Cot safety features: sleeping safely in a cot

Babies need lots of sleep, and during the first two years of their life they will on average spend more of their time sleeping than not. If your baby sleeps in a cot, you should definitely take cot safety into consideration. It’s worthwhile spending time choosing the right one for you and for them.

Choosing a cot

As well as considering the design and look, the cot you choose must conform to British safety standards (BSEN716). The reason for these safety standards is to reduce the number of accidental infant deaths each year due to strangulation or suffocation. The following guidelines have been developed to help when looking for a cot:

Cot frame

• Depth: the distance between the top of the mattress and the top of the cot sides should be at least 50cm, to prevent your baby from climbing out when they become more mobile.
• Cot bars should be vertical; if they are horizontal your baby could use them as a ladder to climb out. Also, the distance between the bars should be no more than 6.5cm apart so your baby can't get stuck between the bars of the cot.
• It is also recommended by some experts that a cot with bars on all four sides is better, as it allows air to circulate freely while your baby sleeps.
• If your cot has a solid head and footboard with shapes cut out, check that your baby’s limbs cannot become caught in any of the spaces.

Cot mattress

• The Lullaby Trust recommends you buy a new cot mattress, or - if using a second-hand mattress - carefully check that it's clean, dry and free from cracks or tears. Your cot mattress should be firm, with no sagging and fit the cot snugly, with no gaps.
• Mattresses tend to come in two sizes, standard and continental and should fit the equivalent sizes of cots commonly available in the UK.
• The mattress needs to be kept as clean and hygienic as possible. You can either use one with a wipe-clean covering or a removable top panel that you can wash at a high temperature. Alternatively, you could use a mattress protector, which covers the mattress to stop it getting wet if the baby dribbles or their nappy leaks.
• Choose a mattress that feels firm rather than soft, your baby needs support while they are sleeping. It should be no thinner than 8cm.
• Check it conforms to safety standards - mattresses should carry the BSI number BS 1877-10:2011+A1:2012.
• There are three main types of mattresses you can choose from: foam cot mattresses, spring-interior cot mattresses and coir cot mattresses. There are pros and cons to each of these. Do your research, test, touch and feel each type and decide what suits you and your family best.

Second hand cots

Although a great option for keeping down initial costs, you’ll need to make sure that it conforms to current safety standards, mentioned above. Furthermore:

• If it is a very old, painted cot, it may need to be stripped down and repainted. Cots made before 1973 could have used leaded paint, which is toxic.
• If it’s got a drop-side mechanism, it's best not to use the cot, as the mechanism could be unsafe now.
• If there are any stickers or transfers on the inside of the cot, remove them, as they may peel off and present a choking hazard.
• Check there is nothing sticking out of the top rail which may catch your baby’s clothes.
• Unless you know the history of the mattress, and have checked it for cleanliness and size, and are happy with it, it is recommended that you buy a new one.
• Check that there is nothing on the inside of the cot that your baby can use as a foothold to help them climb out.

(Sengölge and Vincenten, 2013)

Where to place the cot

Babies are less able to control their temperature so the cot shouldn’t be near a radiator or sunny window. Blind cords are also a risk as babies have been known to become entangled with these and strangled.

Inside the cot

The Lullaby Trust advises that the safest cot is a clear cot - clear from soft toys, cot bumpers, wedges or sleep positioners, for instance. This is because evidence shows that the safest way for a baby to sleep is on a firm flat mattress in a clear cot. 

Some items added to a cot may increase the risk of head-covering and can also increase the risk of accidents. This is due to the risk of suffocation and/or strangulation, as well as the chance that they could be used to climb on when your baby becomes more mobile.

Pillows and duvets aren’t safe for babies younger than one year due to the risk of suffocation. Duvets can also make the baby too hot.

Find out more about why a clear cot is the safest option.

Sudden Infant Death Syndrome (SIDS)

Babies who share the same room as their parents for the first six months or so have a lower risk of Sudden Infant Death Syndrome (SIDS), also known as cot death. Here are some guidelines which help towards cot death prevention and encourage safe sleep for your baby: lower the risk of this occurring:

• The room should not be too hot as babies who overheat are at an increased risk of SIDS. They can get too hot because the room is too hot, or because they have too much bedding or clothing. The ideal room temperature is between 16 and 20ºC.
• Babies should sleep on their back with their feet at the foot of the cot to stop them wriggling down under the covers.
• Babies should not sleep with electric blankets or hot water bottles, although, if you are worried about the cot being too cold you could use one that is removed before the baby goes in. As mentioned above duvets, bumpers and pillows are not recommended if your baby is under one year old.
• Your baby’s cot should not be close to a radiator or in a sunny position.

"The Department of Health and The Lullaby Trust say the safest place for your baby to sleep in the first six months is in a cot in your room".

However, many parents sleep with their baby in their bed; you can read about how to do so safely here.

This page was last reviewed in February 2018, amended December 2023.

Further information

Our support line offers practical and emotional support with feeding your baby and general enquiries for parents, members and volunteers: 0300 330 0700.

You might find attending one of our NCT New Baby courses helpful as they give you the opportunity to explore different approaches to important parenting issues with a qualified group leader and other new parents in your area.

The Department of Health has information on how to reduce the risk of cot death.

The Lullaby Trust has lots of useful information and support for parents about safe sleep.