Building Code Glossary
Metal Hydride Storage System: Building Code Definition
How the IFC 2009 define metal hydride storage system, where the wording differs, and which chapters depend on the term.
On this page
Last updated September 7, 2026 · Definitions quoted from the 2009 International Codes as transcribed in this site's building-codes collection, with the source chapter linked for each quotation. Usage counts are computed over the chapters hosted here, one copy per code. The [ICC code library](https://codes.iccsafe.org/codes) publishes the current model text and the [ICC adoption maps](https://www.iccsafe.org/advocacy/code-adoption-maps/) show which edition a jurisdiction has adopted; those sources control.
Direct answer
Metal hydride storage system is a defined term in the International Fire Code (IFC) 2009, in Flammable Gases and Flammable Cryogenic Fluids. The code's own words are: “A closedsystem consisting of a group of components assembled as a package to contain metal-hydrogen compounds for which there exists an equilibrium condition where the hydrogen-absorbing metal alloy(s), hydrogen gas and the metal-hydrogen compound(s) coexist and where only hydrogen gas is released from the system in normal use.” No other I-Code in this corpus defines it, so the IFC 2009 definition is the one to work from. The term is used in 2 chapters of this corpus, most often in Flammable Gases and Flammable Cryogenic Fluids (IFC 2009), Definitions (IFC 2009). These pages transcribe the 2009 model text; verify the definition against the edition and amendments your authority having jurisdiction has adopted.
Content and cited inputs reviewed by Scott Barrington, Harth founder and architectural technology specialist · Published 2026-09-07 · Updated 2026-09-07.
What does this term mean?
Metal Hydride Storage System — IFC 2009, Flammable Gases and Flammable Cryogenic Fluids:
A closedsystem consisting of a group of components assembled as a package to contain metal-hydrogen compounds for which there exists an equilibrium condition where the hydrogen-absorbing metal alloy(s), hydrogen gas and the metal-hydrogen compound(s) coexist and where only hydrogen gas is released from the system in normal use.
What must be verified before using this guidance?
Metal Hydride Storage System is defined once in this corpus, in the Flammable Gases and Flammable Cryogenic Fluids chapter of the International Fire Code (IFC) 2009:
A closedsystem consisting of a group of components assembled as a package to contain metal-hydrogen compounds for which there exists an equilibrium condition where the hydrogen-absorbing metal alloy(s), hydrogen gas and the metal-hydrogen compound(s) coexist and where only hydrogen gas is released from the system in normal use.
Where metal hydride storage system is used in the code
The term appears in 2 chapters of the 2009 I-Codes hosted here. The chapters that lean on it hardest are the ones to read next.
| Chapter | Code | Mentions |
|---|---|---|
| Flammable Gases and Flammable Cryogenic Fluids | IFC 2009 | 44 |
| Definitions | IFC 2009 | 1 |
The term in use
How the code actually writes about metal hydride storage system, quoted from the 2009 text hosted here:
The hazard classification of the metal hydride storage system, as required by Section 2701.2.2, shall be based on the hydrogen stored without regard to the metal hydride content.
The terms metal hydride storage system is built out of
The definition above leans on 1 other defined term. Each carries its own code definition, and a local amendment to any of them changes what metal hydride storage system covers:
- System — IFC 2009: An assembly of equipment consisting of a tank, container or containers, appurtenances, pumps, compressors and connecting piping.
Metal Hydride Storage System: what to open, and in what order
Every row is a document this term depends on. The ICC code library and the ICC adoption maps cover the middle rows.
| Check | Where | Confirmed |
|---|---|---|
| Read the definition in the adopted IFC | Flammable Gases and Flammable Cryogenic Fluids | |
| Re-check the requirement that uses it | Flammable Gases and Flammable Cryogenic Fluids (IFC 2009) | |
| Re-check the requirement that uses it | Definitions (IFC 2009) | |
| Confirm the dependent definition | System | |
| Local amendment to any of the above | Jurisdiction's amendment list |
A research aid, not a code determination. The authority having jurisdiction decides which edition and which amendments apply.
Where can you explore related guidance?
- Explore all glossary guidance
- System: Building Code Definition
- Bulk Hydrogen Compressed Gas System: Building Code Definition
- Bulk Liquefied Hydrogen Gas System: Building Code Definition
- Hood: Building Code Definition
Sources and method
Definitions quoted from the 2009 International Codes as transcribed in this site's building-codes collection, with the source chapter linked for each quotation. Usage counts are computed over the chapters hosted here, one copy per code. The ICC code library publishes the current model text and the ICC adoption maps show which edition a jurisdiction has adopted; those sources control.
Source links
Frequently asked questions
What is the code definition of metal hydride storage system?
The International Fire Code (IFC) 2009 defines it in Flammable Gases and Flammable Cryogenic Fluids as: “A closedsystem consisting of a group of components assembled as a package to contain metal-hydrogen compounds for which there exists an equilibrium condition where the hydrogen-absorbing metal alloy(s), hydrogen gas and the metal-hydrogen compound(s) coexist and where only hydrogen gas is released from the system in normal use.” The 2009 model text is reproduced here; the definition that binds your project is the one in the edition your jurisdiction has adopted, as amended locally.
Which parts of the code depend on metal hydride storage system?
In this corpus the term is used across 2 chapters, led by Flammable Gases and Flammable Cryogenic Fluids in the IFC 2009. Those are the sections whose scope moves if the definition is amended locally, so read them together with Chapter 2 rather than on their own.
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