Tofu, cassava, wood, corn or paper: which plant litter suits which household

Line up the five plant litters sold in Britain and you are looking at a pea harvest, a cassava field, a sawmill's offcuts, a maize crop and a stack of yesterday's newspapers. None of them started out as cat litter. Each was milled, pressed or pelleted into something that would hold a cat's business, and the differences between them are larger than the shelf suggests: two of the five will not clump at all, which changes your week more than any claim on the front of a bag.

I make two of the five for a living, so take the recommendations with that in view. What I can offer in exchange is the part the roundups skip. Most guides give each material a paragraph of adjectives. This one explains what each thing actually is, what it does in a tray, where it fails, and what I would ask a manufacturer before buying it.

One number for scale before we start: the UK keeps 10.5 million pet cats, and 39 per cent of the people who own one own more than one.¹ Multi-cat homes are the ones where the maintenance differences below stop being academic.

Is plant-based cat litter good?

Plant-based cat litter does the same job as clay while being grown or recycled rather than mined. Bentonite, the standard clumping clay, is strip-mined and finite, it does not biodegrade, and by industry estimates the United States alone sends over two million tonnes of cat litter to landfill each year.² The five common plant materials, tofu, cassava, wood, corn and paper, all break down after use. Three of the five clump. The real cautions are practical: light plant granules travel further on paws than heavy clay does, and a cat that has used one texture for years needs a week or two to accept another. The RSPCA's advice is to mix the new litter in gradually over about a week, or to offer it in a second tray and let the cat choose.³

That answers the environmental question, which is the easy one. The harder two are whether a given material does the job well and whether your particular cat will accept it, and those depend on which material you pick.

Tofu litter: pressed plant fibre that clumps like clay

Tofu litter is a pressed pellet made from the fibre left over from plant-food production, typically soy okara or pea fibre, extruded into short cylinders a millimetre or two across.⁴ Despite the name there is no tofu in it. It clumps on plant starches and gums rather than on any mineral, it is light in the hand, and of the five it asks the least of anyone arriving from clay: scoop the clump, top up, no change of habit.

Our own tofu litter is built on pea fibre, pressed into pellets of roughly 1.5mm.⁵ Pea fibre rather than soy is a deliberate choice: it carries the absorption without the base note that soy okara brings, which is the note a good deal of the category answers with added fragrance.

The weakness is tracking, and it is ours to own. A light dry pellet rides out of the tray in paw fur and lands in the hallway. A textured mat under the tray catches most of it and what escapes sweeps up dry, but if you live in one room and cannot bear grit underfoot, read the wood section below before you buy ours. The second weakness is humidity: tofu clumps come out softer in a steamy bathroom than in a dry hallway, and a soft clump is a clump that can break on the scoop.

Cassava litter: fine grain, starch clumping, no mineral filler

Cassava litter is milled from the flour of the cassava root, the same starchy tropical crop that gives us tapioca. Ours blends cassava flour with corn starch, corn flour and guar gum, and clumps on the cassava's own starch rather than on any added mineral.⁶ The grain is finer and rounder than a tofu pellet, which matters more than it sounds: fine, even granules pour without bridging and sieve cleanly, which is what the rakes and sensors inside an automatic litter box are built to handle.

Cassava carries one question that deserves a straight answer rather than reassurance, which is that the raw root naturally holds a compound that can release cyanide. It is a fair thing to ask and the answer is a matter of processing chemistry, so we take it apart properly in a companion piece rather than waving at it here.

Wood litter: compressed sawdust, the pellet that stays in the tray

Wood litter is sawdust compressed into pellets under heat and pressure, usually softwood, usually with nothing else added at all: Pettex's, for example, lists compressed sawdust with no chemicals or additives.⁷ A wet pellet swells and crumbles back into sawdust, which is why the traditional wood tray is a sieve tray: soiled sawdust falls through to a lower chamber and the intact pellets stay above. Finer-milled clumping wood-fibre litters also exist in the UK,⁸ so "wood" on a bag does not tell you which routine you are buying. Check for the word clumping.

Wood is the material I would recommend to anyone whose deal-breaker is tracking. A pellet the size of a thumbnail does not leave the tray, and the RSPCA reports that wood pellets performed best in its own litter trials.³ Here is the qualification that the roundups leave out: in a field study of 18 cats, the animals showed a significant preference for clay or silica granules over wood pellets.⁹ So the material that suits the human best is one that a fair share of cats would not choose, which is the whole trade in one sentence. If your cat has always dug in something sand-like, offer wood in a second tray rather than switching the only one.

