ONLINE SELF-STUDY

Compressed Gas Safety

Objectives

In accordance with OSHA's Hazardous Materials

standard (29 CFR 1910 Subpart H) it is important:

To understand hazards associated with compressed

gases.

To learn how to effectively manage these hazards.

To learn about University policies regarding

compressed gas use.

About Compressed Gases

A compressed gas cylinder is any

cylinder specifically designed to contain

gases under pressure of greater than

one atmosphere, and having the

capability of dispensing the gas by the

means of a control valve mechanism to

assure the safe and proper use of the

gas at a point of operation.

About Compressed Gases

Compressed gases are hazardous

because they can cause fires, explosions,

oxygen deficient atmospheres, and toxic

gas exposures. In addition there are the

innate physical hazards associated with

cylinders under high pressure.

About Compressed Gases

A variety of compressed gases exist,

including flammables, non-flammables,

explosives, corrosives, as well as toxic

and oxidizing gases.

Reference labeling, safety data sheets

(SDS), and other safety literature for

specific hazard information.

About Compressed Gases

Special storage, usage, handling and

disposal procedures are necessary to

ensure the safety of employees using

compressed gases.

Also, compressed gases should be

included in chemical inventories . For

laboratories, their hazards should be

indicated on lab entrance signs.

Labels

All compressed gas cylinders must

bear labels that clearly identify the

contents.

Labels

No compressed gas cylinder should

be accepted that does not have its

contents identified by name.

If labeling on a cylinder is not clear

and the contents cannot be

identified, the cylinder should be

marked "contents unknown" and

returned directly to the

manufacturer.

Labels

Do not use the color of a cylinder

for identification. Color coding may

vary between suppliers. Also, do

not rely on labels on cylinder caps

because these caps are

interchangeable.

Storage

Store cylinders in designated areas where they will not be

knocked over or damaged by passing or falling objects.

Where cylinders are stored in the open, they should be

protected from accumulations of ice and snow and from the

direct rays of the sun. Full cylinders should be used in rotation

as received from the supplier.

Storage

Cylinders should not be subjected to a temperature above

125°F, nor should a flame ever be permitted to come in

contact with any part of a compressed gas cylinder.

Tanks should not be stored in cold rooms due to the lack of

exhaust in these spaces.

Storage

Compressed gas cylinders must be in an

upright position and supported at all times,

whether full or empty.

Be sure to secure the cylinder above its

center of gravity (~2/3 up the cylinder).

Do NOT secure cylinders by the valve.

Do NOT attempt to catch a falling cylinder.

Storage

Acceptable methods of support include:

wall-mounted or bench-mounted gas

cylinder brackets

chains or belts anchored to walls or

benches

dollies or carts designed for gas

cylinders and equipped with safety

chains or belts

Storage

The picture to the right is an example of

how NOT to secure a compressed gas

cylinder. This does not provide sufficient

support.

Securing cylinders individually is ideal. If

cylinders must be ganged together for

storage, only gang two cylinders together

at a time, if possible. If it is necessary to

gang more cylinders together please

contact EHS for advice.

Transporting Cylinders

Valve caps must be securely fastened before

cylinders are moved. Use appropriate dollies or

hand trucks to move cylinders weighing more than

50 pounds. Cylinders should never be rolled or

dragged.

Transporting Cylinders

Improper handling can seriously weaken the cylinder

and render it unfit for further use, or transform it into

a rocket having sufficient thrust to drive it through

walls. (You can watch the MythBusters make this

happen.)

Regulators and Gauges

Pressure regulators and gauges must

be compatible with the cylinder valves.

You may not use "cheaters" (adapters)

instead of the correct regulator and

gauge.

Regulators and Gauges

The Compressed Gas Association has devised standard outlet connections to prevent mixing of incompatible gases. Outlet threads may vary in diameter. Some are internal, some are external; some are right-handed, some are left-handed.

If a valve must be forced, it is a good sign that the wrong valve is being used.

Regulators and Gauges

All the connections should be checked

with a soap solution for leaks (except

for oxygen tanks). Never use oil or

grease.

Threads on cylinder valves, regulators

and other fittings should be inspected

regularly to ensure they are correct

and undamaged.

