Quick answer
Branded slime like Gui Gui (ages 6+) is tested against UK toy rules. The problem is cheap kits: 11 of the 14 UK slime safety alerts were for too much boron, the chemical that makes it stretchy. Buy a brand you know, check for a UKCA or CE mark, and wash hands after.
What's the slime craze this time?
Slime never really leaves, it just comes back with a new brand. Right now it's Gui Gui, made by Moose Toys with the YouTuber Salish Matter. Each pack comes with slime in four textures (gloss, clear, butter and cloud), scents, a little figure and decorations to mix in. Gui Gui is on Smyths' top toys list for Christmas 2026 and was on the industry's DreamToys list last year. It's marked for ages 6 and up.
Is slime safe?
Slime from big toy brands is tested against UK toy rules. The trouble is cheap slime and slime kits. The UK has issued 14 safety alerts on slime, and 11 were for too much boron, the chemical that makes slime stretchy. The legal limit for slime is 300 mg/kg, and failed samples have tested at up to 931. The official alerts say too much boron may harm children's health by damaging the reproductive system. The rest were for phthalates, chemicals used to soften plastic.
Wash hands after playing, keep it away from toddlers who'll put it in their mouths, and bin any slime that smells strongly of chemicals.
How do I avoid dodgy slime?
- Buy a brand you recognise from a shop you know. Five of the slime alerts were for products sold through Amazon's marketplace.
- Check the packaging for a UKCA or CE mark, a UK address, and an age rating. No mark is a red flag, but fakes can carry one too.
- Be wary of cheap multi-packs and kits. Several of the failed products were slime kits, including one pack of 20.
- Search our slime recall tracker by name or barcode.
How much does slime cost?
A single Gui Gui pack costs around £12 (one UK retailer we checked listed it at £11.77). Bigger "haul" and deluxe sets cost more. Cheaper no-name slime is easy to find, but that's where the safety problems turn up.
Is it just a phase?
Slime itself is basically permanent. It returns every couple of years with a new name on the tub. Gui Gui is the current name, and it'll be in a lot of stockings this Christmas.
Already got slime at home? Check it against every UK slime alert.
