Hydrogen occurs stably only as molecular hydrogen (H₂) and is a colourless and odourless gas. It reacts rapidly with oxygen (O₂) to form water, releasing energy. H₂ is not toxic but has flammable / explosive properties.
Most of the hydrogen found on Earth is bound in water. This means that it is present in the Earth's atmosphere (here as water vapour) as well as in oceans and waters and in all living organisms. Without hydrogen, no transport of substances through the body would be possible.
Hydrogen is currently important for industry primarily as a possible energy carrier for saving CO2. The hydrogen is produced by electricity from a (preferably renewable) primary energy source.
Hydrogen is harmless to the human body. Even outdoors, there is little danger, as it evaporates immediately after escaping from collection containers. In closed rooms, however, the gas collects under the ceiling because it is lighter than air. The gas is easily ignited when it escapes - the dissipation of electrostatic charge from clothing provides sufficient energy.
Escaping liquefied hydrogen can cause cold burns on contact. Transport containers and storage rooms in particular must therefore be well secured. Sufficient room ventilation is generally recommended.
As the gas has no direct effect on human health, no limit values have been set.
However, physical limits exist. The ignition range of hydrogen in air is between 4-76% by volume. Above 18%, the mixture is explosive (oxyhydrogen). The ignition temperature in air is 560 °C.
There is a risk of explosion in high concentrations. To avoid this, rooms in which hydrogen is stored should be well ventilated and equipped with a ceiling extractor.
Gaseous hydrogen is almost non-existent on Earth. It is predominantly present in bound form as water.
Hydrogen can be produced industrially by various methods (e.g. electrolysis).
Hydrogen is measured in the air-Q by means of an electrochemical sensor. H₂ molecules "dock" on the surface of the sensor and cause a measurable current. The sensor has a high accuracy. The disadvantage of all electrochemical sensors is cross-sensitivity. The only known cross-sensitivity of the H₂ sensor is carbon monoxide. If this gas is present, a small H₂ increase is also indicated.
Measure hydrogen and other gases and pollutants in indoor air in real time with the air-Q air analyser. The hydrogen sensor can be ordered in the shop.