# Limit Control: Building Code Definition

> How the IMC 2009 define limit control, where the wording differs, and which chapters depend on the term.

- Canonical: https://harth.build/resources/glossary/limit-control/
- 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 | IMC 2009 (2009 editions transcribed in this corpus) |
| Primary source | IMC 2009 Definitions (model text, not a jurisdiction's adopted text) |
| Chapters using the term | 3 (counted across the codes hosted here) |
| Wording identical across codes | Single code (compare before citing one code's wording under another) |

## Direct answer

Limit control is a defined term in the International Mechanical Code (IMC) 2009, in Definitions. The code's own words are: “A device responsive to changes in pressure, temperature or level for turning on, shutting off or throttling the gas supply to an appliance.” No other I-Code in this corpus defines it, so the IMC 2009 definition is the one to work from. The term is used in 3 chapters of this corpus, most often in Hazardous Materials-general Provisions (IFC 2009), Cryogenic Fluids (IFC 2009), Definitions (IMC 2009). These pages transcribe the 2009 model text; verify the definition against the edition and amendments your authority having jurisdiction has adopted. Record the jurisdiction, the adopted edition, the application date and any local amendment that rewrites the definition before you use it on a live project, because a term redefined by amendment changes every requirement that depends on it.

*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?

**Limit Control** — IMC 2009, Definitions:

> A device responsive to changes in pressure, temperature or level for turning on, shutting off or throttling the gas supply to an appliance.

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

*How the IMC 2009 define limit control, where the wording differs, and which chapters depend on the term.*

## What must be verified before using this guidance?

**Limit Control** is defined once in this corpus, in the [Definitions](https://harth.build/resources/building-codes/us-states/new-hampshire/imc-2009/definitions.md) chapter of the International Mechanical Code (IMC) 2009:

> A device responsive to changes in pressure, temperature or level for turning on, shutting off or throttling the gas supply to an appliance.

## Where limit control is used in the code

The term appears in 3 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 | 16 |
| [Cryogenic Fluids](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/cryogenic-fluids.md) | IFC 2009 | 6 |
| [Definitions](https://harth.build/resources/building-codes/us-states/new-hampshire/imc-2009/definitions.md) | IMC 2009 | 1 |

### The term in use

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

> Atmospheric tanks having a capacity greater than 500 gallons (1893 L) and which contain hazardous material liquids shall be equipped with a liquid-level limit control or other approved means to prevent overfilling of the tank.

— [IFC 2009 §2703.2.7](https://harth.build/resources/building-codes/us-states/rhode-island/ifc-2009/hazardous-materials-general-provisions.md)


## The terms limit control is built out of

The definition above leans on 2 other defined terms. Each carries its own code definition, and a local amendment to any of them changes what limit control covers:

- **[Appliance](https://harth.build/resources/glossary/appliance.md)** — IRC 2009: Utilization equipment, normally built in standardized sizes or types, that is installed or connected as a unit to perform one or more functions such as clothes washing, air conditioning, food mixing, deep frying, etc.
- **[Device](https://harth.build/resources/glossary/device.md)** — IRC 2009: Aunit of an electrical system that carries or controls electrical energy as it principal function.

## Limit Control: 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 IMC | Definitions | |
| Re-check the requirement that uses it | Hazardous Materials-general Provisions (IFC 2009) | |
| Re-check the requirement that uses it | Cryogenic Fluids (IFC 2009) | |
| Re-check the requirement that uses it | Definitions (IMC 2009) | |
| Confirm the dependent definition | Appliance | |
| Confirm the dependent definition | Device | |
| 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)
- [Appliance: Building Code Definition](https://harth.build/resources/glossary/appliance.md)
- [Device: Building Code Definition](https://harth.build/resources/glossary/device.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 limit control?

The International Mechanical Code (IMC) 2009 defines it in Definitions as: “A device responsive to changes in pressure, temperature or level for turning on, shutting off or throttling the gas supply to an appliance.” 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 limit control?

In this corpus the term is used across 3 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 "limiting distance" in the BC building code?

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 limit control, which the IMC 2009 defines as “A device responsive to changes in pressure, temperature or level for turning on, shutting off or throttling the gas supply to an appliance.” — read both before applying either, and confirm the wording in the edition your jurisdiction has adopted.

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

Control Area is a separate defined term. The IBC 2009 defines it 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.” That is not the same as limit control, which the IMC 2009 defines as “A device responsive to changes in pressure, temperature or level for turning on, shutting off or throttling the gas supply to an appliance.” — read both before applying either, and confirm the wording in the edition your jurisdiction has adopted.

### What is a limit control?

In the 2009 I-Codes hosted here it is a defined term rather than a description. The IMC 2009 states, in Definitions: “A device responsive to changes in pressure, temperature or level for turning on, shutting off or throttling the gas supply to an appliance.” It is defined in IMC 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.

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