# Control Area: Building Code Definition

> How the IBC 2009, IFC 2009 define control area, where the wording differs, and which chapters depend on the term.

- Canonical: https://harth.build/resources/glossary/control-area/
- Last updated: 2026-09-07
- Data source: 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.

## Key facts

| Fact | Value |
| --- | --- |
| Defined in | IBC 2009, IFC 2009 (2009 editions transcribed in this corpus) |
| Primary source | IBC 2009 Use and Occupancy Classification (model text, not a jurisdiction's adopted text) |
| Chapters using the term | 24 (counted across the codes hosted here) |
| Wording identical across codes | No (compare before citing one code's wording under another) |

## Direct answer

Control area is a defined term in the International Building Code (IBC) 2009, in Use and Occupancy Classification. The code's own words are: “Spaces within a building where quantities of hazardous materials not exceeding the maximum allowable quantities per control area are stored, dispensed, used or handled. See also the definition of "Outdoor control area" in the International Fire Code.” The IFC 2009 defines the same term with different wording, so the controlling text depends on which code governs the question in front of you — the comparison below sets the versions side by side. The term is used in 24 chapters of this corpus, most often in Hazardous Materials-general Provisions (IFC 2009), Flammable and Combustible Liquids (IFC 2009), Special Detailed Requirements Based on Use and Occupancy (IBC 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](https://nz.linkedin.com/in/barrington), Harth founder and architectural technology specialist · Published 2026-09-07 · Updated 2026-09-07.*

## What does this term mean?

**Control Area** — IBC 2009, Use and Occupancy Classification:

> Spaces within a building where quantities of hazardous materials not exceeding the maximum allowable quantities per control area are stored, dispensed, used or handled. See also the definition of "Outdoor control area" in the International Fire Code.

![Labeled code-term definition diagram: Control Area: Building Code Definition](https://efwwel0vyt9vy5so.public.blob.vercel-storage.com/images/glossary/control-area/diagram-1344.webp)

*How the IBC 2009, IFC 2009 define control area, where the wording differs, and which chapters depend on the term.*

## What must be verified before using this guidance?

Two of the I-Codes in this corpus define **Control Area**, and the wording is not identical — read the version that governs your question.

| Code | Where it is defined | Definition |
| --- | --- | --- |
| IBC 2009 | [Use and Occupancy Classification](https://harth.build/resources/building-codes/us-states/maryland/ibc-2009/use-and-occupancy-classification.md) | Spaces within a building where quantities of hazardous materials not exceeding the maximum allowable quantities per control area are stored, dispensed, used or handled. See also the definition of "Outdoor control area" in the International Fire Code. |
| IFC 2009 | [Hazardous Materials-general Provisions](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/hazardous-materials-general-provisions.md) | Spaces within a building where quantities of hazardous materials not exceeding the maximum allowable quantities per control area are stored, dispensed, used or handled. See also the definition of "Outdoor control area." |

## Where control area is used in the code

The term appears in 24 chapters of the 2009 I-Codes hosted here. The chapters that lean on it hardest are the ones to read next.

| Chapter | Code | Mentions |
| --- | --- | --- |
| [Hazardous Materials-general Provisions](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/hazardous-materials-general-provisions.md) | IFC 2009 | 122 |
| [Flammable and Combustible Liquids](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/flammable-and-combustible-liquids.md) | IFC 2009 | 60 |
| [Special Detailed Requirements Based on Use and Occupancy](https://harth.build/resources/building-codes/us-states/maryland/ibc-2009/special-detailed-requirements-based-on-use-and-occupancy.md) | IBC 2009 | 49 |
| [Highly Toxic and Toxic Materials](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/highly-toxic-and-toxic-materials.md) | IFC 2009 | 40 |
| [Exhaust Systems](https://harth.build/resources/building-codes/us-states/new-hampshire/imc-2009/exhaust-systems.md) | IMC 2009 | 26 |
| [Unstable (reactive) Materials](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/unstable-reactive-materials.md) | IFC 2009 | 15 |
| [Flammable Gases and Flammable Cryogenic Fluids](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/flammable-gases-and-flammable-cryogenic-fluids.md) | IFC 2009 | 14 |
| [Flammable Solids](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/flammable-solids.md) | IFC 2009 | 14 |
| [Oxidizers, Oxidizing Gases and Oxidizing Cryogenic Fluids](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/oxidizers-oxidizing-gases-and-oxidizing-cryogenic-fluids.md) | IFC 2009 | 13 |
| [Corrosive Materials](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/corrosive-materials.md) | IFC 2009 | 12 |
| [Organic Peroxides](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/organic-peroxides.md) | IFC 2009 | 12 |
| [Water-reactive Solids and Liquids](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/water-reactive-solids-and-liquids.md) | IFC 2009 | 11 |

_12 further chapters mention the term._

### The term in use

How the code actually writes about control area, quoted from the 2009 text hosted here:

> The maximum allowable quantityper control area shall be as specified in Tables 2703.1.1(1) through 2703.1.1(4).

