To prepare for the demonstration, the demonstrator had transported 15 balloons (pre-filled with a hydrogen-oxygen gas mixture) in a large, black polyethylene garbage bag. During the demonstration set-up he opened the bag to remove a single balloon for stringing and floating. Without warning the entire bag of balloons detonated violently. Fortunately, the incident occurred an hour prior to the program and no one else was near. It was also fortunate that only a small box caught fire and that none of the other chemicals, already in place for other demonstrations, became involved.

The demonstrator suggests that the slow leakage of hydrogen from the balloons (no balloon type is capable of completely containing hydrogen gas) allowed for the accumulation of hydrogen and oxygen in the bag's headspace. The dry, sealed bag created an environment ripe for the generation of static electricity. Simply touching the balloons ignited the headspace, and, thus, all fifteen balloons.

It is clear that the safe storage and transportation of balloons filled with a hydrogen-oxygen gas mixture is in doubt. There remain few scenarios that do not involve enclosed spaces (a car, even an approved courier who may be transporting additional dangerous materials) and the potential for static discharge. Maybe a mesh bag could be used as long as sufficient ventilation is ensured. Nonetheless, using lecture bottles and filling balloons on-site seems to be the safest method.

The demonstrator feels fortunate that his injuries were relatively minor (no respiratory damage occurred) and urges that a full risk assessment be performed prior to the set-up, handling (balloon storage and transportation), and performance of this popular demonstration.