Regulators and Gauges

Cylinders should be visually inspected to ensure that they are in safe condition. If a leaking cylinder is discovered, move it to a safe place (if it is safe to do so) and contact EHS for precautionary advice and disposal assistance. You should also call the vendor as soon as possible.

Do NOT attempt to repair a cylinder or valve.

Special Notes

Lecture Bottles

Lecture bottles are small compressed

gas cylinders, typically 12-18 inches

long and 2-3 inches in diameter.

Lecture bottles should be secured

during use. All lecture bottles

containing hazardous gases should be

used in a chemical fume hood. These

cylinders are typically non-returnable.

Special Notes

Hydrogen and Acetylene

Hydrogen is a colorless, odorless and

tasteless gas. Acetylene is a colorless

gas with a distinctive garlic-like odor.

These are both flammable gases. A

mixture of either gas with oxygen or air

in a confined area will explode if

ignited by spark, flame or other source

of ignition.

Special Notes

Hydrogen and Acetylene

Post all hydrogen and/or acetylene

storage and usage locations with

permanent placards that read:

HYDROGEN/ACETYLENE

- FLAMMABLE GAS -

- NO SMOKING -

- NO OPEN FLAMES -

Special Notes

Oxygen

Oxygen is a colorless, odorless, and

tasteless gas. It can greatly accelerate

combustion. These cylinders should never

be stored near flammable gases.

Greasy or oily material should never be

stored around oxygen. Also, do not use

soap based leak detector compounds on

the connection threads of an oxygen

cylinder.

Special Notes

Corrosive Gases

Corrosive gases can burn and destroy

body tissues on contact. Corrosive

gases can also attack and corrode

metals. Common corrosive gases

include ammonia, hydrogen chloride,

chlorine and methylamine.

Special Notes

Cryogenic Gases

Cryogenic gases are extremely cold and

accidental contact with eyes or skin may

cause severe frostbite.

Personal protective equipment (PPE) must be

worn by employees who handle and use

cryogenic gas cylinders. This includes gloves

constructed of insulating materials, rubber

aprons, safety glasses or goggles and a

complete face shield.

Special Notes

Cryogenic Gases

Proper PPE:

Special Notes

Cryogenic Gases

Tremendous pressures can result in enclosed

spaces as the liquid converts to gas. For

example, one cubic centimeter of liquid

nitrogen will expand to 700 times this

volume as it converts to its gaseous state.

For this reason, asphyxiation can be an issue.

Depending on the size of a room and volume

of gas, an oxygen monitor may be needed.

Special Notes

Dangerous Gases

Any gases that may cause significant acute health

effects at a low concentration are considered

dangerous gases.

Cylinders of dangerous gases, such as ammonia,

carbonyl sulfide, hydrogen cyanide, hydrogen

sulfide, methylamine, and nitric oxide, must follow

the University's Dangerous Gas Policy.

Disposal

There are two general types of compressed

gas cylinders:

returnable (owned by the gas supplier,

rental fee charged to the University)

non-returnable

Most suppliers will accept the return of their

cylinders even if they are not empty.

However, suppliers will not accept non-

returnable cylinders under any circumstances.

Lecture bottles are typically non-returnable.

Disposal

Disposal of non-returnable cylinders

containing highly toxic or reactive gas can be

very expensive. Therefore, purchase

compressed gases in returnable cylinders if

available. If non-returnable cylinders are the

only alternative, be prepared to pay for the

cost of disposal. To dispose of these cylinders

request a waste pickup online through EHS.

Review

All compressed gas cylinders must bear labels that clearly identify the contents.

Compressed gas cylinders must be in an upright position and supported at all times, whether full or empty. Acceptable methods of support include:

wall-mounted or bench-mounted gas cylinder brackets;

chains or belts anchored to walls or benches; and,

free-standing dollies or carts designed for gas cylinders and equipped with safety chains or belts.

Review

Gas cylinders must have the valve protection

cap in place except when in use.

Use appropriate dollies or hand trucks to move

cylinders weighing more than 50 pounds.

Review

Pressure regulators and gauges must be compatible

with the cylinder valves. You may not use "cheaters"

(adapters) instead of the correct regulator and

gauge.

Reference labeling, safety data sheets (SDS), and

other safety literature for specific hazard

information.