Despite their increasingly widespread use, compressed gases can be dangerous. Working with these gases exposes handlers to both chemical and physical hazards. The gases contained inside the cylinders can be toxic, flammable, oxidizing, or corrosive. Since they are pressurized, they quickly contaminate large areas if the cylinder, the regulator, or any part of the system springs a leak. This means that as a handler, you need to be familiar with the chemical hazards of the gas you are working with. In addition to the chemical hazards, there are hazards that result from the pressure of the gas and the physical weight of the cylinder.
All cylinders containing a compressed gas must be appropriately labeled. The label must include the type of gas and the hazards associated with its use. Never attempt to use a cylinder without a label.
Cylinders also have several stamped markings. The top mark is either a DOT or an ICC marking, which alerts you to the regulations for its handling. The DOT abbreviation refers to the U.S. Department of Transportation and the ICC marking refers to the International Code Council, which is a membership association dedicated to building safety and fire prevention. The second mark is the serial number. Under the serial number is the symbol of the manufacturer, user, or purchaser. The label must also contain the date it was manufactured and the month and year of the retest date. An A (+) sign indicates the cylinder may be 10% overcharged, and a star indicates a ten-year test interval.
Before you begin working with a cylinder, you need to be sure that all connections are tight. Use soapy water to check for leaks. You should also check that valves, regulators, couplings, and hoses are clean and free of any oil or grease. These components need to be kept oil and grease free the entire time you are using a compressed gas cylinder.
The cylinder valve should always be opened slowly. Stand away from the face and back of the gauge when opening. If a special wrench is necessary to open a cylinder or manifold valve, the wrench should be left in place on the valve stem while the cylinder is in use. This will enable you to shut off the gas supply quickly in case of an emergency. It also ensures that nothing will be placed on top of a cylinder that may damage the safety device or interfere with an emergency closing.
Keep cylinders away from open flames and other sources of heat at all times. A fire-extinguishing apparatus should be readily accessible when combustible materials are exposed to welding or cutting that necessitates the use of compressed cylinder gases. Use flashback arrestors and reverse-flow check valves to prevent flashback when using oxy-fuel systems.
Never tamper with safety devices and valves. Likewise, you should never attempt to repair a damaged or broken valve. Remove all regulators when work is completed, when moving the cylinders, and when cylinders are empty.
If you must transport a compressed gas cylinder, use a cylinder cart and secure the cylinders with a chain. Don’t try to move or lift cylinders by pulling on the protective valve caps. Don’t drop a cylinder; it can explode on impact. The physical weight can crush your toes if you are not wearing steel-toed shoes. You should also never handle cylinders roughly or allow them to crash into each other. Unless cylinders are secured on a cart, regulators should be removed, the valves should be closed and the protective valve caps should be in place before the cylinders are moved.
Finally, always have the correct Material Safety Data Sheet available for the gas contained within the cylinder(s) you are working with. Be sure you are familiar with the health, flammability and reactivity hazards associated with those gases. Don’t wait until an emergency to try to find the information you will need to handle the situation. Contact us for more resources and information.