Is hydrogen safe?

Hydrogen has been safely produced and used for over a century, and it is used in multiple industrial applications such as petroleum refining, fertilizer and chemicals production, metals manufacturing, and food processing. As with gasoline, diesel, natural gas, and other fuels, hydrogen must be handled appropriately, safely, and responsibly with a focus on potential impacts to communities, public health, and the environment. Systems in use today have been engineered to reduce risk and enable the safe handling and use of hydrogen. Hydrogen fuel cell vehicles and hydrogen fueling stations are required to meet rigorous safety standards similar to their gasoline and diesel counterparts. 

Hydrogen is non-toxic¹ and can diffuse or dissipate rapidly, rather than pooling. For example, hydrogen gas leaking from a tank would rapidly diffuse into the air, into concentrations low enough that it would no longer be flammable,² whereas liquid fuels like gasoline or diesel can accumulate on the ground into flammable or combustible pools. While hydrogen is colorless, odorless, and tasteless, it is highly flammable, similar to other fuels; and while hydrogen does not act as a direct greenhouse gas—trapping heat in the atmosphere—it can indirectly contribute to global warming through its effects on other climate gases, such as methane and ozone. Therefore, monitoring for emissions and avoiding leakage are high priorities.

Hydrogen pipelines and storage tanks are also designed, manufactured, and operated with care to mitigate risks such as embrittlement, which occurs when hydrogen is absorbed into metals over time, affecting the mechanical properties of the metals and making them more prone to cracking.^3,4 Specific materials, thicker walls, more frequent replacements, and more frequent inspections can help to manage embrittlement. Hydrogen tanks are typically subject to rigorous testing, including burst testing, drop testing, and even gunfire testing, before being placed in service.⁵

The U.S. Department of Energy is funding ongoing research into safe hydrogen handling and storage practices, hydrogen-compatible materials,⁶ and leak detection systems. See the Hydrogen and Fuel Cell Technologies Office's (HFTO's) Safe Use of Hydrogen webpage⁷ and the Safety, Codes and Standards webpage⁸ for more information about hydrogen safety. There is also significant ongoing research into hydrogen sensor development at the national labs,⁹ and HFTO's and ARPA-E's funding opportunity announcements have provided funding for hydrogen sensor research.^10,11 For examples of ongoing research on hydrogen sensors, see HFTO's 2024 Annual Merit Review Safety, Codes, and Standards presentations.¹²

Additional information about hydrogen safety can be found at H2Tools¹³ and the Hydrogen Safety Panel.¹⁴