotine pouches
, with a further disclosed agreement involving the maker of one of the other products tested. Water activity was measured Water activity in the nicotine pouch products was measured using an Aqualab TDL (Tuneable Diode Laser) Water Activity Meter
, in triplicate.
| Product | Moisture (% oven volatiles) | Water activity (aw) | pH |
|---|---|---|---|
| ZYN | 3.52 ± 0.08 | 0.56 | 7.62 |
| Dryft | 3.71 ± 0.15 | 0.56 | 8.31 |
| on! | 4.48 ± 0.20 | 0.57 | 8.62 |
| Velo | 6.62 ± 0.23 | 0.56 | 8.98 |
| Rogue | 14.70 ± 0.14 | 0.65 | 7.43 |
| Loop | 26.64 ± 0.84 | 0.87 | 8.62 |
| Volt | 37.18 ± 1.80 | 0.92 | 8.47 |
| Swedish snus, for comparison | 45–60% water | not published | about 8.5 target |
Four of the seven sit under 4.5%. Not one reaches the 40% that the industry’s own convention calls moist. And look at the ZYN row: water activity 0.56, comfortably below the floor where microbes grow, reached with 3.5% moisture and no declared humectant. The dry pouches are not preserved by a clever additive holding their water hostage. They are preserved by scarcely having any water.
“Moisture” on a pouch is not water, and the error has been quantified
There is a trap in that table, and the people who found it were measuring tobacco. A 70-product survey of American and Swedish smokeless products — funded by British American Tobacco, with three authors BAT employees and one a paid BAT consultant — compared the standard oven method against a true water assay:
In particular the oven method, commonly used to determine moisture in tobacco, gave significantly higher values than the Karl Fischer water method when propylene glycol was present.
And they put a number on it: Using the data obtained in this study across all STP categories and comparing the highest oven method with Karl Fischer measurements suggests an average error of 10–15% would arise.
The oven drives off the humectant along with the water and counts both. So any product that does use propylene glycol has its moisture figure inflated by roughly a tenth to a seventh — which means the dry pouches above are, if anything, drier than printed, and the wet ones contain less water than their number suggests. The industry convention of “under 10% is dry, over 40% is moist” is written about water content; almost every published figure is oven volatiles. They are not the same quantity.
Who declares a humectant, and who declares nothing
The systematic answer comes from a label survey of around fifty pouch products carried out by the German Federal Institute for Risk Assessment — notable in this field for having the cleanest funding of anything available. Its conflict statement reads The authors declare that they have no conflict of interest.
Their count of declared humectants:
Propylene glycol (E1520), 25; sodium alginate (E401), 11; glycerol (E422), 10; undefined humectant, 7
And in their summary of what dominates these labels: Most abundant ingredient categories with more than 40 counts were sweeteners, aroma additives, humectants (mostly propylene glycol)
.
So humectants are commonplace across the category as a whole. But go to the three brands whose published ingredient statements I could actually read, and they vanish. I searched each page for glycerol, glycerin, propylene and humectant, and all four terms return zero on all three.
ZYN publishes the most detail: In addition to nicotine salt, ZYN contains only food-grade ingredients. These include a granulation agent, fillers, pH balancers, sweeteners and flavorings.
— and then itemises a granulation agent, cellulose and maltitol fillers, gum arabic, sodium carbonate and bicarbonate, and acesulfame K. No humectant, and no water either.
Velo’s wording is looser and the difference matters: VELO pouches are made from high-quality ingredients, including water, plant-based materials, flavouring, sweeteners and pharmaceutical grade nicotine, all prepacked in a small pouch.
The word including makes that a non-exhaustive list. It is an absence of declaration, not a denial of use.
Rogue publishes no list at all, only a description: Nicotine polacrilex is combined with flavors and other food grade ingredients resulting in a flavorful, quality pouch.
Several other brands have no reachable ingredient page at all — parked domains, retailer redirects, dead hosts. For those I can report neither presence nor absence.
How much is in there? Only tobacco has been measured
No per-pouch milligram or percentage figure for propylene glycol or glycerol in a tobacco-free nicotine pouch exists in the published literature. The German survey counted declarations without quantifying them. The Altria-funded study measured water activity and moisture but not humectant content. The only quantitative loadings in existence are for tobacco products, from the BAT survey:
They were used at the highest levels in L Snus (mean combined glycerol and propylene glycol contents of 6.5%), and at lower levels in CT (3.5%), P Snus (2.7%) and Plug (2.3%).
With a striking split between the two humectants by format: There were significantly higher levels of glycerol in the L Snus compared with the P Snus (3.0% vs 0.05%), potentially due to manufacturing factors.
Loose snus is glycerol-heavy; portion snus essentially is not.
