STORAGE AND USE OF COMPRESSED GAS CYLINDERS
Compressed gas cylinders are found in many of the laboratories and shops throughout the University. Their storage and use pose a serious potential hazard for all employees and students who may be in the vicinity of or who may handle gas cylinders.
- Supervisor's Responsibility: It is the responsibility of supervisory personnel where gas cylinders are used to see that the following safety rules are observed. They are also responsible to see that all employees and students under their supervision who use gas cylinders have been trained in the safe methods for storage, handling and use of compressed gas cylinders.
- Federal and State Codes and Regulations: Sections 4.4, 4.5 and 4.6 of this chapter deal with rules based on current OSHA and Division of Safety regulations and NFPA codes. They are practical and essential if compressed gases are to be used safely.
4.1. Handling and Use of Compressed Gas Cylinders:
- All compressed gas cylinders (regardless of size) shall be secured to racks, walls, work benches or hand trucks by a strong chain or strap, or secured by any other approved method capable of preventing the cylinder from falling or being knocked over.
- All questionable gas cylinders or equipment shall be reported immediately to the supplier for correction or replacement.
- All cylinders shall be clearly labeled to identify the contents.
- Only personnel trained in the proper transportation and safe use of gas cylinders should handle cylinders.
- Compressed gases shall be used only in areas with adequate ventilation for the gas being used.
- Cylinders shall not be intentionally dropped, struck or permitted to violently strike each other and shall be reasonably protected from violent impact of any kind.
- All cylinders shall be kept far enough away or shielded while in the work area in order to prevent contact with sparks, flame or radiant heat.
- Valve protection caps are required on all cylinders that are threaded to accommodate a cap unless the cylinder valve is actually connected to a regulator or manifold.
- All gas cylinders shall be equipped with a functioning gas regulator while in use.
- No one shall attempt to connect a regulator or accessory equipment by the use of improvised hookups or adapters.
- When personnel have finished using a compressed gas cylinder for the day, the cylinder valve shall be closed and the pressure in the regulator and associated equipment released.
- If a compressed gas is used to maintain a static pressure on a closed system, a clearly visible warning sign shall be posted indicating the approximate pressure the system is under and the gas involved.
- All empty cylinders shall have their valves closed.
- All empty cylinders shall be handled with the same care as full cylinder.
- Compressed gas or compressed air shall not be used for cleaning purposes (to blow dust and debris away) without appropriate reduction valves ( 30 psi. maximum).
- Under no conditions shall high-pressure gas be directed at another person.
- While in use, all cylinders of flammable gases shall be protected by an approved flashback protection device.
- Cylinders of flammable gas shall not be opened more than 1-1/2 turns of the cylinder valve to allow for quick closing. If a special wrench is required, the wrench shall be left in position on the stem of the valve while the cylinder is in use. This allows the gas flow to be shut off quickly in case of an emergency.
- All oxygen, hydrogen and nitrous oxide cylinders and manifolds shall be at least 20' away from or separated by a one-hour rated fire resistant partition from all flammable gases and materials (such as oil, grease, and all petroleum products in general) in the area of use.
- All manifold enclosures for oxygen, hydrogen and nitrous oxide in excess of 2000 cu. feet of manifold capacity shall be vented to the outside and the cylinder or manifold shall be protected with check valves or alarms.
- Due to the possibility of an explosion, all regulators and other equipment used for oxygen shall be identified as being "OXYGEN ONLY" and the equipment used for other gases shall not be used for oxygen.
- Due to the possibility of an explosion, all oxygen regulators, tubing, etc., shall be kept clean and free of all organic materials such as oil and lint.
- In the event a particularly hazardous gas (e.g., phosgene, hydrogen chloride, hydrogen cyanide) is used, a procedure shall be established for evacuating, sealing and isolating the area of use. EH&S shall be notified prior to procuring such hazardous gases.
- Only personnel properly instructed in the chemical hazards of a corrosive or toxic gas are to release or use the gas or operate any equipment using the particular gas.
- All supervisory personnel are to have available the necessary emergency treatment and first aid supplies and be able to administer the necessary first aid that may be required as a result of any hazardous gas being used.
4.2. Transportation of Compressed Gas Cylinders:
- Only personnel of sufficient physical strength should move gas cylinders so as to minimize injury any potential hazard resulting from the size and weight of the cylinders.
- When cylinders are moved, they shall be disconnected from any regulators or manifolds and where threaded to accept protective valve caps, the valve caps shall be secured in place before the cylinders are released from their securing device.
- Cylinders shall be moved only on a hand truck or other cart designed for handling gas cylinders.
- No more than one cylinder shall be handled at a time except on carts designed to transport more than one cylinder.
4.3. Storage of Compressed Gas Cylinders:
- Compressed gas cylinder storage areas must be in a fire resistant enclosure located away from emergency exits and must be kept well-drained, well-ventilated, cool and protected from the weather. Regardless of size, all cylinders shall be provided with supports (straps, chains or other similar devices) capable of preventing the cylinders from falling.
- Under no condition shall the temperature of gas cylinders exceed 50 degrees C (125 degrees F). When Type E gas cylinders are used, they shall not exceed 34 degrees C (93 degrees F) since the relief valves of Type E cylinders are set to release above 35 degrees C.
- Excessive storage time shall be prevented by the use of the smallest practical size cylinder for a particular gas application.
- Corrosive gases shall not be stored for more than six (6) months. Usually after this period of time, there is a deterioration of the gas purity which increases the possibility of cylinder valve malfunction.
- Oxygen, hydrogen or nitrous oxide shall not be stored in the same area with flammable gases unless separated by at least 20' or by a one-hour rated fire resistant partition. Cylinders stored in an area outside a building must be a minimum distance of 20' from flammable gases or combustible material.
- All storage rooms that contain in excess of 2000 cu. feet of oxygen, hydrogen or nitrous oxide shall be vented to the outside.