Written by the Kopipets team · Singapore · Published 1 August 2026 · Last checked against published standards and test data 1 August 2026
We sell tofu cat litter, so read this with that in mind. This page links to our own test results, to other articles on this site, and to one external source. It contains no product links. It also contains a downgrade of a number we have been publishing about ourselves for months.
The short version
At the end of our article on formaldehyde we said something we owe you the rest of: formaldehyde is a question you settle once, when you decide whether to trust a manufacturer. Dust is a question you live inside every day, twice a day, for as long as you own the cat. The attention online is allocated the other way round.
There are two measured dust figures in the tofu cat litter standard, and they are not the same thing. Powder content is how much loose powder is already in the bag when it leaves the factory. Pulverisation rate is how much new powder the pellets create when they are ground against each other, which is what happens when a cat digs. A litter can be clean in the bag and crumble in the box, or dusty in the bag and hold up perfectly once it is in use. One number will not tell you about the other.
Ours are 0.66% powder content and 0.36% pulverisation rate. Until today, everywhere else on this site quoted those two figures against the standard's outer limits of 1.5% and 1%, which is true and is also the most flattering true way to say it. The fuller version is below, and one half of it is not flattering.
And then there is the number that does not exist. Neither figure — nor any figure published by any brand, standard or consumer test we have been able to find — measures the fraction of litter dust small enough to reach the deep lung. That measurement is simply not taken anywhere in this industry. We are not going to pretend otherwise in order to sell you a bag.
The two numbers, and what each one actually measures
T/CIQA 11-2020 is the Chinese association standard written specifically for tofu cat litter, published by the China Inspection and Quarantine Association. It is the standard our own litter was tested against. It is not a Singapore regulation, it is not a government standard anywhere, and it does not apply to bentonite, crystal, paper or wood litter. It is an industry association's document, and its usefulness is that it defines methods precisely enough that two laboratories testing the same product should get comparable answers.
The two dust methods it defines, in the standard's own terms:
Powder content (含粉率) — sieve a set quantity of litter and weigh what falls through a 30-mesh screen, as a proportion of the sample. Nothing is done to the litter first. This is a static measurement of the powder that is already there, produced during manufacture and handling and sitting at the bottom of the bag by the time it reaches you.
Pulverisation rate (粉化率) — take the litter that already passed the sieve stage, run it through an attrition test in a pulverising apparatus, then sieve again. This is a dynamic measurement of powder that did not exist before the test and was created by mechanical stress. It stands in for a cat digging, a scoop dragging through the bed, and the pellets grinding against each other every time the box is used.
The standards bodies behind the largest recent comparative test put the distinction more plainly than we could: low powder content does not mean low pulverisation rate. Powder content reflects how much powder is in the litter when it leaves the factory; pulverisation rate reflects whether the litter breaks up easily during actual use and generates new dust.
This matters for a practical reason. If you have ever bought a litter that seemed clean when you first poured it and turned into a grey haze by week two, you were not imagining it and you were not doing anything wrong. You bought a product that was good on the first number and bad on the second. Almost nobody publishes the second number, so there is no way to have avoided it except by buying the bag and finding out.
What the grades say, and where we actually sit
Here is the part we have been leaving out.
T/CIQA 11-2020 does not set a single pass mark for dust. It sets three grades. For powder content the thresholds are 0.5%, 1% and 1.5%. For pulverisation rate they are 0.5%, 0.8% and 1%. Premium grade is the tightest band, first grade is the middle, and qualified grade is the outer limit — the number we have been quoting.
Against those bands:
Our pulverisation rate is 0.36%. That is inside the premium band. The pellets hold together under attrition better than the standard's top grade requires.
Our powder content is 0.66%. That is first grade. It is not premium grade. Premium would have required 0.5% or below. We are 0.16 percentage points outside it, and every time we have written "0.66% against a 1.5% limit" we have been comparing ourselves to the easiest of the three bars available.
