In the UK, e-liquids and nic salts are allowed in hand luggage, but there are certain restrictions that travelers should be aware of. The UK government recommends that e-cigarettes and vaping devices should be carried in hand luggage rather than checked luggage, as they may pose a fire risk if they malfunction.
According to the UK government's guidelines, e-liquids and Nic salts should be placed in a clear, plastic bag with a maximum capacity of 1 litre and carried separately from other liquids in hand luggage. Each container of e-liquid or Nic salt must not exceed 100 millilitres in capacity, and the total amount of liquids carried in the plastic bag must not exceed 1 litre.