Compressed Gas Cylinders

Compressed gas cylinders contain varying pressures of inert, toxic, flammable, oxidizing, corrosive, or combinations of gases. Care in using, handling, and storing compressed gas cylinders is required due to the high potential for severe incidents.

Know gas properties and hazards: Understand the properties, uses, and safety precautions before using any gas or mixture. Consult SDS and manufacturer specification sheets for safety information.

Engineer, assemble, and check equipment properly: Ensure that valves, manifolds, piping, lines, and other equipment is designed and rated for the full pressure and temperature range of operation. Only use fittings as they are specified for by the manufacturer. Inspect and leak check all equipment for using at full capacity.

Utilize facilities engineering: Gas cabinets, facilities exhaust, and fume hoods may be needed for ventilation. Gas cylinder brackets, clamps, restraints and supports may be needed for storage. Monitoring systems may be appropriate for highly hazardous gases.

Wear PPE: Wear suitable protective clothing and equipment. Gloves, eye and face protection, and footwear may be warranted. Some gases may require specialized safety equipment such as self-contained breathing apparatus, air-line respirators.

Follow Regulations: Follow all federal, state, and local regulations that apply to storage and use of compressed gas cylinders.

Use on Campus

Compressed gas cylinders are used regularly in science and engineering buildings, machine shops, and retail and campus dining. Researchers, staff, and outside contractors store and use various types of compressed gases for different reasons. Lab Workers should contact their DCHO or PI when initially thinking of using compressed gas cylinders.

Compressed Gas Hazard Classes

  • Inert
    • Inert gases, such as argon, helium, neon and nitrogen, are not toxic and do not burn or explode. Yet they can cause injury or death if they are present in sufficiently high concentrations. They can displace enough air to reduce oxygen levels.
  • Flammable
    • Acetylene, hydrogen, propane, propylene and methane are all flammable gases referred to as 'fuel gases'. When these gases are mixed with an oxidant and provided with an ignition source, they will burn.
  • Pyrophoric
    • Pyrophoric gases are substances that ignite instantly upon exposure to oxygen.
  • Oxidizing
    • Oxidizing gases may be toxic or corrosive. Depending on the material, route of exposure (inhalation, eye or skin contact, or swallowing) and dose, they could harm the body. Corrosive oxidizers can also attack and destroy metal.
  • Toxic
    • Toxic gases are especially dangerous because they are often invisible and/or odorless. Their physical behavior is not always predictable: ambient temperature, pressure and ventilation patterns significantly influence the behavior of a gas leak. If inhaled at high concentrations can cause central nervous system (CNS) effects. CNS effects can include dizziness, drowsiness, lack of concentration, confusion, headaches, coma and death.
  • Corrosive
    • Corrosive gases will attack and damage human tissue. They will also damage metal and other building materials.


  • All cylinders must be secured to a wall, bench or fixed support using a chain or strap placed 2/3 of the way up. Cylinder stands are an alternative to straps.
  • Cylinders should be strapped individually.
  • Cylinders should not be stored with a regulator attached. Secure the proper gas cap to the threaded portion on the top of the cylinder to protect the valve.*
  • Do not store full and empty cylinders together.
  • Oxidizers and flammable gases should be stored in areas separated by at least 20 feet or by a noncombustible wall.
  • Cylinders should not be stored near radiators or other heat sources. If storage is outdoors, protect cylinders from weather extremes and damp ground to prevent corrosion.
  • No part of a cylinder should be subjected to a temperature higher than 125oF. A flame should never be permitted to come in contact with any part of a compressed gas cylinder.
  • Do not place cylinders where they may become part of an electric circuit.
  • Keep the number of cylinders in a laboratory to a minimum to reduce the fire and toxicity hazards.
  • Lecture bottles should always be returned to the distributor or manufacturer promptly when no longer needed or discarded if at atmospheric pressure.
  • Ensure that the cylinder is properly and prominently labeled as to its contents.
  • NEVER place acetylene cylinders on their side.


  • Use appropriate regulator, compatible manifold materials, and pressure rated tubing and piping for all applications.
  • Consider margins of error for all temperature and pressure ratings on engineering.
  • Wear safety glasses, face shield, and appropriate gloves when manipulating pressurized systems.
  • Never empty a cylinder to less than 25psi.
  • Ensure that the valve is always accessible.


  • Avoid dropping, dragging or sliding cylinders. Use a suitable hand truck or cart equipped with a chain or belt for securing the cylinder to the cart, even for short distances.
  • Do not permit cylinders to strike each other violently. Cylinders should not be used as rollers for moving material or other equipment.
  • Cylinder caps should be left on each cylinder until it has been secured against a wall or bench or placed in a cylinder stand, and is ready for installation of the regulator. Cylinder caps protect the valve on top of the cylinder from damage if knocked.
  • Never tamper with pressure relief devices in valves or cylinders.
  • Use only wrenches or tools provided by the cylinder supplier to remove a cylinder cap or to open a valve. Never use a screwdriver or pliers.
  • Keep the cylinder valve closed except when in use.
  • Position cylinders so that the cylinder valve is accessible at all times.
  • Use compressed gases only in a well-ventilated area. Toxic, flammable and corrosive gases should be carefully handled in a hood or gas cabinet. Proper containment systems should be used and minimum quantities of these products should be kept on-site.
  • When discharging gas into a liquid, a trap or suitable check valve should be used to prevent liquid from getting back into the cylinder or regulator.
  • Where more than one type of gas is in use, label gas lines. This is particularly important when the gas supply is not in the same room or area as the operation using the gases.
  • Do not use the cylinder valve itself to control flow by adjusting the pressure.