The biggest concerns of mine with more typical cat litter (clay/bentonite-based) are the level of lead, silica dust, and in some types, wood dust (or walnut shell dust).
The following types are non-toxic for cats as well as the person cleaning the litter box.
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Potential Toxins found in kitty litter
Lead: Tamara Rubin has tested cat litter with an XRF analyzer.
While most of the brands she tested did not have lead, she did find a brand with Lead (Pb) in the range of 27 +/- 11 ppm (equals 16 to 38 ppm) and one brand came in at 15 +/- 6 ppm Lead (source and source).
This is a low level, but because it’s in dust form and being tracked around by kitty paws this could be a concern to cats and could possibly lead to toxicity says Dr. Mwuara.
It’s also a concern for humans.
Clay-based/bentonite-based kitty litter, or litter with a clay ingredient is the type that can have these low levels of lead (as all clay-based products can).
Silica: Crystalline silica is not safe for you or your cat, as breathing it in is harmful.
The dust from crystalline silica can cause respiratory issues in cats, says Dr. Mwaura, and it has been linked to lung cancer and other health problems in humans (source).
Amorphous silica gel is generally safe for your cat and for people to handle.
Many clay-based cat litters (including bentonite clay) contain crystalline silica.
Wood dust: While the wood/bamboo/walnut shell, paper type litter products are usually labeled as low dust or 99% dust-free, breathing in wood dust is not safe for cats or humans.
Wood dust can cause respiratory or allergic reactions in cats, says Dr. Mwaura.
Wood dust is also a Prop 65 Chemical known to the state of California to cause cancer in humans (Proposition 65).
Walnut shell dust is not officially classified as carcinogenic, but walnut shells do contain tannins, phenols, and quinone-like compounds akin to those that are carcinogenic in hardwood dust (when inhaled), says Dr. Mudgal, our resident toxicologist.
Walnut dust could also cause irritation or allergic reaction when inhaled, says Dr. Mudgal.
Fragrance: Some cats don’t do well with scented litter which can trigger allergic reactions and/or respiratory problems in cats, says Dr. Mwaura.
Many humans are also sensitive to fragrance chemicals. If you are a regular reader of my site then fragrance in cat litter is probably not for you.
Recycled Tires: While this type looks like it might have been discontinued, recycled tires contain many contaminants of concern that are outlined in my article on gym flooring.
Old tires release compounds including VOCs, polyaromatic hydrocarbons, and toxic metals.
1. World’s Best Cat Litter
World’s Best Car Litter is corn-based.
It’s made of whole-kernel corn grown in the US.
Real users say it does a great job of clumping and produces very little dust, but it doesn’t control odor as well as clay-based litter does.
Reviewers did also report some tracking.
This brand is 99% dust-free, free of silica dust, and free of harmful metals.
It tested positive for low levels of Bromine (Br): 4 +/- 1 ppm, Zinc (Zn): 27 +/- 5 ppm and Iron (Fe): 62 +/- 13 ppm.
It tested non-detect/negative for all harmful metals, including: Lead (Pb), Arsenic (As), Cadmium (Cd), Mercury (Hg), Barium (Ba), Selenium (Se), and Antimony (Sb) (source).
I would recommend going with the unscented, because added fragrance is not always tolerable for everyone.
The pros: it’s biodegradable, made from a renewable resource, low dust, flushable, safe for septic and sewer systems.
The cons: some cats (and humans) may be allergic to corn, not as good at odor control compared to other types, more expensive than clay-based litter.
2. Dr. Elsey’s Crystal Attract Cat Litter
“Crystal” or amorphous silica cat litter is non-toxic and completely safe for cats and humans.
Dr. Elsey’s Crystal Attract is a well-liked brand.
Crystal cat litter is composed of amorphous silica gel granules (this is very different from crystalline silica, which is harmful to breathe in).
It’s absorbent and lightweight.
Liquid and odors are trapped.
It’s as low-dust as you can get. It does track somewhat like all litter materials do, but putting a mat outside the litter box does help.
The pros: it’s non-toxic, very absorbent, long-lasting, has good odor control, is easy to clean, is low-dust compared to clay, and is lightweight, good for many cats that have allergies or respiratory problems.
The cons: has to be mined (harder on the environment than a recycled product or one made from waste materials), not biodegradable, tracks easily, more expensive than other types, some cats may not like the texture, can get dusty.
3. sWheat Scoop Original
Made from 100% natural wheat grown in the US, sWheat Scoop Original clumps fast, scoops easily, and smells like a fresh wheat harvest.
They say it is virtually dust-free (99.5% dust-free, though reviewers did notice some dust), and tracking is minimal (though some reviewers didn’t find the tracking to be low).
They have an option that is intended for only one cat as well as a multi-cat option.
It has odor-neutralizing enzymes and clumps well.
I would recommend the unscented version.
The pros: flushable, 100% biodegradable, renewable resource, low dust, good odor control, good clumping ability.
