Cabin vs checked bag
Officers have discretion. A jumbo tub of slime — even sealed — will be refused at most cabin checkpoints, even when the rest of your liquids bag is fine.
| Where it's going | What's usually OK | Watch out for |
|---|---|---|
| Cabin bag | Pots of 100ml or less, inside the 1L clear liquids bag | Homemade slime in unmarked jars may attract extra checks |
| Checked bag | Larger tubs, sealed inside a plastic bag | Pressure changes can cause overfilled containers to leak |
Why slime counts as a liquid
It's pourable and conforms to its container — the two main tests security applies under the 100ml rule. 'Fluffy' or 'cloud' slime fails both. Play-Doh and kinetic sand are usually treated as solids and travel more easily, but officers still have the final call.
UK-specific note
In the UK, airport security generally applies the 100ml liquids rule to gels and paste-like items. Slime is likely to be treated the same way, even though it's a toy.
Parents: what to do before airport security
- Use small, labelled containers — clear shop pots beat mystery jars.
- Keep slime out of unmarked jam jars or food tubs that look suspicious on X-ray.
- Avoid glitter-heavy, metallic-looking, or very sticky homemade slime if you can — these get extra attention.
- Pack backup entertainment in case security removes it. Kids who lose their slime at the checkpoint don't recover quickly.
- For expensive or sentimental slime, put it in checked luggage rather than risking it in the cabin.
Packing tips
- Buy a small 50–80ml pot specifically for the flight.
- Pack jumbo slime tubs in checked luggage, double-bagged.
- Bring tablets, games, or stickers as a backup — slime can ooze and lose pressure at altitude.