Airport Liquid Rules: What To Know Before You Go

Airport security has strict rules about the amount of liquid you can take on a plane, with containers holding liquids only allowed to be a maximum of 100ml. This is a security measure to prevent dangerous chemicals or explosives from being smuggled onto the plane. However, exceptions are made for urgent medicines or baby food. While there are liquid scanners at airports, they are not always used due to the time it would take to scan every liquid. Instead, security officers may use other methods such as placing the liquid in a machine or pouring a sample into a disposable cup to be scanned.

Liquids in hand luggage will be X-rayed

The X-ray screening process is mandatory in some countries, and failure to declare liquids may result in extra security checks and delays. It is important to follow the guidelines provided by the airport and the country's regulations to ensure a smooth security process.

Some airports have implemented advanced liquid scanners, such as the INSIGHT100 Raman spectrometer, which can detect potential explosives in liquid containers. These scanners are highly reliable and have a low false alarm rate. However, they are typically used for exceptional cases, such as when passengers need to carry urgent medications or baby food exceeding the standard liquid limit.

It is important to note that the restrictions on liquid quantities are in place for security reasons, and even with advanced scanners, these restrictions may still apply to ensure the safety of passengers and the aircraft.

Some airports have liquid scanners

Some airports have introduced new liquid scanners, which use CT X-ray technology to provide 3D images of luggage. This means that security officers can identify liquids without needing to remove them from bags. These scanners also allow passengers to carry containers of liquid larger than 100ml, and to leave laptops in their bags.

However, these scanners are not yet in operation in all airports. Airports such as Teesside and London City have finished installing the new equipment, but larger airports like Heathrow, Gatwick, and Manchester are still in the process of implementing the new technology. This is due to factors such as the high cost of the scanners, the need to reinforce terminal floors to support the heavy machines, supply chain issues, and the time required to train staff.

The introduction of liquid scanners is expected to improve security and make air travel more convenient for passengers. However, it is important to note that these scanners cannot determine the specific substances present in a liquid. Proper analytical equipment, such as spectrophotometers and chromatographs, are required for that level of analysis.

Scanners can't tell the difference between liquids

Scanners cannot tell the difference between liquids. It is impossible to determine the substances present in a liquid without proper analytical equipment. For example, a spectrophotometer or a chromatograph would be needed to determine the contents of a liquid.

Some airports have special liquid scanners that can tell in seconds if a liquid poses a threat. These machines are about the size of a microwave and can accommodate large or oddly-shaped containers. If a container doesn't fit, a small sample of the liquid can be poured into a disposable cup that is placed in a special holder on the side of the machine. The machine will then scan the liquid and display "OK" or "not OK" on a screen.

However, these machines are not in widespread use due to the time it would take to scan every liquid that passengers want to bring on board. This would create long security lines and cause disruptions to airport operations.

Special scanners can check for explosives

One such machine is the INSIGHT100 Raman spectrometer, which has been used as a liquid explosive detection system (LEDS) at many airports around the world. Its successor, the INSIGHT200M, can also check liquids in metal containers and is more efficient because it doesn't require different technologies to scan different types of containers. This machine is also smaller, which is advantageous given the limited space in passenger screening areas.

Another example of a liquid scanner is the SEEKERe automated colorimeter, which is a low-cost solution that is ideal for smaller airports. Both the INSIGHT200M and the SEEKERe are approved as LEDS and comply with Standard 2 Type A.

In addition to these scanners, the Transportation Security Administration (TSA) uses explosives trace detection technology, where officers swab a passenger's hands or a piece of baggage and then place the swab inside a detection unit to analyze it for potential explosive residue.

Some liquids are allowed on planes

Liquids, gels, and aerosols are permitted on planes, but only under very specific conditions. The current rules state that liquids must be in 100ml / 100g containers and that each container must fit inside a single, clear, resealable plastic bag no larger than one litre in volume. The bag must be removed from your carry-on luggage and scanned separately at the security checkpoint.

There are some exemptions to the 100ml rule, including breast milk, baby food, essential medical liquids, and dietary requirements. These vary by country, so it's important to check the relevant regulations for your departure airport.

Liquids bought after the security checkpoint, including duty-free, are also allowed on planes if they are sealed inside a tamper-evident bag with a receipt.

The restrictions on liquids were introduced in 2006 after a terrorist plot was foiled in which liquid explosives were to be used to down multiple transatlantic flights. The rule was initially intended as a temporary measure but has been extended indefinitely due to ongoing security concerns.

However, change is on the horizon. High-tech computed tomography (CT) scanners are being introduced at airport security checkpoints, enabling security staff to see the contents of carry-on baggage more clearly. These machines produce detailed 3D images that can be rotated and inspected from multiple angles, providing more reliable information to security officers.

CT scanners have already been installed at airports in London, Milan, Shannon, Donegal, Dublin, Teesside, London City, Los Angeles, New York, Austin, Providence, Rome, Munich, Nuremberg, and Prague, with more locations set to follow.

At airports with CT scanners, passengers may be allowed to carry larger volumes of liquids as long as they fit inside their cabin bags. However, it's important to note that regulations vary by country and airport, and the 100ml rule is still widely enforced. Until the new technology is more widely adopted and regulations are updated, passengers must continue to follow the existing liquid restrictions when travelling.

Frequently asked questions