Breast milk can sit out for up to 6 hours at room temperature, which is 25°C or below, but it should always be kept in a sterile, covered container to make it as safe as possible for your baby to drink.

Formula is only suitable for digestion for the duration of a feed, which is usually one hour. This is because once saliva enters the bottle, germs can begin to form which could be harmful to your baby.

You shouldn’t leave your breast milk at room temperature for longer than 6 hours. If longer, you can only use it to treat skin flare-ups like eczema, nappy rash, and baby acne, or for sore nipples.

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Parents are busy, and no matter how organised you are, it’s totally normal to forget things from time to time. With that said, there’s no such thing as a stupid question like “is my breast milk still fresh?”, say if you’d forgotten you left it out while dealing with a nappy change. 

Fear not, we’ve written this guide for new parents to help you work out if your expressed breast milk is still safe to give to your baby. So, whether it’s been hand expressed or expressed using a pump, let’s run through how long breast milk can stay out of the fridge at room temperature.

How long can breast milk stay out of the fridge?

Freshly expressed breast milk can be stored for up to 6 hours at room temperature (25°C or below), but it should ideally always be stored in a sterile, covered container.

On the other hand, if the room is very warm, with a temperature of 29°C or higher, breast milk should only be left out for two hours.

It’s important to note that the longer breast milk is left out, the higher the risk of bacteria growth and contamination that can cause sickness and diarrhoea. So, it’s best to store your breast milk in the fridge or freezer as soon as possible if you’re not going to feed it to your baby right away.

How long can I leave breast milk out for a premature baby?

Premature babies should only be given breast milk within one hour of being expressed if it’s being kept at room temperature.

How do I know if my breast milk has gone off?

For signs of spoiled breast milk, all you need to do is give it a sniff test. If it smells sour or slightly off, it’s best to discard it to be on the safe side.

Does breast milk spoil faster in hot weather?

Yes, it’s very likely that breast milk will spoil faster in hot weather as bacteria grows quicker in hot temperatures.

How long can breast milk sit out in a thermos?

If your thermos is pre-heated, you can use the breast milk safely for up to 4 hours, and if it’s kept ice cold using ice packs around the thermos, it can last up to 24 hours.

 

 

What should I do if I’ve left breast milk at room temperature for over four hours?

Although a lot of effort goes into pumping and expressing breast milk, you shouldn’t feed your baby any that’s been left at room temperature for longer than 6 hours; this is breast milk’s shelf life at room temperature

But don’t worry, there’s no need to feel disheartened or waste the milk. You can use it to treat skin flare-ups like eczema, nappy rash, and baby acne. All you need to do is apply it directly to your baby’s skin or dilute it into their bath water.

Breast milk can even be used by parents to treat any rashes or eczema, and some women also use it to treat cracked and sore nipples caused by breastfeeding.

What are the risks of feeding a baby breast milk left out at room temperature?

The risks of feeding your baby breast milk that’s been left out for too long at room temperature include:

• Upset stomach
• Foodborne illness
• Reduced nutrient quality
• Weakened immune protection (from the milk’s antibodies)

These risks are even higher for premature babies because their immune systems are less developed.

Is it safe to leave breast milk out overnight?

No, this is unsafe as bacteria will likely multiple quickly within the milk, making it unsafe to digest.

How long does breast milk last in the fridge?

Once it’s been expressed, breast milk should ideally go straight into the fridge in a sterilised container, bottle, or milk storage bag if you’re not going to give it to your baby right away. And expressed breast milk can be stored in the back of the fridge (where it’s coldest) for up to 6 days.

It’s important to remember that breast milk shouldn’t be stored in the door of the fridge as the temperature fluctuates when the door is opened and closed.

If your fridge is warmer than 4°C, expressed milk should be used within three days. If your fridge doesn’t display a temperature, it may be handy to get a fridge thermometer to give you peace of mind.

 

 

How long can defrosted breast milk stay out?

Breast milk that was previously frozen and has been safely thawed can be kept at room temperature for up to 2 hours or stored in the fridge for up to 24 hours. Please remember, breast milk should not be re-frozen once it’s defrosted, and any milk that’s left over after two hours must be wasted or refrigerated and used only as a skin ailment treatment.

Breast milk storage guidelines

Your expressed breast milk can be stored using the following guidelines…

Please note that these guidelines are for healthy, full-term babies. You should speak to your doctor if you’re pumping milk and your baby has health complications or was born prematurely.