Bath Toys With Holes: Why Mould Grows and What Parents Can Do

There is a particular parenting moment that is both fascinating and slightly horrifying.

You squeeze your child’s favourite bath duck, expecting a stream of water, and instead a few dark flakes appear in the bath.

At that point, most parents have the same questions:

• What is growing inside the toy?
• Can it be cleaned properly?
• Does every bath toy with a hole need to be thrown away?
• Are “mould-free” bath toys genuinely different?

The reassuring answer is that you do not need to panic or immediately replace every toy in your bathroom.

But toys that take water into a hidden cavity are more difficult to inspect, clean and dry than sealed or open-design toys. Understanding that difference can help you decide what to keep, what to clean and what to choose next time.

The Quick Answer: Are Bath Toys With Holes Safe?

A bath toy with a hole is not automatically dangerous. The problem is that the hole allows bath water to enter a dark internal space that may be difficult to drain and dry completely.

Over time, moisture, soap residue, body oils and other organic material can contribute to a biofilm forming inside the toy.

The Royal Children’s Hospital Melbourne advises that hollow bath toys or toys with holes can become mouldy. It recommends sealed toys that do not trap water, or carefully emptying and drying hollow toys after use.

The Raising Children Network also recommends choosing bath toys that do not trap water and can be cleaned easily.

So the practical answer is:

• Sealed, no-hole toys are generally easier to maintain.
• Open toys that drain completely can also be practical.
• Hollow squirting toys need more care and are harder to inspect internally.
• A toy that releases dark residue, smells unpleasant or cannot be dried properly should be replaced.

Why Does Mould Grow Inside Bath Toys?

Bath toys spend their lives in a warm, wet environment.

When a hollow toy is squeezed under water, bath water enters through its opening. Some of that water may remain inside after the bath, even when the toy has been squeezed several times.

The inside of the toy then offers several conditions that support microbial growth:

• persistent moisture
• warm temperatures
• limited airflow
• soap and cleanser residue
• skin cells and body oils
• organic material from the bath water

What parents commonly describe as “mould” may actually be a more complex biofilm containing bacteria, fungi and other microorganisms.

A study published in npj Biofilms and Microbiomes examined the internal surfaces of bath toys used in real homes and under controlled conditions. Researchers found substantial and varied microbial biofilms inside the toys they examined.

This does not mean that every bath toy will make a child sick. Microorganisms are present throughout our homes and environment, and the health significance depends on the organism, the amount of exposure and the child’s individual circumstances.

The practical concern is simpler: a hidden internal surface that cannot be seen or reached is difficult to clean with confidence.

Why Squirting Toys Are Particularly Difficult to Maintain

Squirting toys need an opening to draw in and release water. That feature is also what makes them difficult to keep dry.

You can squeeze water out after the bath, but it is hard to know whether:

• all the water has been removed
• residue remains on the internal wall
• the inside has dried completely
• there is mould in a section you cannot see

This is different from a stacking cup, open boat or pouring toy. An open toy might still become dirty, but you can usually see the whole surface, wash it and allow it to drain.

That visibility is one of the most useful features to consider when choosing bath toys.

Does “No Holes” Mean a Bath Toy Is Mould-Proof?

No toy should be assumed to be permanently mould-proof.

A sealed toy prevents bath water from entering a hidden hollow space, which removes one of the main areas where moisture can remain trapped. But the exterior can still collect soap residue, grime or surface mould if it is never cleaned or allowed to dry.

Rather than treating “mould-free” as an absolute guarantee, it is more useful to look for toys that are:

• sealed and manufactured without water-entry holes
• open enough to drain completely
• easy to inspect from every angle
• made without complicated joins or hidden spaces
• supported by clear cleaning instructions

Design is often more important than the material name alone.

How to Check the Bath Toys You Already Own

You do not need to discard every bath toy simply because it has been used in water.

Start with a simple inspection.

1. Look at the outside

Check for:

• black or coloured spots
• slimy residue
• cracks or splits
• peeling paint or damaged finishes
• parts that are becoming loose

2. Smell the toy

An unpleasant, damp or musty smell can indicate that water or residue has remained inside.