That is a real gap and we would rather you heard it from us. It is also, we think, an interesting gap, because of which one it is. Pulverisation rate is mostly a function of formulation and pellet hardness — how well the thing is made. Powder content is mostly a function of finishing: how thoroughly the fines are screened out before the litter goes into the bag, and how gently it is handled afterwards. On the formulation measure we are at the top grade. On the finishing measure we are one band down. The most likely reading is that our pellets are sound and our screening is not as tight as it could be, and that is the conversation we are now having with the manufacturer rather than a conversation we are having with you about how good we already are.
Two honest caveats on all of this. Both figures come from one report on one set of samples: Centre Testing International, report A2250276330101001C, tested April–May 2025. They describe that production, not every bag we have ever sold. And the grades above are a Chinese association standard's grades, not a legal classification in Singapore or anywhere else. A brand can call itself premium in this category without anything at all standing behind the word.
The measurement that does not exist
Now the more uncomfortable point, which applies to us and to every competitor equally.
The sieve that defines powder content has an aperture measured in hundreds of micrometres. Anything that falls through it counts as dust; anything that does not, does not count.
The size that matters for the deep lung is very different. ISO 7708:1995, the international convention for defining particle size fractions in health-related sampling, puts the respirable fraction — the part of inhaled dust capable of reaching the alveolar region — at a median cut-off of 4.25 micrometres. Coarser conventions exist for the parts that stop in the nose and throat, but 4.25 µm is the number that describes what gets all the way in.
So the industry's dust measurement is defined by a screen that would let essentially the entire respirable fraction pass through unrecorded, mixed in with a much larger mass of material far too big to inhale at all. Powder content is a useful figure — it tells you how much visible mess is in the bag, and visible mess is a real annoyance and a real cleaning burden. It was never designed to be a health measurement, and it is not one.
What would a health measurement look like? Something like an aerosol chamber: pour or agitate a fixed quantity of litter under controlled conditions and measure the airborne particle mass by size fraction over time. That method is routine in occupational hygiene. As far as we can find, it has never been published for cat litter — not by a standards body, not by a consumer council, not by a brand, and not in the peer-reviewed literature. If you know of one, we would like to see it, and we will put it on this page whether or not it flatters us.
Until then, anyone telling you their litter is safer for your lungs, including us, is extrapolating from a sieve.
What the largest recent test found when it looked at both
In November 2025 the consumer councils of Macau, Shenzhen, Zhongshan and Guang'an jointly tested 40 cat litter products across several categories and published the full results. It is the largest comparative test in this category we are aware of, and its findings are the reason we think the internet's priorities are inverted.
On formaldehyde, all forty samples met the applicable limits. Forty out of forty. The test did not separate good products from bad ones on formaldehyde at all, because on that measure there was nothing to separate.
On dust, the same forty samples spread out enormously. Powder content ranged from 0.05% to 3.48% — a factor of roughly seventy between the cleanest and the dustiest. Pulverisation rate ranged from 0.28% to 1.20%. The councils judged that indicator against T/ZGXX 0005-2022, a general cat litter specification whose requirement is 1.20% or below, rather than against the pulverisation band of the tofu-specific T/CIQA 11-2020 we are measured under, which is 1%. All forty passed, with the dustiest sample sitting exactly on the line. The powder content figures came with no limit attached at all. The councils published the spread and noted that twenty-five of the forty came in within 0.20%, but they named no standard for that indicator and set no pass mark. Ours is 0.66%, judged against T/CIQA 11-2020 because that standard covers tofu litter specifically.
Of the nine indicators the test reported, dust took two of them and formaldehyde took one. The people who designed that test allocated their attention roughly the way we think a cat owner should.
One thing that test does not support, and which we are not going to claim: it did not publish results broken out by litter category in a way that lets anyone say tofu litter is less dusty than bentonite, or than anything else. The spread was across all forty products. We sell tofu litter and it would suit us to tell you the category wins. We do not have the data to tell you that.