Softwood raises a phenol question worth handling honestly. Pine and cedar contain aromatic compounds that are a genuine concern in small-animal bedding, and commercial pellets are kiln-dried at high temperature, which drives most of them off. I have found no feline case literature establishing harm from kiln-dried pine litter, so the fair statement is that this is a reason to buy pellets sold as cat litter rather than raw stove or bedding pellets, not a reason to avoid wood.¹⁰

Corn litter: whole-kernel grain that clumps on its own starch

Corn litter is whole-kernel maize, or ground cobs, pressed into an absorbent granule that clumps on contact with its own starch; the best-known corn brand is built on exactly that.¹¹ It scoops like clay, it is soft underfoot, and it carries a faint sweetness of its own that you will either not notice or not like.

Two things are worth knowing before you buy it, and neither is a reason for alarm. The first is aflatoxin. Corn is among the crops most prone to Aspergillus moulds, whose aflatoxins cause liver damage in cats at sufficient dose, and a cat grooms its paws after using the tray. The response from the established manufacturers is heat treatment and batch testing, and I could find no documented case of a cat harmed by aflatoxin in litter, so this belongs in the category of a question to ask a brand rather than a hazard to flee.¹² What follows from it is practical: do not leave a corn tray wet and unscooped in a warm room, which is the condition moulds want.

The second is simpler. Corn litter is a grain, and grain in a warm cupboard is food for pantry moths and weevils. Owners report infestations, sometimes in bags opened for the first time; those are forum accounts rather than a measured rate, but the mechanism is ordinary enough to act on.¹² Store the bag sealed and cool, and buy a size you will get through rather than the biggest on offer.

Paper litter: recycled pellets, the most absorbent and the least discussed

Paper litter is recycled paper pressed into soft, highly absorbent pellets, and it is the one material on this list that generally does not clump.¹³ It is also the standard veterinary recommendation after abdominal or paw surgery, because a dust-free non-clumping pellet will not stick to a wound. For a kitten's first tray, or a cat with respiratory trouble, its softness and low dust make it a serious choice rather than a budget one.

Now the depth item, and I want to mark clearly where evidence ends and inference begins. Recycled paper is not a clean input stream. Liao and Kannan's survey of 202 samples across 15 paper product types found bisphenol A at microgram-per-gram levels in recycled-content products including napkins and toilet paper, and identified paper recycling itself as the contamination route, because thermal till receipts carry BPA that is not chemically bound and transfers to whatever it is pulped with.¹⁴ That is the established part. Here is the inference: no study I can find has measured bisphenols in paper cat litter specifically, so nobody, me included, can tell you what is in a given bag. What that justifies is a question to the manufacturer about the input stream and whether the pulp is de-inked, not a warning. I would rather hand you the question than a scare.

Which of them clump, and what that changes in your week

Tofu, cassava and corn clump. Paper does not, and the traditional wood pellet does not, though clumping wood-fibre versions exist.⁸ This is the single largest practical difference between these five materials, and it is the one the shelf hides.

With a clumping litter, each wee becomes a firm lump you lift out whole, so the tray runs on scooping and topping up. Guidance on how often the whole thing then needs replacing genuinely disagrees: Purina UK says a weekly full change for one cat on clumping litter, while cats.com, authored by a UK vet, says every two to four weeks.¹⁵ Scoop daily, as Battersea advises, and where you land between those two is mostly a question of tray size and how many cats share it.¹⁶

With a non-clumping pellet, urine is absorbed rather than isolated. Nothing lifts out except solids, the soiled layer accumulates underneath, and the routine becomes sieving or a full change of the affected portion on a shorter cycle. It is not necessarily more work: sieving twice a week can take less time than scooping daily. But it is a different job, and buying a sack of wood pellets expecting to lift out clumps is the disappointment I hear about most in this category.

There is a quieter argument for clumping that nobody sells on. A clump is a record. One firm lump per visit makes it obvious when a cat starts urinating more often, or barely at all, and both are changes worth taking to a vet early. A pellet tray absorbs that signal along with the urine.

Dust, tracking and the small flat

Two properties decide whether a litter is liveable in a small home, and they pull against each other. Dust is about particle size: fine milling makes a granule that feels sand-like to a cat and hangs in the air when you pour. Tracking is about granule size and weight: the bigger and heavier the piece, the less of it leaves the tray on a paw.

Ranked for tracking, wood pellets are the best of the five and paper pellets are close behind, because both are large. Tofu, cassava and corn all track, tofu most of all in my experience of shipping it. Ranked for dust, paper and tofu are the low end, and the mineral question below matters more than the plant material for anything in the middle.

