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• Lab Usage/Safety Manual
• ACS Lab Safety 

BU Gas Cylinder Safety

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  I. Background

  Due to the nature of gas cylinders, special storage and handling precautions are necessary. The hazards associated with compressed gases include oxygen displacement, explosion hazards, toxic effect of some gases, as well as the physical hazards of a ruptured cylinder. There are almost 200 different types of materials in gas cylinders including atmospheric gases, fuel gases, refrigerant gases, poison gases and miscellaneous gases. Compressed gases are usually divided into six basic categories, with some gases falling into more than one classification. The categories are as follows:

  • Flammable Gases
  • Oxygen and Oxidizing Gases
  • Acidic and Alkaline Gases
  • Highly Toxic Gases
  • Cryogenic Liquefied Gases
  • Inert Gases

  A sudden release of these gases can cause a cylinder to become a missile-like projectile, destroying everything in its path. Cylinders have been known to penetrate concrete-block walls. To prevent such a dangerous situation, there are several general procedures to follow for safe storage and handling of a compressed gas cylinder:

  II. Identification of Contents of Compressed Gas Cylinders

  • The contents of any compressed gas cylinder should be identified clearly so as to be easily, quickly, and completely determined by any laboratory worker.
  • A durable tag should be provided that identifies the owner and account number.
  • No compressed gas cylinder should be accepted for use that does not identify its contents legibly by name.
  • Color-coding is not a reliable means of identification; cylinder colors vary from supplier to supplier, and labels on caps have no value because many caps are interchangeable.
  • If the labeling on the gas cylinder becomes unclear or defaced so that the contents cannot be identified, the cylinder should be marked "contents unknown" and the manufacturer contacted regarding appropriate procedures.

  III. Transporting gas cylinders

  • Cylinders transported by truck must be fastened securely in an upright position so that they will not fall or strike each other.
  • Cylinders must not be transported without safety caps. A cylinder's cap should be screwed all the way down on the cylinder's neck ring and should fit securely. Do not lift cylinders by the cap. The cap is for valve protection only.
  • Cylinders should not be transported with the regulator attached to the cylinder.
  • Always use a cylinder cart to move compressed gas cylinders. Refrain from sliding, dragging or rolling cylinders on edge.
  • Hand and foot protection are recommended.
  • Up to two cylinders should be handled (moved) at a time.

  IV. Storage of Compressed Gas Cylinders

  • Cylinders should not be allowed to drop nor be struck violently.
  • Cylinders should be properly secured at all times whether attached to a wall, cylinder truck, cylinder rack, or post.
  • Liquefied flammable gas cylinders should be stored in an upright position or such that the pressure relief valve is in direct communication with the vapor space of the cylinder.
  • Caps used for valve protection should be kept on the cylinders at all times except when the cylinder is actually being used.
  • Cylinders should not be used for rolling, supports, or any purpose other than the transportation and supply of gas.
  • Cylinders should be stored in a well-ventilated area away from flames, sparks, or any source of heat or ignition. Keep cylinders away from electrical circuits.
  • Cylinders should not be exposed to an open flame or to any temperature above 125 degrees F.
  • Oxygen cylinders (empty or full) in storage should be separated from fuel-gas cylinders and combustible materials by a minimum distance of 20 feet or by a barrier at least 5 feet high having a fire-resistance rating of at least one-half hour.
  • Flammable gas cylinders should not be stored with oxygen or nitrous oxide cylinders.
  • Full and empty cylinders of all gases should be stored separately and identified by signs to prevent confusion.
  • Cylinders should not be exposed to continuous dampness, stored near salt or other corrosive chemicals or fumes. Corrosion may damage cylinders and cause their valve protection caps to stick.

  V. Use of Compressed Gas Cylinders

  • Know and understand the properties, uses, and safety precautions of the gas before using the cylinder.
  • Always use the proper regulator for the gas in the cylinder. Always check the regulator before attaching it to a cylinder. If the connections do not fit together readily, the wrong regulator is being used.
  • Before attaching cylinders to a connection, be sure that the threads on the cylinder and the connection mate are of a type intended for the gas service.
  • Do not permit oil or grease to come in contact with cylinders or their valves.
  • Wipe the outlet with a clean, dry, lint-free cloth before attaching connections or regulators. The threads and mating surfaces of the regulator and hose connections should be cleaned before the regulator is attached.
  • Attach the regulator securely before opening the valve wide. Always use a cylinder wrench or another tightly fitting wrench to tighten the regulator nut and hose connections.
  • Open cylinder valves SLOWLY. Do not use a wrench to open or close a hand wheel type cylinder valve. If it cannot be operated by hand, the valve should be repaired.
  • Stand to the side of the regulator when opening the cylinder valve.
  • Do not attempt to repair cylinder valves or their relief devices while a cylinder contains gas pressure. Tag leaking cylinders or cylinders with stuck valves and move to a safe, secure location.
  • Close valves on empty cylinders and mark the cylinder "empty" per the hang tag