Three figures circulate for snus and they are on three different bases: the BAT survey’s 2.7% for portion snus is as-sold; the Swedish Match patent’s 5 to 15% is on the dry weight of the tobacco composition; and a figure of 1.5 to 3.5% that appears in the literature is BAT quoting someone else’s review rather than measuring. Any comparison has to say which basis it is on.
Is it safe to put in your mouth? The oral data is old, large and reassuring
I will not make a safety claim about any nicotine product. The humectants themselves, though, are ordinary food substances with a long regulatory record, and it is worth separating them from the rest of the pouch.
The World Health Organization’s expert committee on food additives set an acceptable daily intake for propylene glycol in 1973 of 0 to 25 mg/kg bw.
, having concluded that Conversion to lactic acid has been shown to be the normal metabolic pathway.
For glycerol, in 1976, the committee’s evaluation was simply ADI for man not specified.
— the category used for substances where no numerical limit is thought necessary. The human study it rested on is remarkable:
Fourteen (10 male, 4 female) graduate students ingested 110 g of 95% glycerol in 3 divided doses with their food daily for a period of 50 days.
And: No adverse effects were reported (Johnson, 1933).
A hundred and ten grams a day, for fifty days, against a few milligrams in a pouch.
The American status is worth getting precisely right rather than waving at “FDA approved”, which would be wrong in two directions. Propylene glycol is affirmed as generally recognised as safe by its own regulation, 21 CFR 184.1666, with good-manufacturing-practice maximum levels that cap it at 2.0 percent in general food categories. Glycerin’s status is split: it is listed as generally recognised as safe at 21 CFR 182.1320, where the entire operative text is that This substance is generally recognized as safe when used in accordance with good manufacturing practice.
; but glycerin made by one particular synthetic route is separately authorised as a food additive at 21 CFR 172.866, with a purity condition — It shall contain not in excess of 0.2 percent by weight of a mixture of butanetriols.
That limit traces straight back to the WHO committee’s note that such contaminants needed specifying.
Two things this does not tell you. Nobody has published a per-pouch exposure estimate for either substance, because nobody has measured the loading — so the comparison with an acceptable daily intake cannot actually be made. And the very large body of propylene glycol and glycerol toxicology that does exist comes from electronic cigarettes, where the substances are inhaled. That is a different route of administration and it does not transfer to something held against your gum.
Why dry pouches exist at all — the maker’s stated reason is appearance
The trade explanation for white, dry formats is usually shelf life or resistance to leaking. The patent file says something more mundane. The same Swedish Match application sets out the two manufacturing routes and then explains the naming:
Non-post-moisturized pouched products are sometimes referred to as “white snus” and are by some users considered to have a more appealing appearance.
Appearance. Not performance. The document is also the primary source for the classification everyone quotes: Generally, dry snuff has a water content of less than 10 wt% and moist snuff has a water content of above 40 wt%.
What I could not find anywhere is a measured shelf-life or leakage comparison between a dry and a moist pouch. I searched the patent for seepage, leaking and shelf life and the only hit attached to salt. The popular claim that dry pouches last longer or leak less has no primary source I can offer you.
What a humectant does to the nicotine: nobody knows
This is the cleanest negative on the page. The Altria-funded study ends at a hypothesis, and says so:
Volt and Loop, classified as wet pouch products, have higher moisture content and exhibited the slowest nicotine release profiles. This suggests that the presence of water and humectants in wet pouches may play a role in nicotine dissolution, a relationship worth further investigation.
Note the direction. In the one dataset that exists, more moisture went with slower release — the opposite of the industry’s long-standing suggestion that moist means fast. And on pH, the same paper reports two clean nulls: No clear trend was observed between pH and nicotine content, solubility, or moisture content.
and While pH does not influence the release of nicotine from the pouch, it can affect absorption in the oral cavity.
A 2026 review of pouch release physics makes the conceptual point better than anyone — Water activity reflects the thermodynamic availability of water rather than the total amount of water present and may therefore be more relevant to understanding release mechanisms.
— and then concedes the evidence is not there: Rather than assuming a universal concentration range, studies should report measured or declared humectant content when interpreting water activity and release.
I am citing it for framing and for its admissions, not as evidence: it is a single-author review funded by, and part-owned by, a company developing competing pouch carrier technology.
Why you cannot read any of this off the can
In Sweden, where snus is regulated as a food rather than as a tobacco product, the humectant is permitted without a quantitative cap and need not be declared on the tin. The Swedish Food Agency’s current regulation on snus requires packaging sold to consumers to carry net weight in grams, the manufacturing date, storage instructions where relevant, and the maker’s name and address. An ingredient declaration is required only for the nicotine-free snus-like products, which must carry en förteckning över alla ingredienser som ingår i produkten i fallande viktordning
— a list of every ingredient in descending order of weight. Real snus is exempt from that.
