Compressed gas cylinders present a variety of hazards due to their pressure and/or their content. Depending on the particular gas, there is also potential simultaneous exposure to both mechanical and chemical hazards. Compressed gases may be:
- Flammable or Combustible
Compressed gas cylinders have very high internal pressures, in some cases up to 2,500 psi. Exposing these cylinders to heat, knocking them over, or allowing them to become part of an electric circuit can contribute to weakness in the cylinder wall or damage to the valve. Such careless actions or damage can cause:
- The cylinder to tip over onto the user causing a contusion or crushing injury
- The cylinder wall ruptures and explodes, sending metal shrapnel flying into the air
- The valve becomes broken off, rapidly releasing all of the gas contents and possibly spinning out of control or actually becoming airborne
Each compressed gas cylinder has unique hazards based on its contents. An incident involving the release of flammable, corrosive, explosive, toxic, or a combination of these gases could cause harm to human health. Some gases are inert, but do not confuse this with being “safe!” Depending on the gas or mixture of gases, an accidental release or leak from a cylinder could cause:
- Burns or frostbite from contact with rapidly expanding gases
- Suffocation (asphyxiation) or death
- Chemical poisoning from toxic gases
- Damage to certain target organs
- Exacerbation of pre-existing health problems
- An increased risk of fire and may aid combustion
- Destruction of skin and mucous membranes
Storage of Compressed Gas Cylinders
Proper storage of gas cylinders is paramount to the safety and health of anyone using compressed gas cylinders.
Follow these simple guidelines to ensure that cylinders are guarded against damage:
- Store cylinders upright, in well-ventilated areas, and out of inclement weather
- Place cylinders in a location where they will not be subject to damage, heat, or electrical contact
- Do not store cylinders in exits or egress routes, like public hallways or other unprotected areas
- Store gases with the same hazard class in the same area
- Inert gases are compatible with all other gases and may be stored together
- Mark the storage area with proper precautionary signs, such as no smoking, fuel gas storage, or oxidizer storage
- Properly secure tanks to a stable object, using chains, straps, or cages
- Fix or secure tanks at approximately 2/3 the height of the cylinder – secured above the midpoint but below the shoulder
- Cylinders approved stands or wall brackets may ensure less than 18″ tall
- Never store acetylene cylinders on their sides
- Completely close the valves, and keep the valve protection caps on cylinders when not in use or attached to a system
- Keep oxygen cylinders at least 20 ft. away from all flammable, combustible, or incompatible substances
- Store empty cylinders separately from full cylinders
- Ensure that empty tanks are labeled or tagged, indicating that the tank is “empty” and that the valves are closed with the protective cover in place.
Handling & Transport of Gas Cylinders
Most accidents or injuries involving cylinders happen when moving or handling gas cylinders. Use the right equipment, follow the correct procedures and use a sufficient number of personnel to lift or move cylinders to avoid personal injury and cylinder damage.
Handling and Use Requirements:
- Keep cylinders upright and away from heat, sparks, fire, physical damage, or electrical circuits to avoid rupture
- Clean valves of any dust or dirt before attaching the regulator, and always use the correct regulator for the specific gas intended
- Never force connection fittings and do not tamper or alter the regulators
- Stand off to the side of the cylinder when opening a valve
- Inspect the regulator and cylinder valves for grease, oil, dirt, and solvent
- Never use grease or oil to lubricate regulators or cylinder valves because they can cause an explosion
- Position the cylinder so that the valve handle at the top is easily accessible
- When using toxic or irritating gas, the valve should only be opened while the cylinder is in a working fume hood
- Always open valves slowly and only use wrenches or tools that are provided by the cylinder supplier
- Never use screwdrivers or pliers to open a cylinder valve
- Use in a well-ventilated area to avoid gas accumulation
- Do not bring cylinders into a confined space
- Never use copper fittings or tubing on acetylene tanks – an explosion may result
- Close the cylinder valve and release all pressure before removing the regulator from the cylinder
- Never leave pressure in a regulator when it is not in use
- If you suspect that a cylinder is leaking, use soapy water
- Never use a flame to detect a gas leak
OSHA Standard Interpretations – Cart Storage:
OSHA has issued several Standard Interpretations stating that failure to comply with the storage requirements under either the General Industry or Construction Standard would be considered de minimis (no penalty and generally no citation) regardless of the period of time in which the cylinders are on the cart if the following parameters are met:
1. No more than a single acetylene cylinder and a single oxygen cylinder are on a cylinder cart. The cylinder cart must be specifically designed to hold/carry oxygen and acetylene cylinders in the upright position. The cylinders must be securely stored in the cart (such as by straps, chains, or other securing devices).
2. The cart is on a firm, level surface.
3. The cart is not in an area where there is a reasonably foreseeable risk of being struck by vehicles, equipment, or materials (such as in a pathway for vehicles on a construction site).
4. Both cylinders have valves closed with protection caps on or connected to a properly functioning regulator.