Odour I will not rank, ours included. Across all five materials, how a tray smells tracks how it is run, how often it is scooped and how deep the litter sits, more than whose name is on the bag. Battersea's floor is at least 3 to 4 centimetres of depth, daily scooping, and one tray per cat plus a spare.¹⁶ Get those right and any of these five is liveable in a flat. Get them wrong and no bag will save you.

Kittens, and the cats who taste things

For a kitten the material question is mostly an ingestion question, because very young kittens sample litter while grooming and playing. With clumping sodium-bentonite clay, Cornell's Feline Health Center reports anecdotal accounts of gastrointestinal obstruction and calls ingestion "a particular concern with kittens", while stressing that the evidence is sparse rather than settled.¹⁷ A plant granule does not absorb and set the way bentonite does, which is the honest basis for preferring plant materials for a young cat: not that plants are magic, but that the specific swelling mechanism is absent.

For a first tray I would shortlist paper for its softness and low dust, or a fine plant granule such as our tofu litter, and I would insist on unscented whatever the material. Whatever is in the tray, a kitten that keeps eating litter needs a vet's opinion before it needs a different bag.

How do you dispose of biodegradable cat litter?

In the UK, used cat litter of any material goes bagged into the general waste bin. Biodegradable litters cannot go into council food or garden waste collections: the North London Waste Authority explains that used litter may carry urine and faeces and so fails composting facilities' acceptance criteria.¹⁸ Flushing is more restricted than the word "flushable" on a bag implies. United Utilities' rule is that only pee, poo and toilet paper belong down a toilet,¹⁹ and Wessex Water has cleared 35 kilograms of flushed cat litter from a single sewer blockage.²⁰ Our own line is deliberately conservative: scoop solids to the toilet only where your water company and local rules permit it, and everything else to the bin.

The word biodegradable on a bag describes what the litter is made of, not which bin it belongs in. If you compost at home, the North London Waste Authority's guidance is to remove faeces first and add only small quantities;¹⁸ I would add, as caution rather than quoted guidance, to keep the result away from anything you plan to eat.

What the label will not tell you

Here is the fact that reframes every claim on every bag in this category. Cat litter is not pet food, so no law requires it to list its ingredients, quantify a filler or stand behind the words on the front.²¹ A litter can be part ground limestone and say nothing at all, and the cheapest way to make a plant litter clump firmly is to add mineral. Some brands do disclose: pidan's tofu litter lists a silica and calcium carbonate blend, and Tuft & Paw's lists calcium carbonate beside soybean and pea fibre.²² Plenty of others say nothing, and are entitled not to.

Two kitchen tests settle it in a minute. Pour white vinegar on a spoonful: calcium carbonate answers with a sustained fizz, plant material does not, though a faint reaction can also be a baking-soda deodoriser. Stir a spoonful into warm water and leave it: plant matter swells and softens toward pulp, while inert mineral settles as grit on the bottom. What is still sitting there tomorrow is what would still be sitting in landfill years from now. Our cassava litter contains no added calcium carbonate or mineral filler of any kind, which is a claim we put in writing precisely because so few in this category do.

The five compared

Two rows in that table decide most purchases. If you want the clay routine without the clay, you want tofu, cassava or corn. If tracking is what you cannot live with, you want wood, and you accept sieving in exchange.

Whichever column is yours, the cat holds the casting vote. Switch gradually over about a week, or run the old and the new side by side and watch which tray gets used: that is the RSPCA's method,³ and it is ours too. And if the answer turns out to be wood pellets, buy the wood pellets. We sell two of these five materials, and a comparison is only worth writing if it stays true when the answer is not us.

