Call us if you have any questions: 01299 823223

The Cot Mattress Company Ltd.

The UK's Leading Baby Mattress Specialist

Advice When Buying A Moses Basket, Crib, Cot or Cot Bed Mattress:
;Helpline 01299 823 223 ..............

Advice when buying a baby cot mattress

Your Moses, Crib or Cot and Cot Bed Mattress Buying Guide

Every day newborn babies sleep for an average of 16 hours and children of 3-5 years for an average of 11-13 hours. Babies and young children spend more than half of the first five years of life in a sleep environment; it is also the one place where they are most commonly left unattended for long periods of time.

The decision you make when buying a mattress for your child is vital. It must be safe, comfortable, supportive, and easy to keep clean, durable and comply with British Standards.

With such a choice on the market plus all the conflicting advice you will be bombarded with regarding cot deaths and chemicals it can make choosing a baby mattress very difficult.

Here are all the facts and advice you need to help you make an informed choice, come to a buying decision about the right mattress for you and your baby.  Find 25 minutes, Put the kettle on for a cup of your favourite brew and perhaps a favourite munchie and enjoy reading through our Baby Mattress Buying Guide, We hope it will help decide on the perfect mattress for you and your baby  .

What I Need From My Moses basket, Crib or Pram Mattresses ( Foam or Natural)

These  Moses or Crib mattresses will not be in use for very long, a few months, they do not need the same durability as cot mattresses but it is important that they can be kept clean, are comfortable and supportive and fully breathable.

First lets talk man-made foam, A minimum is a CMHR28 foam pad which is 3cm deep and a cover that can removed completely so the foam pad can be washed or the foam pad has waterproof protection and can be wiped down, but it still needs a breathable cover.

Best is a foam pad with a removable machine washable cover that is breathable (a spare cover is a good idea one for the wash) Moses basket  and Crib mattresses are also available in 5cm depths made with 33CMHR and 50 CMHR foam and even with pocket springs these mattresses are very luxurious extremely supportive have waterproof protection and do give a feeling your baby is lying in luxury.

Probably in a Moses basket mattress that will be used for 3 months, 5cm depth is an extravagance. However for a crib mattress lasting up to 6 months and a heavier baby 5cm is a consideration. The covers that go with these mattresses tend to be of the highest quality, and  these 5cm crib mattresses do not dent or dip and can be used for your next baby (we will discuss this  later before you say you have heard "new baby new mattress"!)

Now lets move on to natural mattresses instead of foam, coir is used as a base, it achieves its luxury feel by lining it with lambswool. Then comes the Moses Basket mattress cover, this has to offer waterproof protection as you cant wash coir and lambswool pads out as you can foam, Consider natural Outlux as a cover, this will give you the protection you need. Outlux fabric and its advantages are discussed in some detail later.

What I Need From My Cot Or Cot bed Mattresses

 A cot mattress will be in use for up to two years and a cot bed mattress could be in use for up to 5 years. Obviously we all have different amounts available to spend on a mattress and it will come down to cost, but there are basics that are needed, the cot mattress needs to be supportive, breathable and durable, the cot mattress core needs waterproof protection. .... More details to follow on this.


Is It The Thicker The Better? The Moses Basket, Crib, Cot or Cot Bed Mattress 

Not necessarily, In mattresses like most other things, quality is more important than quantity, however certainly avoid cheap 7cm foam mattresses unless you are using them for occasional use.

Look for quality dent resistant foam. Foam is measured in "kilo weight", the industry standard is CMHR28, most high street stores will offer this standard.  We suggest going no lower than CMHR28. Look for this specification when buying a mattress. Also available is CMHR33kilo and also we do supply CMHR50 kilo foam for "The Excellence" range of cot and cot bed mattresses’. This 50CMHR foam supported by pocket springs it will not dip or dent and extends the life of your mattress. More details to follow on this.

The British Standard for baby mattresses currently states that no mattress should be over 10cm in depth, for safety reasons to do with your baby climbing out of the cot.


