A TikTok user's bold attempt to test Heathrow Airport's liquid restrictions has sparked debate among travellers, revealing a surprising outcome and highlighting the ongoing confusion around UK airport security rules.
The Social Media Experiment
On December 28, 2025, a traveller known online as Khoslaa documented her journey through Heathrow security on TikTok. Her mission was to see if the airport had followed others in the UK by relaxing the long-standing rule that limits liquids in hand luggage to containers of 100ml or less. Initially planning to carry a hefty 2-litre bottle, she later swapped it for a 125ml can of hairspray, citing the original bottle's weight.
Despite feeling "nervous" and noticing an unusually high security presence that day, Khoslaa proceeded. She even filmed parts of the process, overlooking a 'no camera' sign to record her bag's progress on the X-ray scanner. The footage captured the tense moment her luggage, containing the over-limit hairspray, passed through security screening.
The Unexpected Result and Passenger Confusion
Contrary to expectations, the influencer and her 125ml hairspray passed through Heathrow security without being stopped. This result left many viewers of her video puzzled, questioning whether it indicated a change in policy or was simply a security oversight.
The comments on the video reflected widespread uncertainty. One user directly asked about the rules in Terminal 4, while another correctly pointed out that although Heathrow's scanners sometimes allow liquids to stay in bags, the 100ml limit itself should still apply. A third commenter humourously warned about the potential difficulties of bringing the item back into the UK on the return journey.
Heathrow's Official Stance vs. Other UK Airports
At the time of the experiment, Heathrow Airport's official policy remained unchanged. The rules mandate that all liquids, gels, and aerosols must be in containers of 100ml (3.4oz) or less. These must be placed inside a single, transparent, resealable plastic bag, approximately 20cm by 20cm, which must be removed from hand luggage for separate X-ray screening.
This contrasts with several other UK airports, including London City, Teesside, and Newcastle, which have installed advanced CT scanners. This new technology allows passengers to carry up to two litres of liquids without removing them from their bags. Notably, the article confirms that as of late December 2025, only flights departing from Birmingham and Edinburgh airports within the Heathrow group permitted the increased liquid allowance.
The viral experiment underscores the patchwork of security regulations across UK airports, reminding travellers to always check the specific rules of their departure airport before packing their hand luggage to avoid last-minute stress or confiscations.
