Liquids including gels, beverages, toothpaste and lotions carried by passengers must be stored in containers no larger than 100 ml. All containers must fit in a one-litre transparent and re-sealable plastic bag.
Baby food and essential medicines used during the flight are exempt from the regulations. Liquids bought in the tax-free airport shops after security checkpoints may also be taken into the cabin.
The Helsinki-Vantaa airport has increased staff levels to prepare for the new regulations. Passengers are being urged remember the new rules while packing and to arrive early.
For those who need to repack, zip-lock bags are being made available in the depature halls.
Passengers now also have to take off all coats and jackets at security checks and remove laptop computers and other large electrical items from their bags for inspection.
The new regulations are in effect throughout the EU, and in Norway, Iceland and Switzerland. The restrictions were put into place following a foiled plot last summer to blow up U.S. bound airliners leaving Britain.
YLE TV News, Reuters Finnish Civil Aviation Authority