• Codes
  • Features

    Features Overview

    Go to features
    Reference

    Reference.

    A reliable and up-to-date source of codes.
    Research

    Research.

    Rapidly and efficiently calculate project parameters.
    Collaboration

    Collaboration.

    Get everyone on the same page and streamline code research.
    Workflows
    Architects General Contractor Building Official & Plans Examiner Inspectors Owner Subcontractors Code Consultants
  • Pricing
  • Login
  • Sign Up
Sign Up
Login
  • Code Library
  • Features
  • Pricing
  • About
  • Careers
  • Help
  • Contact
  • Terms
  • Privacy
Sign Up
Upgrade to Premium
Code calculators: Code Calculators automatically generates a detailed list of requirements.
REFERENCE
Amendment Styling
Industry-leading search
Suggested code sections
Code diagrams
RESEARCH
Code calculators
Filter by topic
Code compare
Code sheet exports
COLLABORATION
Team projects
Bookmarks
Comments
START 2 WEEK FREE TRIAL
Have an account? Sign in
// CODE SNIPPET

Section 6004 Highly Toxic and Toxic Compressed Gases

California Fire Code 2019 > 60 Highly Toxic and Toxic Materials > 6004 Highly Toxic and Toxic Compressed Gases
JUMP TO FULL CODE CHAPTER

6004.1 General

The storage and use of highly toxic and toxic compressed gases shall comply with this section.

6004.1.1 Special Limitations for Indoor Storage and Use by Occupancy

The indoor storage and use of highly toxic and toxic compressed gases in certain occupancies shall be subject to the limitations contained in Sections 6004.1.1.1 through 6004.1.1.3.

6004.1.1.1 Group A, E, I or U Occupancies

Toxic and highly toxic compressed gases shall not be stored or used within Group A, E, I or U occupancies.

Exception: Cylinders not exceeding 20 cubic feet (0.566 m3) at normal temperature and pressure (NTP) are allowed within gas cabinets or fume hoods.

6004.1.1.2 Group R Occupancies

Toxic and highly toxic compressed gases shall not be stored or used in Group R occupancies.

6004.1.1.3 Offices, Retail Sales and Classrooms

Toxic and highly toxic compressed gases shall not be stored or used in offices, retail sales or classroom portions of Group B, F, M or S occupancies.

Exception: In classrooms of Group B occupancies, cylinders with a capacity not exceeding 20 cubic feet (0.566 m3) at NTP are allowed in gas cabinets or fume hoods.

6004.1.2 Gas Cabinets

Gas cabinets containing highly toxic or toxic compressed gases shall comply with Section 5003.8.6 and the following requirements:

  1. The average ventilation velocity at the face of gas cabinet access ports or windows shall be not less than 200 feet per minute (1.02 m/s) with not less than 150 feet per minute (0.76 m/s) at any point of the access port or window.
  2. Gas cabinets shall be connected to an exhaust system.
  3. Gas cabinets shall not be used as the sole means of exhaust for any room or area.
  4. The maximum number of cylinders located in a single gas cabinet shall not exceed three, except that cabinets containing cylinders not exceeding 1 pound (0.454 kg) net contents are allowed to contain up to 100 cylinders.
  5. Gas cabinets required by Section 6004.2 or 6004.3 shall be equipped with an approved automatic sprinkler system in accordance with Section 903.3.1.1. Alternative fire-extinguishing systems shall not be used.

6004.1.3 Exhausted Enclosures

Exhausted enclosures containing highly toxic or toxic compressed gases shall comply with Section 5003.8.5 and the following requirements:

  1. The average ventilation velocity at the face of the enclosure shall be not less than 200 feet per minute (1.02 m/s) with not less than 150 feet per minute (0.76 m/s).
  2. Exhausted enclosures shall be connected to an exhaust system.
  3. Exhausted enclosures shall not be used as the sole means of exhaust for any room or area.
  4. Exhausted enclosures required by Section 6004.2 or 6004.3 shall be equipped with an approved automatic sprinkler system in accordance with Section 903.3.1.1. Alternative fire-extinguishing systems shall not be used.

6004.2 Indoor Storage and Use

The indoor storage and use of highly toxic or toxic compressed gases shall be in accordance with Sections 6004.2.1 through 6004.2.2.10.3.