My Moses Basket, Crib, Cot or Cot Bed Mattress Had A Chemical Smell When It Arrived - Is It Safe?

Advice when buying a baby  mattress

Foam is a man-made petroleum based product and when brand new will have a  chemical smell to it. The chemical smell of new foam happens because the foam has to release the component chemicals used in its manufacture. The ventilation of the mattress is a process known as 'airing'  or 'off-gassing'. Every petrochemical based foam product will need to 'off-gas' to get rid of the new smell.

Cot mattress manufacturers will&;try to leave the foam as long as possible in the factory before cutting it to let it air. However the foam arrives in massive blocks the size of a small room and the foam in the middle will take longer to air than the foam on the outside. If it is cut into small components and left for too long it has an opportunity to oxidise, (go yellow), or get contaminated. Manufacturers are reluctant to do this. If your mattress is cut from the outside of the block it is probably fully aired. If the foam used is from the inside of the block it might need airing longer.  When your mattress is made it is sealed immediately in plastic to keep it clean and hygienic.This will trap any air until you open the bag. 

 You can mask the smell - use Fabreeze or talc, but it is not really worth doing. Just leave it to air for 24- 72 hours in a well ventelated room or outside in the garden on a dry day and the newness smell will go.

You will notice reviews from every cot mattress retailer without exception that say:- “ When I opened my mattress it had a dreadful smell I would not put my baby in it”  This is understandable - everybody wants the best, safest mattress for their baby and does not want to put them on a toxic product. However this is a characteristic of the mattress. Foam is probably one of  the most widely used, safest man-made products you can buy! Let it Air in a very well ventilated room or outdoors and all will be well. You may comment that you have bought furniture or cushions that have not smelt. Simple answer:- they have been sitting in the shops for weeks or months and will have times to air.

I write this next paragraph with the greatest respect:- one can get paranoid about the smell and it is possible to always detect a hit of petroleum aroma if you unzip the cover and bury your nose in the foam! However as a test you should not be able to smell any toxic smell from 20 cm away with the cover on.
If you buy a natural mattress this will not have such a newness smell, there are no petroleum based chemicals used in natural mattre ses but synthetics do have some advantages over natural products when it comes to breathability and waterproof protection which we do cover further in this guide.

Waterproof Protection, The Toxic Gas Theory And Cot Mattress Wrapping.

This all kicked off in the late 80’s and was claimed it was the cause of cot deaths. It was later discredited by a government report, however a few people still claim that toxic gases can be present if urine comes into contact with the fire retardant components within the foam. When these gases are breathed or absorbed by a sleeping baby they can cause cot death or sudden infant death syndrome (SIDS). These claims have NOT been scientifically proven, NOR totally disproven "some would say" by the government report.

The supporters of this theory claim that if bodily fluids reach the foam mattress core and are left for a period of time, (over 3 months) then they react with the fire retardant chemicals in the mattress and this may cause a gas called Stibine gas to be produced, Stibine gas is highly toxic.

There are all sorts of scary things to read on the internet about cot mattress wrapping, you may have already read some of these!. Basically for piece of mind just prevent body fluids from getting to the foam.  But dont do it in a way that affects the breathabilty of the cover or you risk your baby overheating! Protect the cot mattress under the cover (over the foam). When you buy a cot mattress ensure it has full waterproof protection. Many cot mattresses are  made to hit a price point, they wont have any  protection and some will have just  a slider that covers only one third of the mattress which you have to position under the nappy area but your baby when it is older will move around the cot so this will not be adequate.

We developed the Safeguard range of crib and Moses basket mattresses to combat the fears of mattress wrapping. These mattresses have a completely sealed foam core that no gas could get through and no liquids could penetrate. Having a sealed mattress means maximum breathability must be maintained by the cover. This can be achieved by using a Microfibre or Coolmax and Maxi-Space cover which is fitted to the Safeguard Moses and crib mattresses.  All NightyNite cot mattresses have full protection, (they would, wouldn’t they!)


