From China Daily:
Passengers taking international flights from the Beijing Capital International Airport during the May Day holiday should arrive at the airport at least 2 hours before departure because of extended security checks.
A new rule starts today, limiting passengers to carrying no more than 1 liter of liquid in their hand luggage.
The liquid ban was first introduced on December 11, 2006, after British police foiled a terrorist plot to smuggle liquid explosives onto an aircraft that was scheduled to fly from Britain to the United States in August 2006.
Soon afterwards, the CAAC adopted the measures for passengers flying to the US and have been effective ever since. [Full Text]