6004.2.1 Applicability

The applicability of regulations governing the indoor storage and use of highly toxic and toxic compressed gases shall be as set forth in Sections 6004.2.1.1 through 6004.2.1.3.

6004.2.1.1 Quantities Not Exceeding the Maximum Allowable Quantity Per Control Area

The indoor storage or use of highly toxic and toxic gases in amounts not exceeding the maximum allowable quantity per control area set forth in Table 5003.1.1(2) shall be in accordance with Sections 5001, 5003, 6001 and 6004.1.

6004.2.1.2 Quantities Exceeding the Maximum Allowable Quantity Per Control Area

The indoor storage or use of highly toxic and toxic gases in amounts exceeding the maximum allowable quantity per control area set forth in Table 5003.1.1(2) shall be in accordance with Sections 6001, 6004.1, 6004.2 and Chapter 50.

6004.2.1.3 Ozone Gas Generators

The indoor use of ozone gas-generating equipment shall be in accordance with Section 6005.

6004.2.2 General Indoor Requirements

The general requirements applicable to the indoor storage and use of highly toxic and toxic compressed gases shall be in accordance with Sections 6004.2.2.1 through 6004.2.2.10.3.

6004.2.2.1 Cylinder and Tank Location

Cylinders shall be located within gas cabinets, exhausted enclosures or gas rooms. Portable and stationary tanks shall be located within gas rooms or exhausted enclosures.

6004.2.2.2 Ventilated Areas

The room or area in which gas cabinets or exhausted enclosures are located shall be provided with exhaust ventilation. Gas cabinets or exhausted enclosures shall not be used as the sole means of exhaust for any room or area.

6004.2.2.3 Leaking Cylinders and Tanks

One or more gas cabinets or exhausted enclosures shall be provided to handle leaking cylinders, containers or tanks.

Exceptions:

  1. Where cylinders, containers or tanks are located within gas cabinets or exhausted enclosures.
  2. Where approved containment vessels or containment systems are provided in accordance with all of the following:

    1. 2.1. Containment vessels or containment systems shall be capable of fully containing or terminating a release.
    2. 2.2. Trained personnel shall be available at an approved location.
    3. 2.3. Containment vessels or containment systems shall be capable of being transported to the leaking cylinder, container or tank.

6004.2.2.3.1 Location

Gas cabinets and exhausted enclosures shall be located in gas rooms and connected to an exhaust system.

6004.2.2.4 Local Exhaust for Portable Tanks

A means of local exhaust shall be provided to capture leaks from portable tanks. The local exhaust shall consist of portable ducts or collection systems designed to be applied to the site of a leak in a valve or fitting on the tank. The local exhaust system shall be located in a gas room. Exhaust shall be directed to a treatment system in accordance with Section 6004.2.2.7.

6004.2.2.5 Piping and Controls—Stationary Tanks

In addition to the requirements of Section 5003.2.2, piping and controls on stationary tanks shall comply with the following requirements:

  1. Pressure relief devices shall be vented to a treatment system designed in accordance with Section 6004.2.2.7.

    Exception: Pressure relief devices on outdoor tanks provided exclusively for relieving pressure due to fire exposure are not required to be vented to a treatment system provided that:

    1. The material in the tank is not flammable.
    2. The tank is not located in a diked area with other tanks containing combustible materials.
    3. The tank is located not less than 30 feet (9144 mm) from combustible materials or structures or is shielded by a fire barrier complying with Section 6004.3.2.1.1.
  2. Filling or dispensing connections shall be provided with a means of local exhaust. Such exhaust shall be designed to capture fumes and vapors. The exhaust shall be directed to a treatment system in accordance with Section 6004.2.2.7.
  3. Stationary tanks shall be provided with a means of excess flow control on all tank inlet or outlet connections.

    Exceptions:

    1. Inlet connections designed to prevent backflow.
    2. Pressure relief devices.

6004.2.2.6 Gas Rooms

Gas rooms shall comply with Section 5003.8.4 and both of the following requirements:

  1. The exhaust ventilation from gas rooms shall be directed to an exhaust system.
  2. Gas rooms shall be equipped with an approved automatic sprinkler system. Alternative fire-extinguishing systems shall not be used.

