Tommee Tippee Electric Steam Steriliser – A serious health risk?

230653167This review is in the category of “Manufacturer Fail”. This product is so badly designed it actually appears to represent a health risk!

You will find many complaints about this product on the web from consumers that have products that break down and require replacement, and then find those products also break down. – I am one of these consumers –

This product is designed to make is easy for parents to quickly sterilise baby feeding bottles.

The product brief is as follows:

The new Electric Steam Steriliser has all the streamlined looks and style of its top-selling predecessor but has a host of brilliant new features to make it stand out from the crowd. There’s a new sleek and clean-looking oval shape to mimic the shape of the Closer to Nature bottle and take up less space on the kitchen workbench. There’s a space for everything inside … purpose-built slots for six bottles, teats and even dome tops as well as space for the tube attachments from the Closer to Nature anti-colic pus bottles. There’s a single push button which glows orange when switched on and goes off when the cycle is finished five minutes later (allow three minutes to cool down). And as if that’s not enough, the steriliser contents now stay sterile for a full 24 hours provided the lid remains closed, giving parents the chance to switch it on at bedtime – and remove clean bottles at breakfast time.

This product almost always operates as intended when brand new and out of the box — but after several weeks or months, the unit starts to break down…. secretly!

How can a product secretly break down? For that answer you need to understand a little bit about how it works.

Firstly, cleaned bottles are placed within the unit with a specific quantity of water. When powered on, a heating element turns some of this water into steam within the unit. This steam thermally sterlises the bottles and after eight minutes the bottles are ready for use and remain “sterile” for 24 hours.

A normal cycle is about four minutes “ramp up” and one minute “soak”. The last three minutes are to cool down.

The common fault of these units is the sterilising cycle lasts for less than the full eight minutes. Users report cycles of 30 seconds to 2 minutes before the unit has “finished”.

I became aware of this issue when my child started to experience tummy upsets and started to investigate the cause. After exhausting all avenues like spoiled milk, colic, lactose intolerance etc I noticed an unpleasant odour from his bottles.

After “sniffing around” I discovered the inside of the sterliser also smelt very “off” as though it contained stagnant water. (Clean water is always used each time the unit is used)

Normally we sterlise our bottles at night before bed so they are ready for use the next morning (as per Tommee Tippee’s advertising). To find out what was going on I ran the cycle after ensuring the unit was fully de-scaled and clean.

To my surprise the unit finished it’s cycle after only 90 seconds! I was shocked when I realised that the bottles could not possibly have been fully sterilised after this time so I decided to conduct further tests to see what could possibly be going wrong.

I connected my data-logger and placed two thermocouples within the unit to log and graph the temperature profile. After running sterilising cycle again, I evaluated the results.

From room temperature the unit ramped up to 44°C before the unit completed the cycle. This temperature – will not – kill bacteria. What makes the matter worse is that the “cool down” period keeps the bottles at a harmful temperature much longer than I expected. From 44°C it took 55 minutes to reach room temperature within the unit. (Room temperature being 21 degrees C in my kitchen at the time).

The implications of this only make matters worse. Bacteria – love – wet and warm places to grow, breed and defecate.

Bacteria divide rapidly at 27°C to 41°C. In ideal conditions (i.e. in most environment at 37°C) bacteria will grow and multiply by dividing into two every 20 minutes. After 6 hours, in ideal conditions, one bacterial cell could become 131,072 bacteria.

At a temperature of about 37°C (human body temperature) pathogens multiply most quickly but as the temperature continues to rise, their rate slows down and they will stop growing altogether above 63°C. However, in order to destroy bacteria, temperatures must rise further. A temperature of 70°C for 2 minutes is recommended as a means of killing pathogens.

At this point I wanted to do nothing more than return the unit with a very strongly worded letter to Tommee Tippee.

Instead I decided to do a comparison of the microbial contamination of a bottle left within the steriliser with a bottle left on my kitchen sink drainer. A sample was taken from each bottle at the start of the test and after 24 hours. The samples were then analysed and the shocking result is that the bottle within the sterliser had – five times – more microbial contamination than the bottle that was left on the drainer. Turns out it is far worse to use the sterliser than not at all.

Now of course these are not clean-room lab tests so additional sources of contamination should not be ruled out. I could grow cultures from both bottles and establish the exact bacteria involved but I think this would only strengthen the evidence against this product and should be something undertaken at Tommee Tippee’s expense.

Putting the health risks aside, I wanted to establish the root cause of this problem and understand how it could happen.

SAFETY WARNING: Do not attempt to make alterations to your Tommee Tippee sterliser. There is not a lot that can be done to service the unit yourself and you risk killing yourself either directly by electrocution or indirectly by burning your house down. Don’t take the risk!

Inside the unit there are very few components:

A heating element – which heats the water to boiling point
A neon indicator – to show the unit is powered
A resettable 250V AC thermostat by Keensound Industries (which was the faulty component)

And nothing else!

The way the unit works is by “cutting out” when the heating element reaches a target temperature. This can reset when the thermostat has cooled by pressing a button (which is the “Cycle Start” button).

I can understand the reasons behind the electrical thermostat, it prevents the unit boiling dry and possibly causing fire. The problem is that it does not measure the temperature of the water, nor steam and it does not operate for a specific duration. Should the thermal conductivity between the thermostat and the element change, so would the duration of the sterilising cycle.

This component should only be used as a safety measure or failsafe and not as the primary component to run the sterilising cycles.

The only way I can see the product not being a risk to infant health is to completely redesign the operation of this unit. By adding a few simple components such as a microcontroller, thermistor, SSR and a true status LED this would solve all of the problems I have mentioned and would not add any more than £1 – £2 to the overall cost of production. This would then allow the unit to provide clear feedback on the cleaning cycle so any consumer can be sure that it has in fact sterilised as expected.

My suggestion? Withdraw this product from market in its current form.


In my professional opinion, this product is a failure by design. Components used to prevent boilers overheating, or to set the temperature in a coffer maker are being used in a way they were never intended. Tommee Tippee themselves suggest discontinuing use if it appears the cycle is not completing. But how are you supposed to know? I have no idea how many infants could have become sick due to this product but in most cases I am sure it may have gone undiagnosed and put down to colic. I feel this product should not be on the market!

Had problems with this product yourself? I would love to hear your experiences and comments below.

I would also like to note that this was the second unit that we have owned which had the exact same fault. The first unit was purchased 18 months beforehand when we purchased one for our first child.

If you have this unit, please go and time it to ensure it’s running for the advertised cycle time.



It appears this problem is more widespread that I initially realised, confirming it’s a fault by design.

If you have one with this exact fault, please get in touch as I would be very happy to perform a thorough test on another unit to provide documentary evidence as a basis of legal proceedings. This has also been forwarded to BBC Watchdog with the hopes that it would be investigated further and force Jackel to take action.