3. Squeeze hollow toys over a white basin

If a squirting toy releases cloudy water, dark flakes, slime or an unusual smell, it is sensible to stop using it.

4. Listen for trapped water

Shake the toy after you think it has been emptied. If you can still hear water moving inside and cannot remove it, the toy is unlikely to dry properly.

5. Check the toy’s condition

The ACCC Product Safety kids’ toys guide advises parents to regularly check toys for damage, brittleness, tearing and parts that may come loose.

A bath toy should be replaced if it has deteriorated to the point that pieces may break off or the toy can no longer be properly cleaned.

A Practical After-Bath Routine

The easiest cleaning routine is the one you can repeat consistently.

After each bath:

1. Remove the toys from the bath water.
2. Rinse off visible soap or bath product residue.
3. Drain open toys completely.
4. Squeeze as much water as possible from hollow toys.
5. Place toys somewhere they can dry with good airflow.
6. Do not leave them sitting in the bath or in a container filled with water.

A draining rack or open basket may work better than a closed storage box. The storage container itself also needs regular cleaning, because water and residue can collect underneath the toys.

Once a week, or as part of your normal bathroom clean, check the toys for residue, trapped water and damage.

How Should Bath Toys Be Deep-Cleaned?

There is no single cleaning method that is appropriate for every bath toy.

Bath toys may be made from natural rubber, silicone, conventional plastic, recycled plastic, bioplastic, wood, fabric or a combination of materials. Heat, soaking, dishwashers, disinfectants and sterilising solutions can affect those materials differently.

The safest starting point is always the manufacturer’s care instructions.

Depending on the product, the instructions may recommend:

• wiping with a damp cloth
• washing with mild soapy water
• rinsing and air-drying
• using a dishwasher
• avoiding soaking
• avoiding boiling or sterilising

Do not assume that a method is safe simply because it worked for a different toy.

For example, some natural rubber toys are designed to be wiped with mild soapy water rather than submerged or sterilised. Hello Charlie’s Oli & Carol Flo the Floatie is made without holes, but its care instructions still specify wiping it with soapy water, air-drying it and avoiding sterilisation.

If a toy has visible internal contamination that cannot be reached, cleaning the outside will not solve the problem inside. At that stage, replacement is generally the more practical option.

Should You Seal the Hole Yourself?

Some online advice suggests closing the hole in a squirting toy with glue.

This might appear to solve the water-entry problem, but modifying a baby or toddler toy introduces new questions:

• Is the adhesive suitable for a toy that may be mouthed?
• Could the seal loosen and become a small part?
• Was moisture already trapped inside before sealing?
• Does the modification affect the manufacturer’s intended design?

For these reasons, choosing a toy manufactured as a sealed design is preferable to modifying a toy at home.

What to Look for When Buying a Bath Toy

Choose the right design

Look for:

• sealed toys without water-entry holes
• open cups, boats or scoops that drain fully
• simple shapes without inaccessible joins
• surfaces that can be seen and cleaned

Check the age recommendation

Choose toys that are clearly labelled for your child’s age and development.

Australian mandatory standards apply to toys intended for children up to and including 36 months, particularly in relation to small parts and choking risks.

Check the construction

The toy should be sturdy enough to withstand being bitten, pulled, squeezed and dropped without breaking into small pieces.

Be cautious with foam toys for children under three

Both the ACCC and Raising Children Network advise against foam toys for children under three because a child may bite off a piece, creating a choking risk.

Read the care instructions before buying

A beautiful bath toy is not very practical if its cleaning requirements do not suit your family.

Before buying, check whether the toy:

• can be submerged
• can be washed in a dishwasher
• needs to be wiped only
• must be kept away from heat or sunlight
• requires regular inspection or replacement

Natural Rubber, Silicone or Plastic: Which Is Best?

No single material is automatically the best choice for every family.

The construction, manufacturer, care instructions and intended age are just as important as the material itself.

Natural rubber

Natural rubber is soft and flexible, which can make it useful for bath toys that also function as teethers or sensory toys.