Why the attention is allocated backwards
We think there are three reasons, and none of them are conspiracies.
Formaldehyde is a word with a threat attached. It has a chemical name, an IARC classification, and a story about furniture factories. Dust is a word with an inconvenience attached. Threat words travel further than inconvenience words, and a search result about formaldehyde will always be clicked more than a search result about screening tolerances.
Formaldehyde also has a satisfying answer shape. You test once, you get a number, the number is below a limit, you are done. Dust does not resolve. It is a distribution with two measurements, neither of which describes the thing you would most want to know, and the honest answer is a range rather than a verdict. Content that resolves outperforms content that does not.
And formaldehyde is a supplier problem, which means it can be solved by choosing a supplier. Dust is partly a supplier problem and partly a physics problem: dried plant fibre pressed into pellets and then ground by a cat will always shed something. There is no brand you can buy your way out of it with, including this one, and copy that ends in "there is no perfect answer" does not sell.
None of that makes formaldehyde unimportant. It makes it a question you should ask once, hard, of any manufacturer, and then stop thinking about. Dust is the one you are still living with in month six.
What the veterinary literature actually says about litter dust
Less than you would expect, and we think you should know that before you weigh our opinion or anyone else's.
The American Association of Feline Practitioners and the International Society of Feline Medicine publish the two documents most often pointed at as the authority on litter box design: the 2013 Feline Environmental Needs Guidelines and the 2014 Guidelines on Diagnosing and Solving House-Soiling Behavior. Between them they cover box size, number of boxes, placement, depth of litter, cleaning frequency, substrate texture preference and scent. Neither document mentions dust. Not as a recommendation, not as a caution, not once.
That is not the same as those bodies saying dust does not matter. It is those bodies not having addressed it, which is a different and weaker statement, and anyone citing them as recommending low-dust litter — we have seen it done — is citing something that is not in the document.
The human side is thinner still. The published literature on cat litter dust and human respiratory disease that we can find consists of individual case reports: one describing a woman keeping nine litter boxes in a 44 m² flat over eighteen years, another describing a woman with eight cats. Case reports of one patient are how medicine notices that something might be worth studying. They are not how it establishes that something is.
So the state of the evidence is: an obviously real exposure route, essentially no measurement of the fraction that would matter, and no controlled study in either species. That is an argument for keeping dust low as a sensible precaution and for handling it as a cleaning and comfort issue you can actually verify. It is not an argument for a health claim, and we are not making one.
Singapore's own indoor air numbers, and why they do not help you
Singapore has published indoor air guidance: the NEA's Guidelines for Good Indoor Air Quality in Office Premises, issued in 1996. They set an eight-hour figure of 150 µg/m³ for PM10 and a figure for formaldehyde alongside it.
Two things follow. The first is that they are office guidelines. They are not a residential standard, they have no application to an HDB flat, and no brand — including us — is entitled to say its litter meets a Singapore indoor air limit for homes, because there is no such limit to meet.
The second is the part we find genuinely instructive. The only Singapore indoor air document we have puts particulate matter and formaldehyde side by side and gives them each a number. It treats them as two problems of comparable seriousness. That is more even-handed than almost anything written about cat litter, which is our whole point on this page.
What we have got wrong on our own site
Applying this article honestly means marking our own homework, and we come out of it with three failures.
Our packaging says 100% dust-free. We admitted this in our article on tofu litter safety and it is still true: stock printed with that wording is still in circulation. No litter made of pressed plant fibre is dust-free, our own measurements say so, and the claim was wrong when we wrote it. The wording that replaces it will be the measured figure rather than an adjective.
We published a comparison table that graded other litter categories' dust with adjectives. Until this article went up there was a table on this site telling you clay is high dust and tofu is very low, and a top-ten page giving named competitor products dust verdicts. We have laboratory data on exactly one product in this category: our own. Every one of those other gradings is an adjective with nothing behind it, which is precisely the practice we criticised in our safety article as "a free adjective". We were doing it on the next page over. Those gradings came off before this page was published. What stands in their place is a note on each page explaining why they went.
