TravelTravel NewsEdinburgh AirportNeed to knowSome UK airports are relaxing the rules, with this one being the exception for all passengers15:36, 20 May 2026This could lead to delays at the security checkpoint(Image: Getty)Airport security rules: How water bottles and playing cards could cause delaysHolidaymakers jetting off this summer need to be aware of some basic airport security rules that could catch them out at the scanners. Despite many UK airports scrapping the 100ml liquid rule thanks to cutting-edge scanners, there's one crucial exception that could trip up travellersMetal water bottles are allowed through, but must still be emptied before security. The new scanners can't penetrate the double-layer insulation on stainless steel bottles and thermos flasks, meaning they need to go through empty for safety reasons.The good news is that most airports offer free water refill stations after security. This way, travellers can top up their empty bottles after going through the scanners.Major airports, including Heathrow, Gatwick, and Birmingham, have all introduced the relaxed liquid rules as of May 2026. Edinburgh Airport warned passengers: "If you are carrying metallic or double-walled containers (including vacuum flasks, thermos flasks and metallic water bottles), please ensure the container is empty prior to the security checkpoint."It's not just water bottles causing delays at security - playing cards are also flagging up problems at security checkpoints. The innocent-looking deck can trigger additional screening because its stacked shape and density can give the impression that something's hidden inside.TSA expert Ian Cava advised airline passengers to remove cards from hand luggage and place them in the tray separately. "This helps speed up the process and reduces the likelihood of delays," he said.READ THE FULL STORY: Anyone who owns a stainless steel water bottle reminded of airport rule‌