16. Hydrogen safety measures and their significance
The Paris Agreement on climate change and mitigation of greenhouse emissions has been ratified by all states worldwide with the exception of four states (Eritrea, Iran, Libya and Yemen) which have signed but not ratified the Agreement. The EU and all its member states are strongly committed to its implementation and in line with this commitment; the European Green Deal was approved in 2020 with the overarching aim of making Europe climate neutral by 2050. Similar long-term reduction plans to achieve net zero emissions by 2050 have been released by most countries outside EU, e.g. UK, Canada, Australia, Japan, South Korea, etc., while China aims to achieve net-zero emissions before 2060. The United States announced a commitment to reduce national greenhouse (GHG) emissions 50–52% by 2030 as part of the United States’ “nationally determined contribution,” or NDC and become carbon-neutral by 2050.
In this context, hydrogen can play a critical role to achieve the decarbonisation goals worldwide in several sectors, including hard-to-abate industries (steel and cement production) and heavy transport (truck, buses, trains, ships, and airplanes).
For hydrogen to take a prominent role in the energy sector, safe design of equipment and structures is required along with proper safety controls during their entire life cycle from design to decommissioning. Over-cautious regulatory restraints should be revised to ensure that they address tangible risks. Existing codes and standards for hydrogen equipment and processes can serve as guidelines for industry and governments. However, national regulations should be developed, or existing provisions amended to permit the safe use of hydrogen.
There is a range of practical safety measures which can be applied to hydrogen technologies, as set out in the individual sections covering each scenario. All installations require good standards of design and construction, combined with safe operational practices and maintenance. Fixed installations may also require safe separation distances from vulnerable populations and other high-risk installations.
If adequate safety measures are adopted for hydrogen technologies, the residual risks to safety associated with hydrogen is comparable to that associated with conventional fuels.
However, in many countries, there are no specific safety legislative frameworks for hydrogen technologies, although in many cases, existing safety legislation covering gas, energy, transport and heating sectors, can be applied to hydrogen. In some circumstances specific safety regulations on hydrogen might be required in where there are current safety gaps. Existing European and/or international safety regulations, such as the United Nations Global Technical Regulation No. 13 (GTR #13) (UNECE, 1998[1]) for hydrogen vehicle requirements can be used as a guide. Existing safety regulations might need revision to account for new technology advancements and innovations, while updated research findings could support less conservative measures to accelerate the deployment of hydrogen technologies and boost the hydrogen market.
In many places hydrogen deployment is very difficult if not impossible because of either complete ban or total uncertainty (there is no clear legal structure of responsible authorities and institutions)1 or overly conservative safety distances in fixed installations.
This report provides the basis for a risk-based regulatory framework to facilitate the further use of hydrogen as a source of energy. It summarises the key findings from a literature review and a review of international experience with hydrogen pilot projects and provides recommendations for the safer use of hydrogen in six scenarios covering the entire hydrogen value chain that new/revised regulations should focus on.
The OECD carried out a literature review on hydrogen hazards and risks, as well as a review of international experience with hydrogen pilot projects to consolidate existing knowledge. The review provides information on the extent of the consequences in the event of hydrogen fire and explosion, as well as providing insights on the probability of hydrogen ignition. The overall conclusion was that, due to the many factors that could affect the outcome, is not possible to calculate a consistent value of ignition probability. Moreover, risk calculations have a strong dependence on the assumed technical, location and operational conditions. In the absence of exiting safety legislation, it is recommended that application and technology targeted risk assessments are developed for specific scenarios/applications.
This report presents lessons learned and recommendations on key safety elements for hydrogen technologies that new/revised regulations could consider in order to achieve better outcomes.2 These recommendations are based on the OECD research findings3 with the aim to support regulatory and permitting authorities dealing with authorization requests for hydrogen applications, sites. The recommended safety measures should be considered as a list of options to reduce the risks related to hydrogen technologies. The extent to which all or some of the measures will be applied should be evaluated by the responsible actors taking into account also other aspects, such as financial, societal and environmental targets and risks.4 The recommendations are focused on six scenarios/applications that cover a wide spectrum of the hydrogen supply chain, including:
Road transport: a hydrogen transport truck driving in a built-up area experiences leakage;
Mobility and partially confined space: a hydrogen city bus driving in a tunnel is involved in a traffic accident;
Mobility and partially confined spaces: accident at a hydrogen fuel station, and
Domestic use: safety of hydrogen in buildings with a focus on hydrogen use in cooking stoves and boilers.
The findings are presented in separate sections for each scenario with a synthesis of the review of findings from research data and relevant safety recommendations for that scenario.
Reference
[1] UNECE (1998), Global Technical Regulations (GTRs): 1998 Agreement on Global Technical Regulations (GTRs), https://unece.org/transport/standards/transport/vehicle-regulations-wp29/global-technical-regulations-gtrs.
Notes
← 1. In this OECD report, see Part II: Regulatory review, provides a review on existing regulations for hydrogen applications across several countries.
← 2. In this OECD report, see Part II: Regulatory review, information about the ongoing regulatory developments in several countries can be found.
← 3. In this OECD report: See Part I: Report on literature review, Part V: Bow tie barrier analysis, Part III: Review of international experience with hydrogen pilot projects, Part II: Regulatory review.
← 4. Such analysis is beyond the scope of this report.