The Best Bath Toys That Don't Trap Mold: Four You Can Open, Drain or Wash

The rubber duck is the problem. Not the shape, and not the color, but the small hole underneath. A squeeze toy pulls bath water in through that hole, holds it in a sealed shell that never fully dries, and squirts it back out at a child's face a day or a week later.

There is now a careful answer to what grows in there. In 2018 researchers from Eawag, the Swiss federal water research institute, ETH Zurich and the University of Illinois published a study in npj Biofilms and Microbiomes that opened 19 bath toys used in real homes, plus six identical new toys run for 11 weeks under controlled conditions. Every single toy had a biofilm on its inner surface. Fungi turned up in 11 of the 19 real toys. In total, 80 percent of the toys tested positive for at least one indicator organism or potential opportunistic pathogen, and Pseudomonas aeruginosa was found in 61 percent of the real ones.

So the four picks below are chosen on one question first: can you get the water out, and can you reach the inside to clean it? One of them answers that less well than the other three, and its card says so.

What the study found, and what it did not

The useful part of the Eawag paper is its explanation of why the inside of a bath toy grows anything at all. The authors name four inputs: organic carbon leaching out of the flexible plastic itself, the bacteria already present in tap water, nutrients added to the bath by soap, shampoo and the bather's own body, and bacteria carried in from dirt and skin.

Bath toys, the paper notes, are mostly made from flexible PVC or silicone rubber, and flexible plastics are known for leaching carbon that bacteria feed on. The controlled half of the study then made the water the variable. Toys exposed only to clean water still grew a biofilm, but a thinner one, and none grew fungi. Toys exposed to dirty bath water carried more than ten times the bacterial density, with fungi in every case.

That points straight at the design question. A toy that seals bath water inside a soft shell is giving the biofilm exactly what it needs. A toy that drains completely, or comes apart so the inside can dry and be washed, takes most of that away.

What the paper does not say matters just as much. The authors are explicit that environmental exposure to bacteria and fungi "is not necessarily bad for human health and may indeed even strengthen the immune defense." They also cite earlier clinical evidence, including a 1998 report in the Pediatric Infectious Disease Journal that linked a multidrug-resistant Pseudomonas outbreak on a pediatric oncology ward to shared bath toys. That was a hospital, with children whose immune systems were already compromised. It is a reason to keep bath toys clean, not proof that a moldy duck makes a healthy toddler ill. Anything about a specific child's health is a question for that child's pediatrician.

How these four were picked

It opens, drains completely, or has nothing sealed. That rules out almost every classic squirter, because a sealed body with one small hole cannot be emptied or inspected.

Rigid or cleanable material. Two of the picks are hard recycled plastic rather than a squeezable shell. The other two are a pipe set that drains through open ends and a silicone toy that separates into halves.

Cleaning stated by the maker. Every cleaning claim below comes from the manufacturer's own product page.

Graded for the age it is sold to. Bath toys sit inside federal small-parts law. 16 CFR Part 1501, the rule that bans small parts in toys for children under three, lists "bathtub, wading pool and sand toys" and "squeeze toys" by name among the products it covers. Separately, 16 CFR Part 1250 makes the toy safety standard ASTM F963-23 mandatory for every toy sold in the US. Read the age grade before the picture on the front. How the small-parts test works and where it stops is set out in choking hazards in toys.

The picks

The comparison, in one table

Toy	Price	Opens or drains	Dishwasher	Squeezes
Green Toys Submarine	$13.06	Cabin opens	Yes	No
Ubbi Interchangeable, set of 4	$12.99	Splits into halves	Top rack	Yes
Boon PIPES, 5 pieces	$16.33	Open tubes	Not stated	No
Green Toys Tugboat	$17.99	Drains via spout	Yes	No

Who each one is wrong for

The submarine is wrong for a toddler whose favorite bath game is squirting a parent. It pours and sinks, but it does not squirt.

Ubbi's set is wrong for a household that will not take the halves apart after bath time. Its whole advantage depends on that step.