  VI. Things Not To Do

  • Never roll a cylinder to move it.
  • Never carry a cylinder by the valve.
  • Never leave an open cylinder unattended.
  • Never leave a cylinder unsecured.
  • Never force improper attachments onto the wrong cylinder.
  • Never grease or oil the regulator, valve, or fittings.
  • Never refill a cylinder.
  • Never use a flame to locate gas leaks.
  • Never attempt to mix gases in a cylinder.
  • Never discard pressurized cylinders in the normal trash.

  TOP 3 OSHA CYLINDER VIOLATIONS

  • Unsecured cylinders
  • Cylinders stored without protective caps
  • Non-compatible gases (such as hydrogen and oxygen) stored together

  For additional information refer to NFPA 55 Storage, Use, and Handling of Compressed and Liquefied Gases in Portable Cylinders and NFPA 45 Fire Protection for Laboratories Using Chemicals. OSHA has regulations governing the use of compressed gases. These regulations refer to specific Compressed Gas Association educational materials. The inspection of gas cylinders is discussed in 29 CFR 1910.101, Compressed Gases. DOT has regulations covering the transportation of compressed gases by rail, highway, aircraft, and waterway

  Incompatible Chemical List

  From Prudent Practices for Handling Chemicals in Laboratories

  • Acetic Acid - Chromic acid, nitric acid, hydroxyl compounds, ethylene glycol, perchloric acid, peroxides, permanganates
  • Acetylene - Chlorine, bromine, copper, fluorine, silver, mercury
  • Acetone - Concentrated nitric and sulfuric acid mixtures
  • Alkali and alkaline earth metals (such as powdered aluminum or magnesium, calcium, lithium, sodium, potassium) - Water, carbon tetrachloride or other chlorinated hydrocarbons, carbon dioxide, halogens
  • Ammonia (anhydrous) - Mercury (in manometers, for example), chlorine, calcium hypochlorite, iodine, bromine, hydrofluoric acid (anhydrous)
  • Ammonium nitrate - Acids, powdered metals, flammable liquids, chlorates, nitrites, sulfur, finely divided organic or combustible materials
  • Aniline - Nitric acid, hydrogen peroxide
  • Arsenical materials - Any reducing agent
  • Azides - Acids
  • Bromine - See Chlorine
  • Calcium oxide - Water
  • Carbon (activated) - Calcium hypochlorite, all oxidizing agents
  • Carbon tetrachloride - Sodium
  • Chlorates - Ammonium salts, acids, powdered metals, sulfur, finely divided organic or combustible materials
  • Chromic acid and chromium trioxide - Acetic acid, naphthalene, camphor, glycerol, alcohol, flammable liquids in general
  • Chlorine - Ammonia, acetylene, butadiene, butane, methane, propane (or other petroleum gases), hydrogen, sodium carbide, benzene, finely divided metals, turpentine
  • Chlorine dioxide - Ammonia, methane, phosphine, hydrogen sulfide
  • Copper - Acetylene, hydrogen peroxide
  • Cumene hydroperoxide - Acids (organic and inorganic)
  • Cyanides - Acids
  • Flammable liquids - Ammonium nitrate, chromic acid, hydrogen peroxide, nitric acid, sodium peroxide, halogens
  • Fluorine - Everything
  • Hydrocarbons (such as butane, propane, benzene) - Fluorine, chlorine, bromine, chromic acid, sodium peroxide
  • Hydrocyanic acid - Nitric acid, alkali
  • Hydrofluoric acid (anhydrous) - Ammonia (aqueous or anhydrohydrous)
  • Hydrogen peroxide - Copper, chromium, iron, most metals or their salts, alcohols, acetone, organic materials, aniline, nitromethane, combustible materials
  • Hydrogen sulfide - Fuming nitric acid, oxidizing gases
  • Hypochlorites - Acids, activated carbon
  • Iodine - Acetylene, ammonia (aqueous or anhydrous), hydrogen
  • Mercury - Acetylene, fulminic acid, ammonia
  • Nitrates - Sulfuric acid
  • Nitric acid (concentrated) - Acetic acid, aniline, chromic acid, hydrocyanic acid, hydrogen sulfide, flammable liquids, flammable gases, copper, brass, any heavy metals
  • Nitrites - Acids
  • Nitroparaffins - Inorganic bases, amines
  • Oxalic Acid - Silver, mercury
  • Oxygen - Oils, grease, hydrogen, flammable liquids, solids, or gases
  • Perchloric acid - Acetic anhydride, bismuth and its alloys, alcohol, paper, wood, grease, oils
  • Peroxides, organic - Acids (organic or mineral), avoid friction, store cold
  • Phosphorus (white) - Air, oxygen, alkalis, reducing agents
  • Potassium - Carbon tetrachloride, carbon dioxide, water
  • Potassium chlorate - Sulfuric and other acids
  • Potassium perchlorate (see also chlorates) - Sulfuric and other acids
  • Potassium permanganate - Glycerol, ethylene glycol, benzaldehyde, sulfuric acid
  • Selenides - Reducing agents
  • Silver - Acetylene, oxalic acid, tartartic acid, ammonium compounds, fulminic acid
  • Sodium - Carbon tetrachloride, carbon dioxide, water
  • Sodium nitrite - Ammonium nitrate and other ammonium salts
  • Sodium peroxide - Ethyl or methyl alcohol, glacial acetic acid, acetic anhydride, benzaldehyde, carbon disulfide, glycerin, ethylene glycol, ethyl acetate, methyl acetate, furfural
  • Sulfides - Acids
  • Sulfuric acid - Potassium chlorate, potassium perchlorate, potassium permanganate (similar compounds of light metals such as sodium, lithium)
  • Tellurides - Reducing agents

