Compressed Gas Factoids
To recap and round out the last couple of articles about the safe handling of compressed gasses, here are a few “must know” info bits to incorporate into training classes or toolbox talks. Compressed gases present many serious hazards from asphyxiation to explosion and fire. Here is some advice for making sure your workers know how to identify hazards for the gases used in their work area and understand the consequences for lapses in handling procedures.
Common gases and their hazards:
Acetylene is very flammable and explosive, and its safe maximum pressure is just 15 pounds per square inch for small-diameter piping systems.
Ammonia is flammable, but also poses a danger of freeze burns, severe eye injury, and respiratory injury. Inhaling high concentrations of ammonia can kill you, so respirators, eye and face protectors, and impervious protective clothing are musts when working with this gas.
Carbon dioxide can, in high concentrations, be toxic. It can also asphyxiate you. Although it will smother fires of petroleum, coal, and wood, carbon dioxide burns rapidly with other substances such as magnesium, sodium, potassium, and metal hydrides.
Chlorine can explode in reactions with alcohols, ethers, and petroleum products. If you mix it with acetylene, it will explode when exposed to sunlight. If you mix it with water, it will eat into iron and steel.
Fluorine is both corrosive and poisonous and attacks most materials. If you mix it with acetylene, it may explode when exposed to light.
Hydrogen is extremely flammable and explosive. It requires good ventilation, particularly in storage.
Oxygen doesn’t burn by itself, but flammable materials burn much faster in it. It can produce spontaneous ignition when combined with other elements and compounds.
OSHA regulations specify how to work safely with compressed gas cylinders. Workers need to know the safety precautions for identifying, storing, and moving cylinders.
- Each cylinder should be marked with its identity, so you know which material safety data sheet (MSDS) to check to find out about hazards and protections. Empty cylinders have to be identified, too, with the letters “MT” or just simply “Empty”.
- Compressed gases must be stored in a dry, well-ventilated area at least 20 feet from combustible materials, and away from any heat source or electrical wiring.
- Keep cylinders away from stairs and elevators. They should be stored on a level, fireproof floor in a place where they won’t be banged or knocked over. Secure them in an upright position by chain, cable, or something similar.
- Oxygen cylinders also have to be stored at least 20 feet from combustible materials or full gas cylinders. When cylinders are in storage, valves have to be closed and valve protection caps should be screwed down to the last thread.
- Storage areas need to be organized so that workers always go for the cylinders that have been there the longest. Put the newest ones received in the back.
- The safest way to move gas cylinders is to secure them upright to a hand truck. Be careful that they don’t drop or get banged or bumped.
This is NOT how its done:
General Use Precautions
When using compressed gases, workers need to follow several precautions. General precautions are listed below. Train your workers on these, plus any specific precautions for the gases they use.
- Keep cylinders away from operations that create sparks, heat, and fire, as well as electrical circuits.
- Don’t use oil or grease on cylinders or handle them with oily hands or gloves.
- Don’t let oxygen spray on an oily or greasy surface or on your clothes.
- Don’t use cylinders in unventilated areas.
- Open valves by hand, not with a wrench or other tool. If they don’t open, notify the supplier.
- Don’t tamper with safety devices.
And finally, seeing is believing, as they say:
- The Sleeping Giant – Compressed Gas in the Workplace (safetygator.wordpress.com)
- Essential Training: Compressed Gases (safetygator.wordpress.com)
- Blaze, explosions destroy house (stuff.co.nz)
- Gas cylinder blast causes panic near Tripoli school (dailystar.com.lb)
- CSB Safety Video: Dangers of Propylene Cylinders