PIPES are wrong under a year and wrong on textured walls. Both limits come straight from the age grade and the suction design.

The tugboat is wrong for the parent who wants to see inside every toy. It drains well, but its hull stays closed.

Why the classic squeeze toy is not here

Nothing on this list is a sealed squirter, and that is deliberate rather than an oversight. Plenty of brands now sell "mold-free" squeeze toys, and some of them are sealed with no hole at all, which solves the problem by removing the squirt. Others call themselves mold-resistant while keeping a small hole and a closed body. Neither phrase tells a buyer whether the inside can be reached, and the Eawag study found a biofilm inside every toy it opened.

If a sealed squeeze toy is already in the house, squeeze it out completely after every bath, dry it hole-down, and replace it when the water it squirts is no longer clear. Neither step reaches the inside, which is the reason for the picks above.

Keeping any bath toy clean

Follow the maker's instruction, which on all four picks starts the same way: get the water out before the toy is put away. Stand toys open-side down in a ventilated spot, not in a closed bag.

Wash weekly on the schedule the maker allows. That means the dishwasher top rack for the Ubbi set, the dishwasher for both Green Toys boats, and a bottle brush and hot soapy water for the PIPES.

Look before you hand it over. A toy that has cracked, split at a seam, or will no longer snap firmly together has left the condition it was tested in. That matters for choking as much as for hygiene, for the reasons in choking hazards in toys.

Where bath toys fit in the first years

Pouring, filling and emptying is the containers stage that arrives around nine months, which is why stacking cups double as the best-value bath toy there is. What a baby can do month by month is in toys by development stage, and the toys that earn floor space outside the bath are in the best first toys.

No toy makes a child smarter, in the bath or anywhere else. The evidence on that, and on what does matter in play, is in do developmental toys do anything. For a baby still mouthing everything, a dedicated teething toy is the better thing to hand over, and the same one-piece, nothing-sealed rule decides which ones are worth buying.

Questions people actually ask

Is the black stuff inside a bath toy actually mold?

Often it is a mix. The 2018 Eawag study found a bacterial biofilm on the inner surface of every bath toy it examined, and fungi in 11 of the 19 toys that had been used in real homes. The black film most parents see is that combination of bacteria and fungi living on the plastic.

Is a moldy bath toy dangerous for a toddler?

The study's own authors say environmental exposure to bacteria and fungi is not necessarily bad for health and may even strengthen immune defense. Clinical problems have been documented mainly in hospital settings with vulnerable children. It is still a good reason to keep toys clean, and any concern about a specific child belongs with their pediatrician.

Are silicone bath toys mold-proof?

No material is. The Eawag paper notes that most bath toys are made from flexible PVC or silicone rubber, and both can carry a biofilm. What helps is a design that lets the toy drain, dry and be washed inside.

Do bath toys have to meet a safety standard?

Yes. 16 CFR Part 1250 makes ASTM F963-23 mandatory for toys sold in the US, and 16 CFR Part 1501 names bathtub toys and squeeze toys among the products covered by the small-parts ban for children under three.

Sources

• Neu, L., Bänziger, C., Proctor, C. R., Zhang, Y., Liu, W.-T., and Hammes, F., Ugly ducklings: the dark side of plastic materials in contact with potable water, npj Biofilms and Microbiomes, 2018, 4, 7
• Eawag, The ugly ducklings: biofilms in bath toys
• CPSC, CPSC Warns of In-Home Drowning Dangers with Bathtubs, Bath Seats, Buckets (release 10-008)
• CPSC, CPSC Report Highlights Persistent Risk of Childhood Drowning (release 26-572)
• eCFR, 16 CFR Part 1501, Method for Identifying Toys and Other Articles Intended for Use by Children Under 3 Years of Age Which Present Choking, Aspiration, or Ingestion Hazards Because of Small Parts
• eCFR, 16 CFR Part 1250, Safety Standard Mandating ASTM F963 for Toys
• Green Toys, Submarine
• Green Toys, Tugboat
• Ubbi, Interchangeable Bath Toys
• Boon, PIPES Building Bath Toy Set