Hamley's, Smyths and Argos sell slimes containing chemicals up to four times higher than EU safety limit

We tested 13 toy slimes and putties from a range of high-street and online retailers including Amazon, eBay, Etsy, Argos and Hamleys.

More than 40% of the slimes and putties on sale for Christmas that we tested failed the EU safety standard for toys (EN 71-3). They're pictured above.

This is the second time in 2018 we've tested toy slimes and found alarming safety issues.

Last July, eight out of 11 toy slimes we tested exceeded the EU safety limit.

Go straight toBest Buy slimes.

The EU safety standard specifies that toy slimes must have boron levels that fall below 300mg/kg and toy putties must have boron levels that fall below 1,200mg/kg.

Exposure to excessive levels of boron could cause irritation, diarrhoea and vomiting in the short term, and may impair fertility and cause harm to unborn children in pregnant women.

The slimes that had levels of boron within the EU safety standard when we tested them are pictured directly below.

Which slimes had the highest levels of boron?

The worst slime we tested had four and a half times the permitted level of boron: 1,400mg/kg in one of the colours. This was Essenson DIY slime kit, below, which we bought from Amazon.

Goobands Frootiputti, which we bought from Hamley's, had 1,200mg/kg of boron in the sample we tested.

Our sample of HGL Ghostbusters slime, bought from Smyths Toys Superstores, had 950mg/kg in the sample we tested.

The sample of Zuru Oosh Fun Foam we tested, which was bought from Argos, had 1,700mg/kg of boron, but as it's classified as a putty, the permitted boron limit is higher.

Below you can see the full list of slimes we've just tested, and those that failed and passed our tests.

What to do if you've bought one of these slimes

We've passed our findings on to all the manufacturers with available contact details, and the retailers we bought the products from, asking for the slimes we tested that exceeded boron limits to be removed from sale.

If you've bought one of these slimes, our advice is to stop playing with it immediately.

You may be able to return the unsafe slime to the manufacturer for a refund or safe replacement using 14-day online or store returns policies.

If that's not an option you may be able to cite your Consumer Rights Act rights, on the basis that these products are unsafe and so of unsatisfactory quality and unfit for purpose.

Nikki Stopford, director of research and publishing at Which?, said: 'Slime will feature in many kids' letters to Santa this Christmas, however we've found more worrying evidence that children could be put at risk by these toys.

'Parents should have confidence that the products that they buy for their children will be safe, but our latest investigation has uncovered harmful products being sold even by big retailers.

'Again, we're calling on manufacturers to stop making unsafe products, and for the government and retailers to step up and do a much better job of ensuring only safe products get into people's homes and into the hands of children.'

What manufacturers and retailers told us

Both H Grossman Ltd, maker of the Ghostbusters slime andKeycraft Global (Goobands) makers of Frootiputti have disagreed with the Which? categorisation of their products as slime. Both argue that their products are putty and therefore pass the EU standard because putties are permitted to contain significantly higher levels of boron.

Which? stands by our accredited laboratory decision to classify Ghostbusters Slime and Frootiputti as slimes, rather than putties. This is based on the slime and putty definitions within the EU standard, and means that the levels of boron within both products could make them potentially unsafe.

H Grossman Ltd said: 'Consumers can see the reports from several independent accredited laboratories which confirm that this product is technically a 'putty' and that the levels of all elements are well within safety standards.

H Grossman Ltd commissioned two laboratories to analyse the batch mentioned by Which? These were sent to the magazine and also to Trading standards. The reports are also available to any interested person on request to H Grossman Ltd. H Grossman supplied these full reports to Which? before publication.'

Smyths Toys, stockists of this slime, told us: 'Children's safety is our first priority. Ghostbusters Slime was supplied to us by the UK distributor H Grossman who have provided us with test results which indicate that the product is within safety limits. We understand that they have also provided you with these results from an accredited independent laboratory.

'Like yourselves, we want to ensure that consumers are fully informed and that the highest safety standards are followed. The only solid information we have at this point is that provided from a reputable laboratory which indicates that such standards are being met.'

Keycraft Global (Goobands) makers of Frootiputti said: 'This product has been tested at two separate independent globally accredited testing houses and deemed to be a 'putty' not a slime, and therefore compliant with the relevant standards.'

Hamley's, stockist of Goobands Frootiputti, told us: 'Ensuring the safety and trust of our customers is one of our core values as a business, and we will never compromise on the safety of our products. We work closely with our suppliers and manufacturers to ensure all products meet the legal standards for toy safety.

'As a precautionary measure we have made the decision to remove all Goobands Frootiputti from our stores while we investigate this matter further.'

Jexybox, makers of Pink Glossy Slime (above), has taken all stock off eBay and is letting customers know that they should stop using it.

eBay, where we bought this slime, said: 'The safety of our customers is our number-one priority and our listings policy is designed to protect customers first and foremost. We work with regulators to ensure that all listings comply with the law and there are blocks in place to prevent the listing of illegal items. We constantly monitor our marketplace to enforce this.'

We have not received a response from Zuru, the makers of Fun Foam putty.

Argos, stockist of Zuru foam putty, told us: 'The safety of the products we sell is extremely important to us. We haven't received any complaints but we're in close contact with our supplier, Zuru, while they investigate.'

There were two slimes that failed our tests that we bought from Amazon; ME Life TikTock Fluffy pink slime and Essenson DIY Slime Kit.

Amazon told us: 'Marketplace sellers must follow our selling guidelines and those who don't will be subject to action, including potential removal of their account. The products in question are no longer available.