Some natural rubber bath toys are manufactured as one-piece, no-hole designs. These avoid the hidden internal cavity associated with traditional squirting toys.

Natural rubber needs product-specific care. Some toys should not be boiled, sterilised, soaked or placed in a dishwasher.

Hello Charlie’s Tikiri collection includes natural rubber toys made without holes for water to enter. You can also read more about Oli & Carol natural rubber toys.

Silicone

Silicone can be flexible and durable, and it is often used for open bath cups, buckets and pouring toys.

Whether a silicone product is dishwasher-safe or heat-safe depends on its manufacturer, so check the individual instructions rather than assuming.

Recycled or conventional plastic

Well-made plastic toys can be durable and easy to clean, particularly when they have an open design that allows water to drain.

Stacking cups, boats, scoops and watering toys may be easier to inspect than hollow squirting animals.

The material itself does not prevent mould if the toy is continually left wet. Drainage and drying remain important.

What About Second-Hand Bath Toys?

Second-hand toys can reduce waste and extend the life of a product, but bath toys deserve a careful check before being passed on.

The ACCC recommends checking that a second-hand toy:

• has not been recalled
• meets relevant standards
• still has its safe-use instructions
• is in good working condition

A sealed or completely open toy that can be inspected and cleaned may be suitable to pass on.

A hollow toy with an inaccessible interior, trapped water or an uncertain history may be better retired.

Do Not Forget the Main Bath-Time Risk

Mould in bath toys is worth addressing, but it should not distract from the most serious bath-time safety issue: water.

Babies and young children need constant, active adult supervision in the bath. Keep everything you need within arm’s reach before the bath begins, and take your child with you if you need to leave the room.

Bath toys, bath seats and bath supports are never substitutes for supervision.

A Simple Bath Toy Checklist

Before buying or keeping a bath toy, ask:

• Can water enter a hidden cavity?
• Can the toy drain completely?
• Can I see and clean every wet surface?
• Is it suitable for my child’s age?
• Is it sturdy and free from loose parts?
• Are the cleaning instructions clear?
• Can it dry fully between baths?
• Would I notice quickly if it became dirty or damaged?

Frequently Asked Questions

Do I need to throw away every bath toy with a hole?

Not automatically. Inspect the toy, empty it after each use and follow its care instructions. If you cannot remove trapped water, see inside it or clean it with confidence, replacing it with a sealed or open-design toy may be the more practical choice.

What should I do if black pieces come out of a bath toy?

Stop using the toy. Dark residue, slime, cloudy water or an unpleasant smell can indicate internal build-up that cannot be adequately reached from the outside.

Can I put all bath toys in the dishwasher?

No. Only use a dishwasher when the manufacturer specifically says the toy is dishwasher-safe.

Can natural rubber bath toys be sterilised?

Not necessarily. Heat and sterilisation can damage some natural rubber products. Follow the instructions supplied with the individual toy.

Are sealed toys completely maintenance-free?

No. Sealed toys still need to be rinsed, cleaned, inspected and dried. Their advantage is that bath water cannot enter an inaccessible internal space.

How many bath toys does a child need?

Usually fewer than we think. A small rotation of easy-to-clean toys can provide plenty of play while making cleaning and drying much more manageable.

Final Thoughts

Bath toys should make family life easier and bath time more enjoyable.

You do not need to fear every rubber duck or create an elaborate disinfecting routine. The most useful change is simply to notice how a toy is designed.

If water can enter but cannot easily leave, the toy will be harder to inspect, clean and dry.

When replacing a worn or difficult-to-clean toy, look for a sealed no-hole design or an open toy that drains completely. Keep the collection small, follow the manufacturer’s care instructions and allow everything to dry between baths.

As with most sustainable parenting choices, progress matters more than perfection. Use what is still suitable, replace what is damaged or unhygienic, and make the next purchase a little more considered.

This article provides general product-care and parenting information only. Always follow the manufacturer’s instructions and age recommendations. Constant adult supervision is essential whenever babies and children are in or around water.