Starting September 1, airports across the European Union will reinstate stricter regulations for liquids in hand luggage, limiting passengers to containers no larger than 100 millilitres.

According to the German news agency dpa, passengers must also place these liquid containers in a single transparent plastic bag with a maximum capacity of 1 litre. These rules, originally implemented in 2006, had been relaxed at certain German airports where computer tomography (CT) scanners were used to inspect baggage. These scanners, which utilize medical imaging technology to create a three-dimensional view of the contents, allowed for more lenient liquid regulations.

However, EU officials have expressed concerns over the reliability of these new CT baggage scanners. The German Federal Police and Frankfurt Airport operator Fraport highlighted this impending rule change on Wednesday. The previous leniency, which allowed liquids to stay inside bags, is now discontinued, at least temporarily, as a security review of the new scanners is conducted.

Exceptions to the liquid rules include medication and liquid baby food. Under new EU regulations, liquid containers can remain inside baggage at checkpoints equipped with new scanners. Nonetheless, at checkpoints with conventional scanners, which are still prevalent in many EU airports including those in Germany, liquids and electronics must still be unpacked and presented separately.