The European Union has announced that 100ml liquid restrictions will be reintroduced at airports across the bloc from September. The update comes three months after the UK reintroduced the restriction across all airports, including those with Next Generation Security Checkpoints – designed to phase out the long-standing rule.

The European branch of Airports Council International (ACI) has warned that this “severe restriction” will cause “significant operational strain” by reducing the passenger throughput of security checkpoints. It is calling for 100ml liquids to be allowed to remain inside cabin bags when screened by next-generation CT scanners “in order to limit operational impacts.”

ACI also points to the fact that airports which have invested in the cutting-edge technology are being “penalised” by the restriction: “purchasing C3 scanners is on average eight times more expensive than the conventional X-ray screening machines they are replacing, while operating maintenance costs are four times higher.”

Several airports in Europe have upgraded security screening technology with Explosive Detection Systems for Cabin Baggage (EDSCB) scanners, which work in a similar way to hospital CT scanners to produce 3D images of luggage contents. They currently allow passengers to carry liquid containers exceeding 100ml – which can remain in hand luggage, along with electrical devices – and are in operation at busy hubs such as Amsterdam Schiphol and several airports in Ireland.

However, from 1 September 2024, individual liquid containers must revert to a maximum 100ml across all EU airports – including those using next-generation scanners – and must be removed from hand luggage for scanning. There is no time frame setting out when the rule will be relaxed.

The European Commission has said that the “precautionary measure is not in response to any new threat but addresses a temporary technical issue”, and that it is collaborating with member states and the European Civil Aviation Conference “to develop swift technical solutions”.

In the UK, the U-turn on restrictions was similarly blamed on technology. The Department for Transport stated that it was to allow for “improvements to be made to the new checkpoint systems”. It says that it is working with manufacturers, airports and international partners to lift restrictions when possible.

The change came in the same month as a DfT-mandated deadline for the installation of upgraded scanners at UK airports. Several major airports were granted a case-by-case extension to the June deadline until 2025 to allow for operational upgrades. The next-generation scanners are bigger and heavier than older versions and in some cases, security halls have had to be strengthened before introducing the new scanners.

At Birmingham Airport, work to security screening areas and passenger confusion was blamed for queues of up to three hours when the 100ml limit was reapplied, just as it was hoped to be lifted before the start of the busy summer holidays.

Olivier Jankovec, director-general for ACI Europe said that his organisation “regrets” the fact that no timeline and no process have been put in place to lift the 100ml restriction, calling on the European Commission and Member States “to urgently develop a road map with set milestones to waive the current restrictions and restore the trust in the EU certification system for aviation security equipment”.