- Display and storage in Group M and storage in Group S occupancies complying with Section 5003.11.
- Conditions involving pesticides or agricultural products as follows:
- 2.1. Application and release of pesticide, agricultural products and materials intended for use in weed abatement, erosion control, soil amendment or similar applications when applied in accordance with the manufacturer’s instruction and label directions.
- 2.2. Transportation of pesticides in compliance with the Federal Hazardous Materials Transportation Act and regulations thereunder.
- 2.3. Storage in dwellings or private garages of pesticides registered by the U.S. Environmental Protection Agency to be utilized in and around the home, garden, pool, spa and patio.
- The average ventilation velocity at the face of gas cabinet access ports or windows shall not be less than 200 feet per minute (1.02 m/s) with a minimum of 150 feet per minute (0.76 m/s) at any point of the access port or window.
- Gas cabinets shall be connected to an exhaust system.
- Gas cabinets shall not be used as the sole means of exhaust for any room or area.
- 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.
- 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.
- The average ventilation velocity at the face of the enclosure shall not be less than 200 feet per minute (1.02 m/s) with a minimum of 150 feet per minute (0.76 m/s).
- Exhausted enclosures shall be connected to an exhaust system.
- Exhausted enclosures shall not be used as the sole means of exhaust for any room or area.
- 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.
- Where cylinders, containers or tanks are located within gas cabinets or exhausted enclosures.
- Where approved containment vessels or containment systems are provided in accordance with all of the following:
- 2.1. Containment vessels or containment systems shall be capable of fully containing or terminating a release.
- 2.2. Trained personnel shall be available at an approved location.
- 2.3. Containment vessels or containment systems shall be capable of being transported to the leaking cylinder, container or tank.
- Pressure relief devices shall be vented to a treatment system designed in accordance with Section 6004.2.2.7.
- 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.
- Stationary tanks shall be provided with a means of excess flow control on all tank inlet or outlet connections.
- Inlet connections designed to prevent backflow.
- Pressure relief devices.
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 International Mechanical Code.
- Highly toxic and toxic gases—storage. A treatment system is not required for cylinders, containers and tanks in storage when all of the following controls are provided:
- 1.1. Valve outlets are equipped with gas-tight outlet plugs or caps.
- 1.2. Handwheel-operated valves have handles secured to prevent movement.
- 1.3. Approved containment vessels or containment systems are provided in accordance with Section 6004.2.2.3.
- 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 when the following are provided:
- 2.1. A listed or approved gas detection system with a sensing interval not exceeding 5 minutes.
- 2.2. A listed or approved automatic-closing fail-safe valve located immediately adjacent to cylinder valves. The fail-safe valve shall close when gas is detected at the permissible exposure limit (PEL) by a gas detection system monitoring the exhaust system at the point of discharge from the gas cabinet, exhausted enclosure, ventilated enclosure or gas room. The gas detection system shall comply with Section 6004.2.2.10.
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. When 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.
- Exhaust ventilation system.
- Treatment system.
- Gas detection system.
- Smoke detection system.
- Temperature control system.
- Fire alarm system.
- Emergency alarm system.
A gas detection system 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.
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 visual and audible and shall provide warning both inside and outside the area where gas is detected. The audible alarm shall be distinct from all other alarms.
- Operated at pressures less than 15 pounds per square inch gauge (psig) (103.4 kPa).
- Constantly attended.
- Provided with readily accessible emergency shutoff valves.
Automatic closure of shutoff valves shall be in accordance with the following:
- When the gas-detection sampling point initiating the gas detection system alarm is within a gas cabinet or exhausted enclosure, the shutoff valve in the gas cabinet or exhausted enclosure for the specific gas detected shall automatically close.
- Where the gas-detection sampling point initiating the gas detection system alarm is within a gas room and compressed gas containers are not in gas cabinets or exhausted enclosures, the shutoff valves on all gas lines for the specific gas detected shall automatically close.
- Where the gas-detection sampling point initiating the gas detection system alarm is within a piping distribution manifold enclosure, the shutoff valve for the compressed container of specific gas detected supplying the manifold shall automatically close.
Exception: When the gas-detection sampling point initiating the gas-detection system alarm is at a use location or within a gas valve enclosure of a branch line downstream of a piping distribution manifold, the shutoff valve in the gas valve enclosure for the branch line located in the piping distribution manifold enclosure shall automatically close.
Exception: Compressed gases located in gas cabinets complying with Sections 5003.8.6 and 6004.1.2 and located 5 feet (1524 mm) or more from buildings and 25 feet (7620 mm) or more from an exit discharge.
Outdoor storage or use of highly toxic or toxic compressed gases shall not be located within 75 feet (22 860 mm) of a lot line, public street, public alley, public way, exit discharge or building not associated with the manufacture or distribution of such gases, unless all of the following conditions are met:
- Storage is shielded by a 2-hour fire barrier which interrupts the line of sight between the storage and the exposure.
- The 2-hour fire barrier shall be located at least 5 feet (1524 mm) from any exposure.
- The 2-hour fire barrier shall not have more than two sides at approximately 90-degree (1.57 rad) directions, or three sides with connecting angles of approximately 135 degrees (2.36 rad).
Weather protection in accordance with Section 5004.13 shall be provided for portable tanks and cylinders located outdoors and not within gas cabinets or exhausted enclosures. The storage area shall be equipped with an approved automatic sprinkler system in accordance with Section 903.3.1.1.
Exception: An automatic sprinkler system is not required when:
- All materials under the weather protection structure, including hazardous materials and the containers in which they are stored, are non-combustible.
- The weather protection structure is located not less than 30 feet (9144 mm) from combustible materials or structures or is separated from such materials or structures using a fire barrier complying with Section 6004.3.2.1.1.
Cabinets shall be braced for seismic activity in accordance with the International Building Code.
Cabinets shall be mechanically ventilated in accordance with the International Mechanical Code with a minimum of six air changes per hour.
The average velocity of ventilation at makeup air openings with cabinet doors closed shall not be less than 200 feet per minute (1.02 m/s).
Ozone gas generator rooms shall be mechanically ventilated in accordance with the International Mechanical Code with a minimum of six air changes per hour. Ozone gas generator rooms shall be equipped with a continuous gas detection system that will shut off the generator and sound a local alarm when concentrations above the permissible exposure limit occur.
Ozone gas generator rooms shall not be normally occupied, and such rooms shall be kept free of combustible and hazardous material storage. Room access doors shall display an approved sign stating: OZONE GAS GENERATOR—HIGHLY TOXIC—OXIDIZER.
Ozone gas generators shall be designed to shut down automatically under the following conditions:
- When the dissolved ozone concentration in the water being treated is above saturation when measured at the point where the water is exposed to the atmosphere.
- When the process using generated ozone is shut down.
- When the gas detection system detects ozone.
- Failure of the ventilation system for the cabinet or ozone-generator room.
- Failure of the gas detection system.