TUV Verband – New information sheet on metal damage caused by hydrogen
The new TÜV Association leaflet 1276 demonstrates how gaseous hydrogen affects metals and how damage to systems can be avoided. It offers experts practical assistance in selecting suitable materials and testing methods.
Berlin, October 20, 2025 – Hydrogen is considered the energy source of the future. The gas can be produced in a climate-neutral manner, used in a variety of ways, and stored for long periods. However, for hydrogen to be transported, stored, and used safely, the materials used must be particularly robust and carefully tested. “Hydrogen can change and weaken metals over time,” says Ingo Blohm, a consultant for quality requirements and steam boiler systems at the TÜV Association. “This can cause pipes and tanks to crack, leak, or, in the worst case, break.” A recent leaflet from the TÜV Association shows how this can be avoided. It describes how suitable materials can be selected and tested to ensure the safe operation of hydrogen plants.
Blohm, says:
The question of materials is crucial to the success of the hydrogen economy,
“Our goal is to translate technical knowledge into clear recommendations for safe plant operation.” In keeping with this, the topic of material and plant safety is moving into the focus of the hydrogen industry at the Hamburg trade fair “Hydrogen Technology Expo Europe” and is illuminating a field to which the TÜV Association is making an important contribution with its new information sheet.
When hydrogen changes the metal
Handling gaseous hydrogen puts materials to a severe test. When the gas penetrates a metal, its tiny atoms push themselves between the metal atoms. This changes the internal structure: the material becomes more brittle, loses strength, and can suddenly fail under stress.
Blohm, says:
Hydrogen-induced cracking is particularly common,
“Hydrogen penetrates the finest pores in the metal and weakens the bonds between the atoms.” Under stress, this can cause tiny cracks to develop that grow unnoticed over time and ultimately lead to the fracture of a component. Another form of damage is so-called blistering. Here, hydrogen gas collects in small cavities inside the material. The resulting pressure can cause the metal to bulge or even detach. Hydrogen can also be dangerous at weld seams. Under stress, cracks preferentially form there, an effect that experts refer to as stress corrosion cracking.
Blohm , says:
Such damage often develops gradually and remains undetected for a long time
“That’s precisely why it’s crucial to understand the mechanisms precisely and to select suitable materials that can withstand these stresses right from the planning stage.”
Materials testing and construction: How metal remains stable under hydrogen
In the view of the TÜV Association, preventing such damage requires technical knowledge, clear testing procedures, and practical guidelines. This is precisely where this leaflet comes in. It shows which testing methods are suitable for detecting hydrogen-related damage in a timely manner. These include ultrasonic testing, which can detect fine cracks or changes within the metal, as well as X-ray or pressure tests, which reveal weak points before they become safety-relevant.
The leaflet also contains tips on how components can be designed and manufactured to make them less susceptible to embrittlement or cracking. One focus is on welding technology.
Blohm, says:
When joining metal parts, high temperatures and stresses often arise, which can make the material more vulnerable,
Internal stresses can be reduced through specific welding processes, filler materials, and targeted heat treatment after welding. This keeps the metal stable.
The design of the components also plays an important role, says Blohm:
If components are designed to distribute forces evenly, weak points can be avoided from the outset.
“Smooth transitions instead of sharp edges, the right wall thickness, or a smooth surface can determine whether a component lasts for decades or develops premature cracks.”
Hydrogen brings new challenges for regulations
Although hydrogen applications in industry, energy supply, and mobility are increasing, there are currently no binding regulations governing how materials should be evaluated under the influence of hydrogen. Existing standards and technical regulations have so far only addressed the topic of hydrogen embrittlement in passing. With this new information sheet, the TÜV Association provides clear guidance to experts involved in the planning, testing, and operation of hydrogen systems and supplements existing regulations with practical recommendations.
Blohm, says:
Many existing regulations were developed for conventional gases and have so far only inadequately taken into account the special properties of hydrogen,
“With the increasing use of hydrogen, new technical requirements are emerging, to which standardization and practice are gradually adapting. Our fact sheet provides initial guidance and summarizes the current state of knowledge.”
New information sheet available online
The new TÜV Association leaflet 1276 “Damage to metallic materials due to the influence of gaseous hydrogen – Introduction for experts” is now available as a digital version in the TÜV Association’s online shop and costs €95.94: https://shop.tuev-verband.de/merkblaetter/MB-WERK-Werkstoffe/Schaedigung-metallischer-Werkstoffe-durch-den-Einfluss-von-gasfoermigem-Wasserstoff-Einfuehrung-fuer-Sachverstaendige-MB-WERK-1276?mtm_campaign=1276pm
From October 21 to 23, 2025, representatives of the international hydrogen industry will also meet at the Hydrogen Technology Expo Europe in Hamburg. The trade fair thus addresses a topic that is also central to the TÜV association: the safety of materials and systems used in hydrogen handling.
READ the latest news shaping the hydrogen market at Hydrogen Central
TUV Verband – New information sheet on metal damage caused by hydrogen, source