6004.2.2.7 Treatment Systems

The exhaust ventilation from gas cabinets, exhausted enclosures and gas rooms, and local exhaust systems required in Sections 6004.2.2.4 and 6004.2.2.5 shall be directed to a treatment system. The treatment system shall be utilized to handle the accidental release of gas and to process exhaust ventilation. The treatment system shall be designed in accordance with Sections 6004.2.2.7.1 through 6004.2.2.7.5 and Section 510 of the California Mechanical Code.

Exceptions:

  1. Highly toxic and toxic gases—storage. A treatment system is not required for cylinders, containers and tanks in storage where all of the following controls are provided:

    1. 1.1. Valve outlets are equipped with gas-tight outlet plugs or caps.
    2. 1.2. Handwheel-operated valves have handles secured to prevent movement.
    3. 1.3. Approved containment vessels or containment systems are provided in accordance with Section 6004.2.2.3.
  2. Toxic gases—use. Treatment systems are not required for toxic gases supplied by cylinders or portable tanks not exceeding 1,700 pounds (772 kg) water capacity where a gas detection system complying with Section 6004.2.2.10 and listed or approved automatic-closing failsafe valves are provided. The gas detection system shall have a sensing interval not exceeding 5 minutes. Automatic-closing failsafe valves shall be located immediately adjacent to cylinder valves and shall close when gas is detected at the permissible exposure limit (PEL) by a gas sensor monitoring the exhaust system at the point of discharge from the gas cabinet, exhausted enclosure, ventilated enclosure or gas room.

6004.2.2.7.1 Design

Treatment systems shall be capable of diluting, adsorbing, absorbing, containing, neutralizing, burning or otherwise processing the contents of the largest single vessel of compressed gas. Where a total containment system is used, the system shall be designed to handle the maximum anticipated pressure of release to the system when it reaches equilibrium.

6004.2.2.7.2 Performance

Treatment systems shall be designed to reduce the maximum allowable discharge concentrations of the gas to one-half immediate by dangerous to life and health (IDLH) at the point of discharge to the atmosphere. Where more than one gas is emitted to the treatment system, the treatment system shall be designed to handle the worst-case release based on the release rate, the quantity and the IDLH for all compressed gases stored or used.

6004.2.2.7.3 Sizing

Treatment systems shall be sized to process the maximum worst-case release of gas based on the maximum flow rate of release from the largest vessel utilized. The entire contents of the largest compressed gas vessel shall be considered.

6004.2.2.7.4 Stationary Tanks

Stationary tanks shall be labeled with the maximum rate of release for the compressed gas contained based on valves or fittings that are inserted directly into the tank. Where multiple valves or fittings are provided, the maximum flow rate of release for valves or fittings with the highest flow rate shall be indicated. Where liquefied compressed gases are in contact with valves or fittings, the liquid flow rate shall be utilized for computation purposes. Flow rates indicated on the label shall be converted to cubic feet per minute (cfm/min) (m3/s) of gas at normal temperature and pressure (NTP).

6004.2.2.7.5 Portable Tanks and Cylinders

The maximum flow rate of release for portable tanks and cylinders shall be calculated based on the total release from the cylinder or tank within the time specified in Table 6004.2.2.7.5. Where portable tanks or cylinders are equipped with approved excess flow or reduced flow valves, the worst-case release shall be determined by the maximum achievable flow from the valve as determined by the valve manufacturer or compressed gas supplier. Reduced flow and excess flow valves shall be permanently marked by the valve manufacturer to indicate the maximum design flow rate. Such markings shall indicate the flow rate for air under normal temperature and pressure.

TABLE 6004.2.2.7.5

RATE OF RELEASE FOR CYLINDERS AND PORTABLE TANKS

VESSEL TYPE NONLIQUEFIED (minutes) LIQUEFIED (minutes)
Containers 5 30
Portable tanks 40 240

6004.2.2.8 Emergency Power

Emergency power shall be provided for the following systems in accordance with Section 604:

  1. Exhaust ventilation system.
  2. Treatment system.
  3. Gas detection system.
  4. Smoke detection system.
  5. Temperature control system.
  6. Fire alarm system.
  7. Emergency alarm system.

6004.2.2.8.1 Fail-Safe Engineered Systems

Emergency power shall not be required for mechanical exhaust ventilation, treatment systems and temperature control systems where approved fail-safe engineered systems are installed.

6004.2.2.9 Automatic Fire Detection System—Highly Toxic Compressed Gases

An approved automatic fire detection system shall be installed in rooms or areas where highly toxic compressed gases are stored or used. Activation of the detection system shall sound a local alarm. The fire detection system shall comply with Section 907.