The cons: possible allergy to wheat (humans or cats), not as absorbent as other types, more tracking the other types, could attract insects when left too long, more expensive than clay-based litter.
4. Tofu Litter
There are different formulations that fall under “tofu” cat litter.
I would avoid the formulas with added bentonite clay, added fragrance or without a full ingredient list.
Tuff+Paw uses soybean fiber, calcium carbonate, corn starch, pea fiber, activated carbon.
They say it’s 99% dust free.
VETRESKA Deodorant Tofu Cat Litter, in the non-scented version, is made from pea dregs, corn starch, guar gum, and “STA deodorant beads”.
The problem for me here is they don’t say what these STA deodorant beads are made of.
They say “dust-free” but don’t provide a percentage.
Pros: Users say that the Tuff+Paw basically doesn’t track at all. Flushable, biodegradable, usually well liked by cats.
Cons: The people are divided on odor control. It’s the most expensive option on this list.
| World’s Best | Dr. Elsey Gel | sWheat | Tuff+Paw | |
| Type | Corn | Amorphous silica | Wheat | Soy & pea based |
| Dust | 99% dust free | 99.9% dust free | 99.5% dust free | 99% dust free |
| Odor Control | Mediocre | Great | Good | OK to Good |
| Tracking | Yes | Yes | Yes | Almost None |
| Clumping | Great | Doesn’t clump in the same way but still works well | Great | Great |
| Cost* | Around $1.15 per pound | Around $2.70 per pound | Around $1.10 per pound | Over $3 a pound. |
Corinne Segura is an InterNACHI-certified Healthy Homes Inspector with certifications in Building Biology, Healthier Materials and Sustainable Buildings, and more. She has 10 years of experience helping others create healthy homes. You can book a consult here.
Nancy
I had used D. Eisleys litter for years. I never recognized a problem. Until,Beginning of March 2026, I purchased a large litter box with a removeable spray guard. With the litter the box was too heavy for me to lift and clean. I put the new large box, removed spray guard, into a construction bag, then put my old box into a lighter plastic bag and set it into the big box it fit fine. Poured the litter into it. Dust was everywhere, I’d wipe down the dust with Clorox wipes. Every time I cleaned the box several time daily, more dust came up every time the cat when in it. I became i*l , lost my v*ice, couldn’t s****ow, n*se constantly r***ing , c****ing and c***t h**t. Had en******y, Today the 3/20/26, am on anti******s, m*ds to help me s*****w and eat a little soft food, m*ds to stop the n*se running with c***s of yellow gunk. C****ing, t****d. When I researched and realized what is in the litter, it scared me. The time coincides with me getting i*l and purchasing a new box. My cats voice is r***y and she yowls a lot I just purchased horse blanket pellets, pine, it is too smelly for inside the home. My cat won’t use it, I put it outside because my as***a’s acting up, my cat runs away from it. I am trying to find a litter, no clay, no scents, no smell, safe and not harmful to humans and pets, with no dust. Why don’t MFg. make safe litter, not from mines or harmful ingredients. If I am i*l what is happening to my beloved 10 lb cat named Calico. Is she going to d*e because of irresponsible companies who hawk that their litter is the best, and yet our pets are getting i*l or may d*e because of gr**d and not making sure their product is safe?.
Melissa
Hi Corinne,
Thanks so much for this info! What do you think about FUKUMARU Tofu Cat Litter?
Thank you,
Melissa
Corinne Segura, Building Biologist
it contains wood which is on the “not my favorite” list in the beginning of the article
Jeanice Barcelo
World’s Best Cat Litter uses GMO corn. Cats are eating it and mine developed an a******l t***r that I would bet is caused by years of eating the GMO corn off her paws. I do not recommend this litter or any product containing GMO ingredients.
Nikki
I am wondering about the PFAS pesticides sprayed on corn. Will there be noticeable residual after the litter is reduced? I don’t suppose there is anyway of avoiding some contaminants in the States at least.
Corinne Segura, Building Biologist
I would expect the litters to have some pesticide residues those those are usually reduced when it’s processed.
Nikki
Thank you for the info! It is what I suspected, but I had not found any good studies upon it. (Also, apologies for the spelling error; I meant “produced.”)
Doreen
I love horse bedding pellets for cat litter – super cheap ($7.00 for 40 pounds) and no tracking or odour. Natural and safe 🙂 I’m in Florida and get mine at Tractor Supply.
Jeanice Barcelo
Do you know what the horse bedding pellets are made of? This is such an interesting idea!
Doreen
Primarily pine – I have 8 cats (kitten – senior) and they all love it and have had no negative effects. I purchase mine at Tractor Supply for $7.19 for 40 pounds. Put a THIN layer in the box and scoop out the poop ( I use a doggie bag – the same I use for my dogs on walks) the pee will eventually turn the pellets to sawdust – just empty into trash and add fresh pellets. No odor and no tracking:) A 40 pound bag lasts about 2 months.
