Many major airports are in the process of phasing out the restrictive "100ml liquid rule" (3-1-1 rule), though the global rollout is inconsistent. This change is made possible by the introduction of advanced CT (Computed Tomography) scanners at security checkpoints. These scanners create a high-resolution 3D image of a bag's contents, allowing security officers to distinguish between harmless liquids (like water or shampoo) and potential explosives without the passenger needing to remove them from their luggage. In the United Kingdom, the government mandated that major airports install this technology by 2024–2025, and airports like London City and Teesside have already scrapped the 100ml limit entirely, allowing up to 2 liters. Similarly, some terminals in Spain, the Netherlands, and the United States (via TSA's new scanner rollout) are moving in this direction. However, until this technology is universal, travelers are advised to stick to the 100ml rule for international trips. If you fly from an "advanced" airport but have a connection at an older one, your larger liquids may still be confiscated at the second security check, making it a "halfway" convenience for now.