Hydrogen is a highly flammable gas, and can react violently with heat and flames, just as natural gas, gasoline fumes, and other volatile compounds that people use on a daily basis.
There is one particular incident in history that opened a misguided attitude toward hydrogen: the Hindenburg. On 1937 the Hindenburg airship was consumed by fire. The newspapers concluded, purely on assumptions that the disaster was caused by the ignition of the flammable hydrogen gas that made the airship buoyant. But after extensive research, it is now known that hydrogen was not to blame for the airship disaster. The skin of the Hindenburg was painted with an extremely flammable doping agent of cellulose acetate butyrate with powdered aluminum and iron oxide. This is virtually the same substance used to make solid rocket fuel. This led to a new theory that the Hindenburg disaster was started by an ignition of the airship’s covering material brought about by discharges of an electrostatic nature. Experts had expressed that this disaster would have happened even if helium had been used as the lifting agent instead of hydrogen.
Later, because of the cold war in the ‘50s hydrogen started being associated with the word “bomb". What is kept aside this association is that a hydrogen bomb cannot be made from ordinary hydrogen. It requires very special isotopes (atoms whose nuclei have the same number of protons but different number of neutrons), which are very hard to isolate in sufficient quantity in order to cause trouble. Indeed, it has never been done by anyone other than a handful of governments that fund multibillion-dollar weapons programs.
Hydrogen becomes explosive only when confined and mixed with air. The greatest disadvantage of hydrogen is that a pure hydrogen flame is invisible. You can walk into it before you knew there was a fire. It has been suggested that a chemical could be added to hydrogen to give it a visible flame, but for fuel cells that demand very high purity H2 that practice might not be convenient. Hydrogen has neither color, nor odor therefore in the case of a leak it can be difficult to identify; hydrogen detectors could be a solution to this kind of situation. Another matter of great concern is the extreme pressures under which it must be stored and transported, for which very tough and enduring tanks must be used.
Safe practices in the production, storage, distribution, and use of hydrogen are essential components of the hydrogen business. Like most fuels, hydrogen can be handled and used safely with appropriate sensing, handling and engineering measures. There are numerous codes for dealing with the use of hydrogen and other flammable gases in an industrial environment. These standards should be consulted to ensure that hydrogen installations are properly engineered. There is no reason to think we cannot become accustomed to use hydrogen in the same way we use gasoline and natural gas in our daily routines.