UC San Diego SearchMenu

Compressed Gas: Hazard Class Requirements Matrix

Follow safety requirements for the hazard class of your material.

Requirements for safe use of a hazardous gas are determined by the hazard class of the gas.

  1. Determine the Hazard Class of your material.
  2. Then follow the appropriate requirements below.

Click on the requirement for a full description.

Requirements Class IV Class III Class II Class I
Exhausted enclosures (gas cabinets or fume hoods)   C1 X X

Treatment to 1/2 IDLH at atmosphere

  X X X
Leak check (of installed system)   X X X
Emergency response plan, team, and drills   X X X
Flow-limiting device or flow-restricting orifice   C1 X X
Use in sprinkled spaces   X X X
Documented annual maintenance   X X X
Compatible piping   X X X
Purge system   C1 X X
Detector system C2 C1 C1 X
Emergency alarms (and explanatory signs)   C1 X X
Welded, compatible piping     X X
Local shut-off     X X
Interlocks     X X
Emergency power (alarm, detector, ventilation)     X X
Monitored secondary containment       C1
Auto shut-off (manual or detector triggered)     X X
Exhaust flow alarm       X

C1 – These systems are conditional and will be determined by the EH&S Chemical Hygiene Officer, (858) 822-1579.

C2 – An oxygen sensor may be required if it is determined that the location where this compressed gas is being used or stored presents a risk of asphyxiation. Advanced Micro Instruments Inc. makes a cost effective oxygen sensor.

Notice: Disposal of hazardous waste using sinks, intentional evaporation, or as regular trash is against the law. Campus laboratories must abide by strict state and federal waste disposal requirements. You may be held liable for violations of applicable laws.