— [IFC 2009 §2703.1.1](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/hazardous-materials-general-provisions.md)

> Where the maximum allowable quantityper control area is exceeded, and when required by Section 2704.2, rooms, buildings or areas used for storage, dispensing, use, mixing or handling of Class I, II and IlIA liquids shall be provided with spill control and secondary containment in accordance with Section 2704.2.

— [IFC 2009 §3403.4](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/flammable-and-combustible-liquids.md)

> The floor assembly of the control area and the construction supporting the floor of the control area shall have a minimum 2-hour fire-resistance rating.

— [IBC 2009 §414.2.4](https://harth.build/resources/building-codes/us-states/maryland/ibc-2009/special-detailed-requirements-based-on-use-and-occupancy.md)


## The terms control area is built out of

The definition above leans on 4 other defined terms. Each carries its own code definition, and a local amendment to any of them changes what control area covers:

- **[Outdoor Control Area](https://harth.build/resources/glossary/outdoor-control-area.md)** — IFC 2009: An outdoor area that contains hazardous materials in amounts not exceeding the maximum allowable quantities of table 2703.1.1 (3) or 2703.1.1 (4).
- **[Hazardous Materials](https://harth.build/resources/glossary/hazardous-materials.md)** — IBC 2009: Those chemicals or substances that are physical hazards or health hazards as defined and classified in this section and the International Fire Code, whether the materials are in usable or waste condition.
- **[Building](https://harth.build/resources/glossary/building.md)** — IBC 2009: Any structure used or intended for supporting or sheltering any use or occupancy.
- **[Control](https://harth.build/resources/glossary/control.md)** — IRC 2009: A manual or automatic device designed to regulate the gas, air, water or electrical supply to, or operation of, a mechanical system.

## Control Area: what to open, and in what order

Every row is a document this term depends on. The [ICC code library](https://codes.iccsafe.org/codes) and the [ICC adoption maps](https://www.iccsafe.org/advocacy/code-adoption-maps/) cover the middle rows.

| Check | Where | Confirmed |
| --- | --- | --- |
| Read the definition in the adopted IBC | Use and Occupancy Classification | |
| Read the definition in the adopted IFC | Hazardous Materials-general Provisions | |
| Re-check the requirement that uses it | Hazardous Materials-general Provisions (IFC 2009) | |
| Re-check the requirement that uses it | Flammable and Combustible Liquids (IFC 2009) | |
| Re-check the requirement that uses it | Special Detailed Requirements Based on Use and Occupancy (IBC 2009) | |
| Re-check the requirement that uses it | Highly Toxic and Toxic Materials (IFC 2009) | |
| Confirm the dependent definition | Outdoor Control Area | |
| Confirm the dependent definition | Hazardous Materials | |
| Confirm the dependent definition | Building | |
| 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](https://harth.build/resources/glossary.md)
- [Outdoor Control Area: Building Code Definition](https://harth.build/resources/glossary/outdoor-control-area.md)
- [Hazardous Materials: Building Code Definition](https://harth.build/resources/glossary/hazardous-materials.md)
- [Building: Building Code Definition](https://harth.build/resources/glossary/building.md)
- [Control: Building Code Definition](https://harth.build/resources/glossary/control.md)

## 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](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.

### Source links

- [codes.iccsafe.org](https://codes.iccsafe.org/codes)

- [iccsafe.org](https://www.iccsafe.org/advocacy/code-adoption-maps/)

## Frequently asked questions

### What is the code definition of control area?

The International Building Code (IBC) 2009 defines it in Use and Occupancy Classification as: “Spaces within a building where quantities of hazardous materials not exceeding the maximum allowable quantities per control area are stored, dispensed, used or handled. See also the definition of "Outdoor control area" in the International Fire Code.” 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 control area?

In this corpus the term is used across 24 chapters, led by Hazardous Materials-general Provisions 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.

### What is the definition of a control area?

In the 2009 I-Codes hosted here it is a defined term rather than a description. The IBC 2009 states, in Use and Occupancy Classification: “Spaces within a building where quantities of hazardous materials not exceeding the maximum allowable quantities per control area are stored, dispensed, used or handled. See also the definition of "Outdoor control area" in the International Fire Code.” It is defined in IBC 2009, IFC 2009. Because it is a defined term, whatever the adopted edition says it means is what every section using it means — so check Chapter 2 of that edition and any local amendment before relying on this wording.

### What is the definition of building area according to the IBC?

Building is a separate defined term. The IBC 2009 defines it as: “Any structure used or intended for supporting or sheltering any use or occupancy.” That is not the same as control area, which the IBC 2009 defines as “Spaces within a building where quantities of hazardous materials not exceeding the maximum allowable quantities per control area are stored, dispensed, used or handled. See also the definition of "Outdoor control area" in the International Fire Code.” — read both before applying either, and confirm the wording in the edition your jurisdiction has adopted.

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