We had been quoting our dust figures against the loosest of three available bands. Corrected at the top of this page, and corrected on the product page, the test report page and both litter guides on the day this article went up. The correction is visible rather than quietly swapped in.
We would rather publish this than have a reader find it. It is also, straightforwardly, the reason to trust the numbers we do publish: a brand that only ever discovers flattering facts about itself is not checking.
What is actually within your control in an HDB flat
None of the following is measured, by us or by anyone. It is what we do and what customers tell us works, offered as that and nothing more.
Most of the airborne dust in a litter routine happens in two moments: the pour and the scoop. Pouring from height turns the fines already in the bag into an aerosol; pouring low and slowly, with the bag mouth close to the litter surface, does not. The last portion of any bag carries more fines than the first, because powder settles — if you are sensitive, that is the portion to pour most carefully rather than the one to tip out fast.
A deeper bed means a cat digs into litter rather than scraping the tray floor, and scraping the floor is where a lot of pellet breakage comes from. We suggest five centimetres or more for our own litter for that reason, not only for clumping.
A covered box contains scatter and whatever becomes airborne inside it. It also concentrates that air where the cat's head is, so it is a trade between your air and theirs; if the box is covered, the case for cleaning it more often gets stronger rather than weaker.
And the honest limit of all of this: if a member of your household has asthma, none of the above is a substitute for asking their doctor, and no litter measurement published today can answer the question you would actually be asking.
Where we could be wrong
We are a pet supplies retailer. We are not an occupational hygienist, a toxicologist or a laboratory, and nothing here is veterinary or medical advice.
Specific limits on what we have told you. Our own two figures come from a single report on a single set of samples in April and May 2025; we have committed to re-testing and to publishing the new report alongside the old one rather than replacing it. The grades we have placed ourselves in come from one association standard that covers tofu litter only — we cannot use it to say anything about bentonite, crystal, paper or wood litter, and neither can anyone else. And the central claim of this page, that no one measures the respirable fraction, is a claim about the absence of evidence. We have looked; absence of evidence found by looking is still weaker than evidence, and one published study would overturn it.
If you find an error on this page, or a source that contradicts it, we would rather hear about it than not.
Questions we get asked
What is the difference between powder content and pulverisation rate in cat litter?
Powder content is how much loose powder is already in the bag when it leaves the factory, measured by sieving a sample and weighing what falls through. Pulverisation rate is how much new powder the pellets generate when mechanically ground in an attrition test, standing in for what a cat does when it digs. A low powder content does not imply a low pulverisation rate, and a litter can be clean in the bag while breaking down badly in use.
Is there a dust standard for cat litter?
For tofu cat litter specifically, T/CIQA 11-2020 sets graded limits: powder content at 0.5%, 1% and 1.5% and pulverisation rate at 0.5%, 0.8% and 1% for premium, first and qualified grade respectively. It is a Chinese industry association standard, not a government regulation, and it does not cover bentonite, crystal, paper or wood litter. Singapore has no cat litter dust standard that we are aware of.
How dusty is Kopipets tofu cat litter?
0.66% powder content and 0.36% pulverisation rate, tested by Centre Testing International in April and May 2025 under report A2250276330101001C. Against T/CIQA 11-2020 that places the pulverisation rate in the premium band and the powder content in the first-grade band — first grade, not premium. Premium would have required 0.5% or below on powder content.
Is any cat litter genuinely dust-free?
No litter made from pressed plant fibre is dust-free, and we do not believe any category is. Our own measurements are low but they are not zero, and a brand printing "100% dust-free" on a bag is either not measuring or not telling you what it measured. We printed it ourselves and we were wrong to.
Does cat litter dust cause asthma in cats or people?
There is no controlled study establishing that, in either species. The published human literature consists of individual case reports involving extreme conditions, such as nine litter boxes in a small flat over many years. The exposure route is obviously real — cats groom what settles on their paws — but its size has not been quantified, and anyone stating it as an established cause is going beyond the evidence.