Jeanice Barcelo
Thanks Doreen. Why only a thin layer? My cats are used to having about 4 inches of litter.
S
Hello, thank you for your thorough and detailed analysis of these different cat litters. I am wondering if any tests are done to determine if the field-grown ingredients (corn, soy, wheat) are grown/harvested without the herbicide glyphosate (organic, so to speak)?
Corinne Segura, Building Biologist
I doubt they are made from organic corn, wheat, soy etc
S
rob
What is your financial interest in the products you are promoting to cat owners? How much glyphosate, fertilizers, herbicides and crop ripening chemicals are present in these products?
Jeanice Barcelo
ALOT and I am willing to bet that litters made from GMO corn (like World’s Best) are causing a******l t****s in cats.
Jeanice Barcelo
You are correct. World’s Best is made from GMO corn. I asked them directly. I view this as a major health threat for my cats because they eat the corn off their paws. I’m done using anything with GMO ingredients. I don’t know what we’ve been thinking imagining that this is OK.
Ka
Have you tested Okocat ?
It is wood and has potential for wood dust but can you test/have you tested for the levels of dust ?
I just want to make the best decision
Corinne Segura, Building Biologist
I would think that the dust varies from batch to batch, I don’t know how that is measured exactly or what level is considered safe. I know CARB gives no clear guidance on what level is safe last i checked.
Kelci
Have you ever tested Cassava based litter? The litter I use is corn and cassava based, “Sustainably Yours”. I recently read a consumer reports article about cassava being easily contaminated by lead.
I’m wondering how much I should worry, or if I should switch litter to be safe?
Corinne Segura, Building Biologist
Cassava looks to have 0.3 ppm lead which is much lower than the background ppm of lead in soil outside. https://www.umass.edu/agriculture-food-environment/soil-plant-nutrient-testing-laboratory/fact-sheets/soil-lead-fact-sheet?
Masha
The link to Dr. Elsey’s leads to bentonite clay.
Is this the product you’d recommend? It says is Silica sand without crystalline (not sure).
Corinne Segura, Building Biologist
oh ya, thank you so much. it’s meant to be this one https://www.drelseys.com/products/clean-air-litter/
Madha
Thank you so much!
Pa
What about “tofu” litter made of pea shells? My new preferred litter for functionality & actually low dust. Hopefully it’s low in contaminants. Strongly disliked all the ones you listed. They are all very dusty and goopy/crumbly. Walnut one stained my cats paws red. Dr Elseys has a cult following but all their products are not worth the hype. That silica one gets everywhere like sand! And stinks so bad of urine in a few days.
Corinne Segura, Building Biologist
I’m going to add the “tofu” litter to the post
Lily
Thank you so much, this info is very helpful. All four of my cats have been losing their fur, scratching, licking, biting constantly. I’ve done food elimination diet but that’s not helping. My vet and I cannot figure it out. I used Worlds Best but it is 100% dust and very messy; WorldsBest brand is way too expensive for failing to live up to their claims. I usually use Okio wood pellets but am thinking there are chemicals and toxins in this liter. So there is absolutely no liter out there that is truly 100% non-toxic?! 🙁
Mariane Konstantaras
Corinne,
Would you be concerned about glyphosate residue on the corn litter? I bought it and yes I like it overall but it does track and I’m concerned that this could be an issue? Thoughts?
Corinne Segura, Building Biologist
I wouldnt be, since it’s minor but you could try the second type if you are
ann
Hi thnx for all your great information:) Just curious what you think of Feline Pine non clumping litter? My cats are used to it and it does not contain artificial fragrance but of course it is wood pellets.
Corinne Segura, Building Biologist
potential for wood dust which is a carcinogen
Kimberly Roush
Corinne
I struggled with cat litter for years. The grains and the walnut shells are all pesticided plus Swheatscoop exposes the cat to gluten.
I opted for purchasing organic polenta from Natural Grocer.
I still do not trust the silica.
Kimberly
Pa
Interesting! Does it clump urine? Does it get gummy?
Corinne Segura, Building Biologist
im interested in knowing how that worked as well
Miriam
My cats like the Naturally Fresh (recycled walnut hulls). Clumps well.. tracking is easy to sweep up . Minimal dust
Hailee
This is what I use too. But am concerned about mold? I know a lot of nuts are known for mold. Thoughts?
Corinne Segura, Building Biologist
I am more concerned about the dust from walnut shells being a similar composition to the carcinogenic compounds in wood dust.
Starr Adams
Hi Sarah, I would be concerned about residual glyphosate in the corn and wheat-based products since the majority of those crops are sprayed with it.
Sarah
Also, if you have a finicky cat (is there any other kind?!) and they will only use a litter that produces dust, don’t use a littler box w/a lid since it holds the dust inside forcing them to breathe more of it in.