Do Not Open Near A Jet Engine

In 2011 the whole world took notice when Eyjafjallajökull volcano erupted with catastrophic effect on air traffic and a nightmare for air traffic controllers around the world.
At the 2012 ATC Global in Amsterdam, a conference of air traffic controllers, ISAVIA decided to give out 2000 sample glasses with volcanic ash from the eruption. The humor was not lost on the guests and the samples became treasured memento.