Do vets recommend low-dust cat litter?
The AAFP and ISFM litter box guidelines, the 2013 environmental needs document and the 2014 house-soiling document, do not mention dust at all. That is not the same as saying it does not matter; it means those bodies have not addressed it, and citing them as recommending low-dust litter is citing something the documents do not say. If your cat or a member of your household has a respiratory condition, that is a question for a vet or a doctor rather than for a retailer.
Which matters more in cat litter, formaldehyde or dust?
They are different kinds of question. Formaldehyde is settled once, by checking a manufacturer's test report before you commit to them; in the largest recent comparative test, 40 out of 40 products met the applicable formaldehyde limits, so it did not distinguish products at all. Dust distinguished them enormously in the same test, with powder content ranging from 0.05% to 3.48%, and it is the exposure that repeats every day for the life of the product.
Does anyone measure the respirable fraction of cat litter dust?
Not that we can find. ISO 7708:1995 places the respirable cut-off, the fraction reaching the alveolar region, at a median of 4.25 micrometres. The sieve used to define powder content in cat litter has an aperture hundreds of times larger, so it would let essentially the whole respirable fraction pass unrecorded. No standards body, consumer council, brand or published study we have located reports airborne particle mass by size fraction for cat litter.
Sources and standards referred to
T/CIQA 11-2020, Tofu Cat Litter, China Inspection and Quarantine Association — the graded limits for powder content and pulverisation rate, and the standard our own product was tested against.
T/ZGXX 0005-2022, Pet cleaning and hygiene products — cat litter (pulverisation rate requirement of 1.20% or below, the standard the four-council comparative test judged pulverisation against).
ISO 7708:1995, Air quality — Particle size fraction definitions for health-related sampling — the respirable convention and its 4.25 µm median cut-off.
Four-council comparative test of 40 cat litter products, Macau, Shenzhen, Zhongshan and Guang'an consumer councils, published 26 November 2025 — the 0.05%–3.48% powder content spread, the 0.28%–1.20% pulverisation spread, and the 40/40 formaldehyde result.
American Association of Feline Practitioners and International Society of Feline Medicine, Feline Environmental Needs Guidelines (2013) and Guidelines on Diagnosing and Solving House-Soiling Behavior in Cats (2014) — cited here for what they do not contain.
National Environment Agency, Guidelines for Good Indoor Air Quality in Office Premises (1996) — the PM10 figure of 150 µg/m³, applicable to offices and not to homes.
CTI report A2250276330101001C, all seventeen results reproduced on our test report page.
About this article
Kopipets is a Singapore pet supplies brand for cats and dogs, operated by Surplus Media Pte. Ltd. (UEN 202448810R), a Singapore-registered company and the importer of record for the products we sell. We hold our own stock in a local warehouse, inspect it on arrival, and deliver islandwide with our own vehicles.
This page was written by the Kopipets team and last checked on 1 August 2026. We will update it when we re-test, if an airborne measurement for cat litter is ever published, or when a reader shows us we got something wrong. Corrections will be noted here rather than quietly edited in.
Corrections to this page. 1 August 2026, the same day it was published. Several sentences described changes to other pages on this site as still to come, when those changes had in fact already been made before this page went up; they were rewritten into the past tense. One sentence said our replacement packaging wording was already the measured figure, which it is not yet, and it now says so. Two entries in this page's structured data were reworded to match the visible text they stand for: one question and one answer. The description of this page's own outbound links was corrected. No figure, no source and no conclusion changed. Later the same day: the 1.20% pulverisation ceiling quoted for the four-council comparative test was unattributed, and is now named as T/ZGXX 0005-2022 and added to the sources list, and the same paragraph now records that the powder content figures in that test carried no standard at all.
Related reading: formaldehyde in cat litter and how to read a test report, is tofu cat litter safe, and our honest buyer's guide to tofu cat litter in Singapore.
