Toy Slime

(Date: August 2018. Version: 1)

This factsheet has been written for members of the public by the UK Teratology Information Service (UKTIS). UKTIS is a not-for-profit organisation funded by the UK Health Security Agency (UKHSA) on behalf of UK Health Departments. UKTIS has been providing scientific information to health care providers since 1983 on the effects that medicines, recreational drugs and chemicals may have on the developing baby during pregnancy.

What is it?

Toy ‘slime’ is generally bright in colour and sold in a plastic pot. In July 2018 the UK consumer group ‘Which?’ found that eight out of 11 slime toys tested contained higher levels of a chemical called boron than is allowed in the EU. The boron found in slime toys comes from a substance called borax, which is added to toy slime to maintain its texture. Borax is also commonly found in detergents, enamel glazes, insecticides, and is used as a preservative in some contact lens solutions.

The information in this document is written for pregnant women who have handled or swallowed the brands of toy slime for which safety concerns have been raised. Details of these specific slime toys  can be found on the ‘Which?’ website (clicking here should take you directly to the report).

Will contact with toy slime in pregnancy harm my baby?

In general, products which are not made by an approved manufacturer should be avoided as they may not have gone through the recommended safety and quality control checks and could therefore contain harmful substances. Particular care should be taken with products sold via the internet or from market stalls.

Handling toy slime: Borax in toy slime cannot easily pass through unbroken skin. The amount entering the mother’s bloodstream and potentially reaching a baby in the womb is therefore expected to be very low and unlikely to cause problems. Although women are advised, as a precaution, to avoid handling slime with high levels of boron if pregnant, no treatment or testing is needed if handling has already occurred. 

Swallowing toy slime: Swallowing toy slime may result in borax poisoning (toxicity), depending on how much is swallowed. Symptoms of borax toxicity include diarrhoea, vomiting, kidney problems, skin inflammation and blistering, coma and convulsions (fits). If you experience any of these symptoms after swallowing toy slime, seek medical help immediately as early treatment can limit or prevent serious problems associated with borax poisoning.

One small study in humans showed that women who were exposed to boron in drinking water did not have a higher chance of having a miscarriage, stillbirth, early delivery, a baby with a birth defect, or a low birth weight baby compared to unexposed women. However, animal studies have not been able to rule out that ingestion of a chemical similar to borax may be linked to birth defects in the baby.

Will my baby need extra monitoring during pregnancy?

As part of their routine antenatal care most women will be offered a scan at around 20 weeks of pregnancy to look for birth defects and to check the baby’s growth.

Handling toy slime during pregnancy is unlikely to cause any problems that would require extra monitoring of your baby. There is, however, not very much information on boron poisoning in pregnancy. If you swallowed toy slime early in pregnancy while the baby was still developing your doctor may offer you a more detailed scan.

If you have swallowed toy slime and experienced symptoms of toxicity (see above), additional monitoring to ensure that the baby is growing and developing as expected may be recommended.

Are there any risks to my baby if the father has used toy slime?

We would not expect any increased risk to your baby if the father had contact with toy slime before or around the time you became pregnant.

Who can I talk to if I have questions?

If you have any questions regarding the information in this leaflet please discuss them with your healthcare provider. They can access more detailed medical and scientific information from

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General information 

Up to 1 out of every 5 pregnancies ends in a miscarriage, and 1 in 40 babies are born with a birth defect. These are referred to as the background population risks.  They describe the chance of these events happening for any pregnancy before taking factors such as the mother’s health during pregnancy, her lifestyle, medicines she takes and the genetic make up of her and the baby’s father into account.

Medicines use in pregnancy

Most medicines used by the mother will cross the placenta and reach the baby. Sometimes this may have beneficial effects for the baby.  There are, however, some medicines that can harm a baby’s normal development.  How a medicine affects a baby may depend on the stage of pregnancy when the medicine is taken. If you are on regular medication you should discuss these effects with your doctor/health care team before becoming pregnant.

If a new medicine is suggested for you during pregnancy, please ensure the doctor or health care professional treating you is aware of your pregnancy.

When deciding whether or not to use a medicine in pregnancy you need to weigh up how the medicine might improve your and/or your unborn baby’s health against any possible problems that the drug may cause. Our bumps leaflets are written to provide you with a summary of what is known about use of a specific medicine in pregnancy so that you can decide together with your health care provider what is best for you and your baby.   

Every pregnancy is unique. The decision to start, stop, continue or change a prescribed medicine before or during pregnancy should be made in consultation with your health care provider. It is very helpful if you can record all your medication taken in pregnancy in your hand held maternity records.

Disclaimer: This information is not intended to replace the individual care and advice of your health care provider. New information is continually becoming available. Whilst every effort will be made to ensure that this information is accurate and up to date at the time of publication, we cannot cover every eventuality and the information providers cannot be held responsible for any adverse outcomes following decisions made on the basis of this information. We strongly advise that printouts should NOT be kept for any length of time, or for “future reference” as they can rapidly become out of date.

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