Sources

1. PDSA, UK pet populations of dogs, cats and rabbits (PAW Mini Report 2025): 10.5 million pet cats; 24% of UK adults own a cat; 39% of cat owners have more than one cat. pdsa.org.uk
2. The Hidden Environmental Cost of Traditional Clay Cat Litter, Healthy Pet: bentonite strip-mined, finite, non-biodegradable; over two million tonnes of cat litter landfilled annually in the US by industry estimates. Graded as an industry source; the same one the house corpus already cites. healthy-pet.com
3. RSPCA, Cat litter and litter trays: "We saw wood pellets perform best in our trials; however, some cats may prefer a fine sandy litter"; advice to change litter gradually over a week or offer a separate tray. rspca.org.uk
4. Tofu litter's legume base and okara as the usual raw material: trade and manufacturer sources only. Graded C. The body states the mechanism and attaches no number to it.
5. CocoCat tofu litter: pea-fibre base, pellets of roughly 1.5mm. Confirmed against our own current production specification. First-party: our own product records.
6. CocoCat cassava litter composition (cassava flour, corn starch, corn flour, guar gum), unscented status, and the no-added-calcium-carbonate claim: live Shopify catalogue, and the published house article The hidden rock in "plant" cat litter. Our own product records and published house research.
7. Pettex Pampuss Natural Wood Litter, product listing (MedicAnimal): ingredients listed as compressed sawdust, no chemicals or additives. medicanimal.com
8. Greenwoods Plant Fibre Natural Clumping Litter, product listing (Bitiba UK): PEFC-certified plant-fibre clumping litter. bitiba.co.uk
9. Field study of 18 cats showing a significant preference for clay or silica granules over wood pellets: Villeneuve-Beugnet, V. and Beugnet, F., Field assessment of cats' litter box substrate preferences, Journal of Veterinary Behavior, 2018, vol. 25, pp. 65-70. doi.org
10. Phenolic compounds in softwood, and kiln drying as the standard treatment: the concern is established in small-animal bedding guidance rather than in feline case literature, and no feline case literature was found. Graded C. The body states the limit of the evidence and recommends pellets sold as cat litter over stove or bedding pellets, which is the actionable part.
11. World's Best Cat Litter (UK site): "made with whole-kernel corn"; "quick clumping and easy scooping". worldsbestcatlitter.com ; corn litter composition (ground kernels or cobs) and starch clumping also per A Complete Guide to the Different Types of Cat Litter, cats.com, cats.com
12. Aflatoxin risk in corn, and manufacturer heat treatment and batch testing: no primary feline case literature was found, and the body says so and makes no harm claim. Pantry-pest reports for corn litter are owner forum accounts only, with no measured rate. Both graded C, and the body attributes them as questions and reports rather than as data.
13. Bio-Catolet, 100% recycled paper cat litter (manufacturer site): pressed recycled paper granules, described by the maker as dust-free; sold as non-clumping. biocatolet.co.uk
14. Liao, C. and Kannan, K., Widespread Occurrence of Bisphenol A in Paper and Paper Products: Implications for Human Exposure, Environmental Science & Technology, 2011, 45(21), pp. 9372-9379: 202 samples across 15 paper product types; thermal receipts at 0.211 mg/g geometric mean versus 0.016 ug/g for other products; recycled-content products including napkins and toilet paper at microgram-per-gram levels; recycling identified as a contamination route. doi.org . Supported by Konkel, L., Thermal Reaction: The Spread of Bisphenol S via Paper Products, Environmental Health Perspectives, 2013, 121(3), a76, on unbound bisphenols transferring during pulping. doi.org . Note: neither study examined cat litter. The body states this explicitly and draws no conclusion about any litter product.
15. Full-change intervals disagree between sources: Purina UK (clumping, one cat: weekly), purina.co.uk ; cats.com authored by Dr Louise Barnes MRCVS (clumping: every two to four weeks), cats.com . The body reports the disagreement rather than choosing.
16. Battersea Dogs & Cats Home, How to create the best litter tray set up for your cat: "Use a soft, unscented litter that's gentle on paws", "Most cats like a soft sand-like surface", "Keep enough litter depth for digging, at least 3-4 centimetres", "Scoop out soiled litter at least once a day", one tray per cat plus one extra. Fetched 2026-08-04. battersea.org.uk
17. Cornell Feline Health Center, CatWatch, Does Clumping Kitty Litter Pose a Risk to Cats? (September 2024): anecdotal reports of gastrointestinal obstruction from sodium bentonite ingestion; "a particular concern with kittens"; evidence described as sparse and further study warranted. catwatchnewsletter.com
18. North London Waste Authority, Cat litter: general waste only; biodegradable litter excluded from food and garden waste collections; home composting guidance (remove faeces, small quantities). nlwa.gov.uk
19. United Utilities, Stop the Block: only pee, poo and toilet paper should be flushed. unitedutilities.com
20. Bath Echo, Wessex Water issues reminder after cat litter causes blockage nightmare (28 October 2020): 35kg of cat litter cleared from a single sewer blockage; "animal waste should never be flushed". Older than the other sources; the policy position it reports is unchanged. bathecho.co.uk
21. Pet food must declare ingredients and analytical constituents; cat litter is not classed as pet food and carries no such duty: Food Standards Agency, Pet food. food.gov.uk
22. Calcium carbonate on manufacturers' own ingredient lists: pidan tofu cat litter ("silica and calcium carbonate blend"), pidan.store ; Tuft & Paw Really Great Cat Litter, tuftandpaw.com