Simple Chemical Segregation Guidelines

CLASS OF CHEMICALS	RECOMMENDED STORAGE METHOD	EXAMPLES	INCOMPATIBILITIES SEE MSDS IN ALL CASES
Compressed Gases- Flammable	Store in a cool, dry area, away from oxidizing gases. Securely strap or chain cylinders to a wall or bench top.	Methane, acetylene, propane	Oxidizing and toxic compressed gases, oxidizing solids.
Compressed Gases- Oxidizing	Store in a cool, dry area, away from flammable gases and liquids. Securely strap or chain cylinders to a wall or bench.	Oxygen, chlorine, bromine	Flammable gases.
Compressed Gases- Poisonous	Store in a cool, dry area, away from flammable gases and liquids. Securely strap or chain cylinders to a wall or bench.	Carbon monoxide, hydrogen sulphide (H2S)	Flammable and/or oxidizing gases.
Corrosives - Acids	Store in separate acid storage cabinet.	Mineral acids - Hydrochloric acid, sulfuric acid, nitric acid, perchloric acid, chromic acid, chromerge	Flammable liquids, flammable solids, bases, oxidizers.
Corrosives - Bases	Store in separate storage cabinet.	Ammonium hydroxide, sodium hydroxide	Flammable liquids, oxidizers, poisons, and acids.
Shock Sensitive Materials	Store in secure location away from all other chemicals.	Ammonium nitrate, Nitro Urea, Picric Acid (in dry state), Trinitroaniline, Trinitroanisole, Trinitrobenzene, Trinitrobenzenesulfonic acid, Trinitrobenzoic acid, Trinitrochlorobenzene, Trinitrophenol/Picric acid, trinitrotoluene, Urea Nitrate, Zirconium picramate	Flammable liquids, oxidizers, poisons, acids, and bases.
Flammable Liquids	In grounded flammable storage cabinet.	Acetone, benzene, diethyl ether, methanol, ethanol, toluene, glacial acetic acid	Acids, bases, oxidizers, and poisons.
Flammable Solids	Store in a separate dry, cool area away from oxidizers, corrosives, flammable liquids.	Phosphorus	Acids, bases, oxidizers, and poisons.
General Chemicals Non-reactive	Store on general laboratory benches or shelving preferably behind glass doors, or below eye level.	Agar, sodium chloride, sodium bicarbonate, and most non-reactive salts	See MSDS
Oxidizers	Store in a spill tray inside a noncombustible cabinet, separate from flammable and combustible materials.	Sodium hypochlorite, benzoyl peroxide, potassium permanganate, potassium chlorate, potassium dichromate. The following are generally considered oxidizing substances: peroxides, perchlorates, chlorates, nitrates, bromates, superoxides	Separate from reducing agents, flammables and combustibles.
Poisons	Store separately in vented, cool, dry, area, in unbreakable chemically resistant secondary containers.	Cyanides, heavy metals compounds, i.e. cadmium, mercury, osmium	Flammable liquids, acids, bases, and oxidizers.
Water Reactive Chemicals	Store in dry, cool, location, protect from water fire sprinkler.	Sodium metal, potassium metal, lithium metal, lithium aluminum hydride	Separate from all aqueous solutions, and oxidizers.