So this is key:- "It Is of Paramount Importance To Prevent Bodily Fluids Getting To The Core Of The Mattress And Still Keeping The  Mattress Breathable."

Advice on buying the best mattress for your baby

One way to achieve this is on a cot or cot bed mattress is to choose a fabric that is breathable like Microfibre or Coolmax with Maxispace, then protect the core under the cover to keep the body fluids away from the foam core. Do this by ensuring your mattress has a full PU band around it covering at least 90% of the mattress centre or a full Safetex cover as in the Easychange range with zip off machine washable toppers   

 If you buy a waterproof protector for your mattress consider NOT putting it on the very top of your mattress. Remove the cover and put it over the core, it is the core you want to protect from body fluids, then put the mattress cover on top, the cover will hold air over the waterproof protector and help to avoid your baby overheating. If the cover gets soiled then easy to remove for washing and then wipe down or wash the protector if fluids have gone through. Spare covers are a great idea. Many mattress protectors say they are breathable but if you hold them to your mouth and try and suck air through you will see they are not breathable at all. They past a breathability test because if you held a boiling kettle on one side you can steam up a mirror on the other side, so they are classed as water vapour permeable. However if your baby turnd face down on it, it would not get enough air through to breath normally.

Another option is the NightyNite™ Easychange range of cot and cot bed mattresses, these have a top that zips off completely from the rest of the cover and hold the air, and the underneath main cover is completely waterproof. This allows you to zip on whatever sleep surface you wish for maximum breathability and comfort.  Stop Press... there is now an even better solution we won an award in 2016 for our Excellence Supreme this gives a wipe clean base cover under a breathable topper.

Cot matttress Metal Spring Scare

In 2009 we heard of a report regarding the possible negative effects of an electromagnetic field on babies, the report said it is especially important for you to use a non-metallic bed for your baby, as their immature bodies are more susceptible to EMF damage. As with most of these scares they are never proven, but they manage sometimes to pose yet another question when choosing a  baby mattress. 

Terminology Explained

Micro Climate

A term used to explain what occurs when you use a fabric like  Coolmax with Maxi-Space. These fabrics allow a much better airflow around the body which helps to reduce heat and sweating and increases the breathability. The Nightynite® Excellence Easychange or the Nightynite® Reassurance Easychange® comes out tops here.

Coolmax, Outlast, Thermosleep

These are specially engineered polyester fabrics that wick away heat from the body and regulate temperature, when combined with quilting they have a luxury soft feel. The best effect by far is achieved by not quilting but backing them with a quality 3D spacer fabric like Spacetec or Maxispace. As well as adding luxury to the Coolmax© or Outlast they also allow thousands of cells where the heat can be wicked away. Another way to help wick away heat and more naturally is using bamboo. Bamboo is a luxuriously soft material, softer than cotton with natural temperature regulating properties. There is now available a range of 100% bamboo sheets which can be fitted to any cot, crib or Moses basket mattress. Fitting 100% bamboo sheets over Coolmax with Maxispace would be indeed the height of luxury.

British Standards

Every mattress sold in the UK should conform to British standards; BS7177 and BS1877, these relate to quality of filling and flammability. to be honest we cant see any manufacturer of baby mattress not adhering to these standards.


This basically means non-allergy producing. Most mattress retailers, (ok and us) use this a sales pitch, but it means nothing if you do not keep your mattress covers and mattress core clean.

Cot Mattress Sizing Guide

This is all about the gap left between the side of the mattress and the side of the cot, too big and there is a risk of trapping of limbs in the night. The ideal situation is a mattress that presses right up against the side of the cot or cot bed, but there has to be a small gap to allow the use of the drop side. The maximum gap allowed by EU regulations is now 3cm, that’s 1.5cm all the way round the mattress. Used to be 2 inches (5cm), then with EU Regulations went to 4cm now it is going to 3cm - Keeps somebody in the EU a job!