6004.2.2.10 Gas Detection System

A gas detection system complying with Section 916 shall be provided to detect the presence of gas at or below the PEL or ceiling limit of the gas for which detection is provided. The system shall be capable of monitoring the discharge from the treatment system at or below one-half the IDLH limit and shall initiate a response in accordance with Sections 6004.2.2.10.1 through 6004.2.2.10.3 if the gas detection alarm is activated.

Exception: A gas detection system is not required for toxic gases when the physiological warning threshold level for the gas is at a level below the accepted PEL for the gas.

6004.2.2.10.1 Alarms

The gas detection system shall initiate a local alarm and transmit a signal to a constantly attended control station when a short term hazard condition is detected. The alarm shall be both audible and visible and shall provide warning both inside and outside the area where gas is detected. The audible alarm shall be distinct from all other alarms.

Exception: Signal transmission to a constantly attended control station is not required where not more than one cylinder of highly toxic or toxic gas is stored.

6004.2.2.10.2 Shut Off of Gas Supply

The gas-detection system shall automatically close the shutoff valve at the source on gas supply piping and tubing related to the system being monitored for whichever gas is detected.

Exception: Automatic shutdown is not required for reactors utilized for the production of highly toxic or toxic compressed gases where such reactors are:

  1. Operated at pressures less than 15 pounds per square inch gauge (psig) (103.4 kPa).
  2. Constantly attended.
  3. Provided with emergency shutoff valves that have ready access.
SEE MORE

Related Code Sections


Section 6004 Highly Toxic and Toxic Materials, Highly Toxic and Toxic Compressed Gases
The storage and use of highly toxic and toxic compressed gases shall comply with this section ...
California Fire Code 2019 > 60 Highly Toxic and Toxic Materials > 6004 Highly Toxic and Toxic Compressed Gases
Section 6004 Highly Toxic and Toxic Materials, Highly Toxic and Toxic Compressed Gases
The storage and use of highly toxic and toxic compressed gases shall comply with this section ...
California Fire Code 2016 > 60 Highly Toxic and Toxic Materials > 6004 Highly Toxic and Toxic Compressed Gases
6004.2 Highly Toxic and Toxic Materials, Indoor Storage and Use
The indoor storage and use of highly toxic or toxic compressed gases shall be in accordance with Sections 6004.2.1 through 6004.2.2.10.4 ...
California Fire Code 2016 > 60 Highly Toxic and Toxic Materials > 6004 Highly Toxic and Toxic Compressed Gases > 6004.2 Indoor Storage and Use
6004.1.1 Highly Toxic and Toxic Materials, Special Limitations for Indoor Storage and Use by Occupancy
The indoor storage and use of highly toxic and toxic compressed gases in certain occupancies shall be subject to the limitations contained ...
California Fire Code 2019 > 60 Highly Toxic and Toxic Materials > 6004 Highly Toxic and Toxic Compressed Gases > 6004.1 General > 6004.1.1 Special Limitations for Indoor Storage and Use by Occupancy
6004.1.1 Highly Toxic and Toxic Materials, Special Limitations for Indoor Storage and Use by Occupancy
The indoor storage and use of highly toxic and toxic compressed gases in certain occupancies shall be subject to the limitations contained ...
California Fire Code 2016 > 60 Highly Toxic and Toxic Materials > 6004 Highly Toxic and Toxic Compressed Gases > 6004.1 General > 6004.1.1 Special Limitations for Indoor Storage and Use by Occupancy
Help Contact Us Privacy Terms
Code Compare
Code Compare
Highlight differences between any two building codes.
Code sheet exports
Code sheet exports
Generate a code sheet that integrates with your drawing set.
Code diagrams
Code diagrams
Unpack the code through illustrations and descriptions.
Shared projects
Shared projects
Projects provide a dedicated space to collaborate on code research.
Code Calculators
Code Calculators
Code calculators automatically generate a detailed list of requirements.
Search
Search
Don't miss relevant code. Quickly locate sections across your jurisdiction.
UpCodes Premium
Leverage the most sophisticated code compliance platform.
TRY FREE FOR TWO WEEKS VISIT PRICING
UpCodes Premium
Leverage the full code compliance platform.
START 2 WEEK FREE TRIAL LEARN MORE