Which explains the odd position this subject is in. The industry’s voluntary standard caps nine unwanted substances — nitrite, total tobacco-specific nitrosamines, NDMA, benzo(a)pyrene and five metals — and says nothing about humectants, moisture or salt. What constrains them instead is food-additive law, arriving through a voluntary commitment to An ingredient policy consistent with the Swedish Food Act for additives and flavorings.
The whole constraint is that the humectant has to be a permitted food additive, and propylene glycol and glycerol both comfortably are.
Frequently asked questions
Do nicotine pouches contain propylene glycol? Some do and some do not. A survey of around fifty products counted propylene glycol declared on 25 of them and glycerol on 10. But the three major brands whose ingredient statements are publicly readable — ZYN, Velo and Rogue — name no humectant at all, and ZYN’s itemised list has no water on it either.
Is a moist pouch fresher than a dry one? It has more water in it. Whether that is better is a matter of preference, and the one dataset that measured release found the wet products the slowest to give up their nicotine. There is no measured shelf-life comparison between the formats.
Why doesn’t a dry pouch go mouldy? Because microbes cannot use water that is chemically bound, and a pouch at around 3.5% moisture has a water activity near 0.56 — well under the 0.85 threshold in food regulation and far below the 0.95 where most spoilage organisms are happy. No additive is needed to get there.
Is propylene glycol the same stuff as antifreeze? No, and the comparison is a confusion of two different glycols. Propylene glycol is affirmed as generally recognised as safe for food use in its own federal regulation, and the WHO’s expert committee set an acceptable daily intake of 0 to 25 mg per kg of body weight in 1973.
How much is in my pouch? Nobody can tell you. No manufacturer publishes a figure and no published study has measured it in a tobacco-free pouch. The only quantitative loadings in print are for snus and other tobacco products.
Does the humectant affect how strong the pouch feels? Unmeasured. The only published suggestion is one sentence in a sponsor’s discussion section calling for the work to be done. For what does set delivery, see nicotine delivery vs nicotine content and strength vs burn.
Sources
- Rutqvist LE, Curvall M, Hassler T, Ringberger T, Wahlberg I. “Swedish snus and the GothiaTek standard.” Harm Reduction Journal 2011;8:11. PMC3119032. Competing interests: all authors are or have been employees of Swedish Match AB. No funding statement.
- Swedish Match North Europe AB and Pely-tex GmbH & Co KG, “Oral pouched product”, European patent application EP 3 192 380 A1. Publication server text, European Patent Office.
- Platt T, et al. “Dissolution and physical characterization of oral nicotine pouch products.” PMC12864968. Funded by Altria Client Services LLC, an affiliate of the manufacturer of on! pouches.
- Chen L, McAdam K, Kimpton H, Porter A, Rodu B. “The composition of contemporary American and Swedish smokeless tobacco products.” BMC Chemistry 2019;13:59. PMC6661804. Funded by British American Tobacco; three authors BAT employees, one a paid BAT consultant.
- Mallock-Ohnesorg N, Rinaldi S, et al. “Oral nicotine pouches with an aftertaste? Part 1: screening and initial toxicological assessment of flavorings and other ingredients.” Archives of Toxicology 2023;97:2357. PMC10404176. Intramural funding, German Federal Institute for Risk Assessment; authors declare no conflict of interest.
- Engqvist H. “The Physicochemical Principles Governing Nicotine Delivery from Oral Nicotine Pouches.” Materials 2026;19(20):4410. PMC13707332. Funded by Emplicure AB; the author is a shareholder in that company, which develops pouch carrier technology. Cited as a review, not as evidence.
- US Food and Drug Administration, Inspection Technical Guide 39, “Water Activity (aw) in Foods”.
- 21 CFR 170.3(o)(16) (functional classes), 21 CFR 184.1666 (propylene glycol, GRAS affirmed), 21 CFR 182.1320 (glycerin, GRAS), 21 CFR 172.866 (synthetic glycerin, food additive), 21 CFR 117.3 (water activity definition), via the Electronic Code of Federal Regulations.
- Joint FAO/WHO Expert Committee on Food Additives, propylene glycol, WHO Food Additives Series No. 5 (1974), seventeenth meeting. INCHEM text.
- Joint FAO/WHO Expert Committee on Food Additives, glycerol, WHO Food Additives Series No. 10 (1976), twentieth meeting. INCHEM text.
- Livsmedelsverket, LIVSFS 2024:2, Livsmedelsverkets föreskrifter om snus, snusliknande produkter och tuggtobak, decided 16 February 2024. Official PDF.
- Manufacturer ingredient statements, checked 2 November 2026: ZYN, Velo, Rogue.
Every quotation above was checked character by character against the publisher’s or agency’s own copy on 2 November 2026, and the absences — of humectant terms on the three brand pages, and of any measured per-pouch loading in the literature — were confirmed by searching the downloaded documents rather than inferred.
