Heathrow Airport bosses have issued an alert to all passengers regarding the 100ml liquids rule for hand luggage. The rule came into force in 2006 as a “temporary measure” to protect against explosives.

It was due to be reversed by June of this year, with some smaller UK airports managing to install new CT X-ray scanners by this deadline. Other larger airports did not manage to, with reasons varying from supply chain problems to necessary construction work.

Heathrow, the UK’s largest and busiest airport, sees over a hundred thousand people pass through its four terminals each day on average. Due to its size and the volume of passengers, Heathrow was not planning on introducing the liquids rule change until 2025.

But in mid-June, the Department for Transport announced a U-turn, meaning all airports in the country who had dropped 100ml liquids rules must reintroduce them. There is not yet a date for when the rules will be relaxed again.

An X post from the official Heathrow Airport account on Tuesday reminds passengers of current hand luggage rules. It reads: “Good morning and welcome to Heathrow Airport. As always we’re on our keyboards ready to assist with any airport related queries. Remember, liquids should be under 100ml and in a clear bag when going through security.”

The alert is accompanied by a link to a page on the airport’s website, which further explains: “Only limited quantities of liquids may be carried through airport security into the departure lounge. This includes bottled drinks, suntan lotion, fragrances, cosmetics, toiletries and all frozen liquids.”

It adds that liquids, creams, gels, pastes and aerosols may only be carried in containers holding 100ml or less and must be carried separately in a clear and resealable bag that is no bigger than 20cm x 20cm. The bag must be able to close properly with all items inside, and should be placed in a tray at security control.