Slime Safety — A Guide for Parents

Slime is brilliant fun. It's creative, tactile, satisfying, and genuinely educational (there's real chemistry happening in that mixing bowl). But like any craft activity, it needs a bit of adult awareness to keep things safe.

This guide covers everything parents need to know: which ingredients to avoid, how to choose safe products, what UK safety standards mean, and how to handle the most common slime-making mishaps.

The short version: slime-making is safe when you use the right ingredients, supervise age-appropriately, and follow basic hygiene. This page gives you the confidence to say yes when your child asks to make slime — and the knowledge to keep it safe.

The Borax Question

Borax (sodium borate) is the most commonly cited slime "activator" in online recipes. It works well, but we don't recommend using borax powder for children's slime-making in the UK.

Why Not?

Borax powder can cause skin irritation, especially with prolonged or repeated contact
If accidentally ingested, it can cause nausea and stomach upset
The concentration in DIY recipes is hard to control precisely
The UK's Health and Safety Executive classifies borax as a substance that may damage fertility — while the amounts in slime are tiny, safer alternatives exist

What to Use Instead

Contact lens solution containing boric acid (e.g., Boots own-brand multi-purpose solution, around £4) + bicarbonate of soda — this is the activator combination used in all our slime recipes. The boric acid concentration is very low and designed for use with eyes, making it much safer for skin contact.
Liquid starch — available from some UK craft suppliers. Works as a direct activator with PVA glue.
Ready-made slime activator — products like Elmer's Magical Liquid (around £5) are pre-measured and designed specifically for safe slime-making.

Age Recommendations

Age	Guidance
Under 3	Not recommended. Slime ingredients and small additions (glitter, beads) are a choking hazard.
3–5	Pre-made slime only (bought, not homemade). Adult must supervise at all times. No small additions like beads or sequins.
5–8	Can participate in slime-making with direct adult supervision. An adult should handle the activator (contact lens solution).
8–12	Can make slime with adult nearby. Should be taught to follow recipes, measure ingredients, and wash hands after.
12+	Can make slime independently with basic safety knowledge. Adult should be available for questions or if using advanced ingredients (iron oxide, resin).

Allergy and Sensitivity Considerations

Skin Sensitivities

Some children may react to PVA glue, food colouring, or contact lens solution. Do a patch test first — apply a small amount to the inside of the wrist and wait 15 minutes.
If redness, itching, or irritation occurs, wash the area with soap and water and discontinue that ingredient.
Children with eczema or sensitive skin should wear thin disposable gloves when handling slime.

Latex Allergies

Some slime products and toys contain natural rubber latex. Check packaging if your child has a latex allergy.
Our homemade slime recipes are latex-free.

Gluten Sensitivities

Some play dough products contain wheat flour. Check ingredient lists if your child has coeliac disease or wheat sensitivity.
PVA-based slime is gluten-free.

UK Product Safety Standards

When buying slime, sensory toys, or craft kits, look for these marks:

UKCA Mark

The UK Conformity Assessed mark replaced the CE mark for products sold in Great Britain from 1 January 2025. It means the product has been tested against UK safety regulations including:

BS EN 71-1 — Mechanical and physical properties (choking hazards, sharp edges)
BS EN 71-2 — Flammability
BS EN 71-3 — Migration of certain elements (toxic substances)

What to Check on Packaging

UKCA mark clearly displayed
Age recommendation printed
Manufacturer name and UK/EU address
Batch or serial number
Warning symbols where applicable (e.g., "Not suitable for children under 36 months")

Red Flags

No safety marking at all
No manufacturer information
Extremely cheap products from unknown sellers on online marketplaces
Strong chemical smell when opened
Packaging only in a language you can't read

Slime Hygiene

Always wash hands before and after making or playing with slime
Don't eat slime — it's non-toxic but not food. Keep it away from mouths.
Don't put slime near eyes — if contact lens solution or activator gets in eyes, rinse with clean water for 10 minutes
Throw away slime that's gone mouldy, smells odd, or has been contaminated
Store slime in sealed containers — this extends its life and prevents it drying out or picking up bacteria
Clean surfaces after slime-making. Warm soapy water handles most residue. Vinegar helps with stubborn spots.

Common Slime Mishaps (and How to Handle Them)

"It's stuck in their hair!"

Don't panic. Work conditioner or coconut oil through the affected hair. The slime will break down and slide out. Wash with shampoo after.

"It's on the carpet!"

Let it dry completely, then pick off as much as possible. Apply white vinegar to the remaining residue, let it sit for 5 minutes, then blot with a damp cloth. Repeat if needed.

"It's on their clothes!"

Scrape off the excess. Soak the garment in white vinegar for 30 minutes, then wash as normal. Works for most fabrics.

"They've eaten a tiny bit!"

The ingredients in our recipes (PVA glue, contact lens solution, bicarbonate of soda, food colouring) are non-toxic in small amounts. If a child eats a very small amount inadvertently, there's no cause for alarm. If a larger quantity is consumed or the child feels unwell, contact NHS 111 or your GP.

"Their skin is irritated!"

Wash the area with soap and water. If irritation persists, apply a simple moisturiser. If it's severe or doesn't improve, consult your GP. Next time, use gloves or try a different slime recipe.

The Bottom Line

Slime-making is a safe, creative, educational activity when done with the right ingredients and appropriate supervision. Use our recipes (which avoid borax powder), supervise according to your child's age, choose safety-marked products from reputable retailers, and keep things clean.

Then let them get gloriously, brilliantly messy.

Slime Safety — keeping craft time safe and fun. Adult supervision recommended for all ages. Part of GOO.

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