Ghie, are you referring to the general ban on liquids and gels being taken into the secure area of airports?
Since the foiling of a plan to bring down UK-US aircraft through the mixing of certain chemicals to produce explosives onboard flights... authorities have banned all liquids and gels in hand baggage of more than 100ml in size.
The full rules are here http://www.airsafe.com/danger.htm
Although there is talk of special explosives sniffer machines being introduced which would do away with the need for this ban. about 7 years ago