Balloon races and releases
For special occasions or for the launch of a new product a massive balloon release can be an impressive sight.
A minimum of 1,000 helium-filled balloons go soaring up into the sky and are out of sight in only a few minutes. Often as many as 100,000 balloons are used and several million have been released on some occasions. If the balloons are tagged with race cards the finders of the deflated balloons can post the card back and the owner of the furthest-travelling card wins a prize.
Environmental protestors have claimed that the deflated balloons are a threat to wildlife and the notion of wasting all that effort and gas offends many people with "green" sensibilities.
It is very important to use only rubber balloons, not Mylar, because these will degrade rapidly in the environment. Self-sealing plastic valves must not be used in the balloons because these definitely mess up the environment in the short term even if the makers claim that they are "bio-degradable". The latex balloons should be hand-knotted to avoid the use of valves.