There are some main popular sizes of cot and cot bed mattress: 117 x 54cm, 120 x 60cm, 127 x 64cm, 126.5x 62.3 (M and P 300 size) 130 x 70 and the most popular which is 140 x 70cm (often referred to as 139x 69cm)

Less popular sizes are:

112 x 55cm, 122 x 61cm,131 x 71cm and 132 x 77cm. the last two pertain to the Boori range of cots.

Synthetic Mattresses Explained

Synthetic materials (petroleum based) and make up 90% of the total mattresses sold in the UK (the rest being natural mattresses, explained below)

Covers For Moses basket, Crib, Cot or Cot Bed Mattresses

They are designed with several tasks in mind; breathability, waterproofing, comfort, temperature regulation, durability and hygiene.

Covers can be made up of different layers to perform these tasks, a cover could be made of a material which is thick enough to generate its own breathability (micro-climate) and have a waterproof lining underneath to protect the core. It is important to prevent bodily fluids from reaching the core and breeding bacteria or reacting with the synthetic products used.

There is also a question over PVC being carcinogenic, PVC and PU will not breathe and if used on their own will prevent airflow and cause overheating. We recommend having an external cover with quilting or spacer fabric that will promote airflow and insist on PU or woven waterproof protection underneath. All Nightynite® mattresses have some sort of breathability and waterproof protection in place!

Synthetic mattress covers can be washed at 60 degrees, which is the temperature needed to kill dust mites and bacteria.

As with all brand new products they may have a crisp new feel to them but a first  washing with restore a softer feel and removed any newness smell to them

Waterproof Sliders/ Membranes

These are waterproof bands that go under the cover and around the mattress core to protect the core from spillages, the reason they are not around the whole mattress is that they would reduce breathability. That was the old thinking now we have moved on. Waterproof liners covering at least 90% of the foam area under the cover and the cover being fully breathable.  


Foam used in the UK has to be fire retardant, that is the law. It has to conform to BS1877 and BS7177. The Foundation for the Study of Infant Deaths (FSIDS) now renamed "The Lullaby Trust" do not approve of this fire retardant being achieved by using phosphates, they prefer melamine, however melamine makes the foam weaker and more susceptible to breakdown i.e. dipping and denting .

The only way to fulfil the needs of FSIDS and the UK law is to use CMHR foam (Combustion Modified High Resilience)

The problem with using CMHR foam is you have to use a much higher grade to get the durability. All reputable retailers high street stores will use CMHR28 as a standard this will give support and is long lasting if the mattress is rotated frequently to allow the foam to recover.  The heavier the grade of foam the more support and the less it will indent or dip.  

Consider this:-   Foam as a product does not like heat weight and damp exactly what a baby is! This is what makes foam dip and dent and break down, the initial weight on the mattress is taken by the foam before pressure is put on the springs below.  If you have a higher grade of foam it will be more durable. Many years ago and we developed THE EXCELLENCE" a cot mattress with CMHR50 (50 kilo foam). This foam will not dent or dip and give many years of support.  CMHR50 foam is more supportive and firm and mattresses using this foam will have luxury covers to give a soft initial lie.

All of Europe other than the UK uses a continental foam, they believe their foam is safe and it is stronger due to not using Melamine for fire retardant. Some UK companies are going back to RX foam which is flame retardant but do not use melamine to achieve this. Some international companies selling their mattresses here will use it as well, but FSIDS (Lullaby trust) do not actually recommend it)

Memory Foam

While it does feel soft and has a great reputation on adult mattresses it is not ideal for baby mattresses. Memory Foam has more chemicals, creates more heat and also creates pooling of carbon dioxide. Some companies have used it for baby mattresses. We have researched it and we would certainly not use or recommend it for baby mattresses.

Fibre baby Mattresses
 Fibre is used as a cost cutting exercise and a marketing means to say "FOAM  FREE". The problem with fibre is that it is not as strong as foam, not as durable, wont last as long and will not give the support unless you increase the fibre quality then you are alnost at the same price as foam. There are only a few foam converters in the country  and they do hold foam users over a barrel when it comes to price, that is a main reason why manufacturers are turning to fibre as an alternative.  

