Stainless steel vs plastic litter trays: which smells less?

A stainless steel cat litter box smells less than a plastic one over time because steel is non-porous: urine can't soak into it, so there is nothing for bacteria to live on once you've washed it. Plastic starts out just as clean, but every scratch from a scoop or claw opens a groove that holds odour, and after a year or two no amount of scrubbing gets it out. This guide compares the two materials on smell, hygiene, cost, weight and cat preference, so you can decide whether it's worth switching.

Why plastic litter trays start to smell

Plastic is slightly porous to begin with, and it gets worse with use. Three things happen:

• Scratches. Claws and metal scoops score the base. Each scratch is a channel that traps urine and litter dust.
• Absorption. Ammonia from cat urine penetrates the surface of polypropylene over months. The tray smells faintly even when empty and dry.
• Bacterial film. A rough surface gives bacteria somewhere to attach. The film regenerates between washes, so the smell comes back within days.

The usual advice is to replace a plastic tray every 12 months. Most people don't, and the "cat smell" in the house is often the tray itself rather than what's in it.

Stainless steel vs plastic litter trays compared

Factor	Stainless steel	Plastic
Odour retention	None; non-porous	Builds up over months
Scratch resistance	Very high; surface scratches are shallow and don't absorb	Low; scratches hold odour
Cleaning	Washes clean with hot water; can be disinfected without damage	Harsh cleaners cloud and weaken it
Lifespan	Many years	Around 12 months before it should be replaced
Weight	Heavier; more stable, harder to tip	Light; easy to carry, easy to knock
Cost	Higher upfront	Low upfront, replaced more often
Temperature	Cold to the touch in winter	Neutral
Hooded options	Fewer; usually open or with a plastic lid	Wide range
Rust	Not with 304-grade steel; cheaper grades can spot	N/A

On smell and hygiene, steel wins clearly. On price and choice of shape, plastic still has the edge. For most single and multi-cat homes, the extra outlay on a steel tray pays back by not needing replacement and not needing a scented litter to mask the tray.

What to look for in a stainless steel cat litter box

1. Grade of steel. 304 stainless (sometimes labelled 18/8) resists rust and ammonia. Cheaper 201 steel can spot over time, especially where the finish is scratched.
2. Rolled or folded edges. Raw-cut steel edges are sharp. Rolled edges are safe for paws and hands and don't collect litter.
3. Depth. 12–15cm for most cats; 18cm or more for diggers and sprayers. A high back wall or a clip-on splash guard helps with cats that stand to urinate.
4. Size. The tray should be at least one and a half times your cat's length, nose to tail base. For an average cat that's around 55–60cm long. Large breeds need 65cm or more.
5. Non-slip feet. Steel on laminate or tile slides when the cat jumps in. Rubber feet or a silicone mat fix it.
6. Seamless base. A tray pressed from one sheet has no welded corners for waste to collect in.

Browse our cat litter boxes and trays to compare steel and plastic options by size and depth.

Cleaning a steel tray properly

Steel makes cleaning simpler, not optional.

• Daily: scoop clumps and solids. Use a metal or sturdy plastic scoop; it won't damage steel.
• Weekly: empty, wash with hot water and a mild unscented washing-up liquid, rinse and dry fully before refilling. Steel dries fast.
• Monthly or after illness: disinfect with a pet-safe disinfectant, or a 1:10 white vinegar and water solution left for ten minutes, then rinse. Never use bleach on a tray a cat will use within the hour; the smell of chlorine resembles urine to a cat and can prompt them to mark over it.
• Avoid: abrasive scourers on brushed finishes, which dull the surface. A soft brush is enough.

Will my cat use a steel tray?

Most do, without any transition. A few points help.

• Keep the same litter and the same depth of litter (5–7cm) as before, so the only change is the tray.
• Put the new tray in the old tray's exact position.
• In a cold room, the steel can be cold underfoot in winter. A thin layer of litter covers this; if your cat hesitates, a silicone mat under the tray reduces the chill from the floor.
• Noise: litter on steel sounds different when a cat digs. Nearly all cats ignore it, but a nervous cat may need the old tray left alongside for a week.

If your cat suddenly stops using any tray, steel or plastic, see your vet before changing equipment. Urinary problems are common in cats and toileting outside the box is often the first sign.

Mistakes to avoid

• Buying an unbranded tray with no steel grade stated. If it rusts, it's worse than plastic.
• Choosing a shallow tray for a digger. Steel won't stop litter going over a 10cm wall.
• Using a scented litter to cover tray smell. Fix the tray; most cats prefer unscented litter.
• Dropping to one tray because it's bigger. Two cats still need two trays plus one, whatever they're made of. See our guide on how many litter trays you need.
• Expecting steel to fix a position problem. A tray next to the food bowls or the washing machine will be avoided whatever the material.

Stainless steel cat litter box FAQs

Does a stainless steel litter box really smell less?

Yes. Steel doesn't absorb urine or hold scratches the way plastic does, so once washed, it's genuinely odour-free. The litter itself still needs scooping daily.

Will a stainless steel litter tray rust?

Not if it's 304-grade steel and dried after washing. Lower grades can spot where scratched.

Is steel too cold for cats?

A normal depth of litter insulates the base. Cats in unheated utility rooms may appreciate a mat under the tray.

How often should I replace a plastic litter tray?

Every 12 months as a general rule, or sooner if it smells when empty. A steel tray lasts for years.

Ready to make the switch? Browse our litter boxes and trays, including rolled-edge stainless steel and high-sided options, or see our self-cleaning litter boxes if scooping is the real problem. Free tracked UK delivery on every order and 30-day returns on unused items.