Coir and latex

These are natural products but they can be used with synthetic components for example coir with springs. Latex is expensive and generally only used with natural products. The downside with latex is that some people are allergic to it, it does create heat so you have to perforate it then it loses some of its strength and it can have a fusty smell that takes a little while to dissipate.


Springs are excellent to have in a mattress to increase support and airflow by allowing air to flow in and around the springs.

We use two main types of springs;

Mini Bonnel Springs used in Cot or Cot Bed Mattress

These are the sprung units and offer the baby excellent support and prevent the mattress feeling like an uncomfortable brick of foam they also reduce the heat build up in the foam by making a large space of air.

Pocket Springs used in  Crib, Cot or Cot Bed Mattresses

These are more supportive and comfortable than mini bonnel springs. Individual springs that work independently to target the different pressure points of the child’s body, allowing better support for the head, back neck and legs. The only disadvantage of the pocket springs is that they are a little more expensive than their mini bonnel counterpart. Smaller pocket springs can be used for crib mattresses as these have a maximum depth of 5cm

Natural mattresses explained

Advice on buying a natural mattress for your baby

Natural mattresses are made from all natural components with no man made parts used, they account for 6% of the total mattresses sold in the UK. but the figure is growing 

Natural cot mattresses use coir and lambswool mostly and  some use latex. Pocket springs can be  added to coir and Lambswool to give extra duribuility and the mattresses then promoted as natural because it does not have foam in - a debateable point.  

All baby mattresses sold in the UK have to conform to strict British standards to ensure they are safe and non-toxic. Foam, synthetic fabrics and springs are used extensively throughout millions of everyday products. These components may be able to offer better durability, temperature regulation, breathability etc but natural mattresses using organic components have these features naturally built in.


These are mostly cotton made of different density and weaves, and if they are claimed to be organic then the area where the cotton comes from has to be approved by an authority to be organic. These covers are not normally waterproof and that has been a concern with parents, the one drawback to a natural cover. Some of these covers have been made waterproof by using a minute layer of treated fibre sandwiched in the middle of the cover, they are also washable at 60 degrees and because of the tiny amount of synthetic quantity they can be called a natural product. We use this type of waterproofing on our Natural Start mattress range and our Natural Supreme cot and cot bed mattress. The fabric we use is called Outlux it is one of these three layered fabrics:-  two layers of soft brushed cotton and in the middle a tiny thin layer of PU to give it its waterproofing properties.


The core is normally made from coir which is very firm, either side of the coir is generally wool to give the coir a softer feel. The wool can be treated with various natural products like eucalyptus, lavender etc to give it extra properties. We use coir in our Natural Start and Natural Supreme mattresses.

The downside of  natural mattresses  is the that the cotton covers with waterproof fillament in  are not as breathable as the man made covers, the  waterproof membrane sandwiched in them  restricts the airflow. If you have cotton covers without the waterproof protection then the mattress core will get soiled (you cant have everything).  However speaking to parents who go for coir and lambswool they do so because foam is the enemy.  So we have made mattresses with coir and lambswool  as a base so it is non foam  Non-foam core then fitted  the Easychange microfibre or Coolmax and Maxispace covers.  We also make the core with pocket springs coir and lambswool (NO FOAM)  and then fit the Easychange microfibre or Coolmax and Maxispace covers. give us a ring on 01299 823 223 if you want us to do that for you. we will soon have this liste don our site as an option.   

How Did You Get On?

Having read all of the above we have hopefully given you an extensive knowledge of baby mattresses and you are more able to make an informed buying decision on your choice of mattress.  Should you still have questions please call us on 01299 823223 or email us on We get lots of calls every day, we would be pleased to hear from you. Your questions  helps us amend our buying guide  just in case if we have missed some very relevant information.