Compressed Gas Safety for Laboratories

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Compressed Gas Safety for Laboratories

• Discussion topics
• Potential hazards
• Safety considerations regarding
• Selecting/ Receiving gases
• Handling cylinders
• Use Storage
• Research Experiments Systems
• Emergency procedures

Stanford University Environmental Health
Safety Occupational Health Safety Program,
725-3209, lsteng_at_stanford.edu Stanford Fire
Marshals Office 723-0609, jleung_at_stanford.edu Co
nmpressedgas.Rev.9-2000.ppt IH Report 98-080 /
SUFMO 02-00
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Additional Training Will Be Required
This training provides information about safe
handling, storage and general hazards of
compressed gases. It does not provide specific
detailed training necessary to safely install or
use compressed gases. Prior to actual use of any
compressed gases your supervisor will need to
provide operation specific training in this area.

• If you dont understand ask questions!
• If you forget ask questions!
• If it doesnt seem right ask questions!
• We would rather answer questions than deal with a
  accident

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Regulations for Compressed Gas Use Storage

• Compressed gas use storage are regulated by
  different organizations.
• California Fire Code
• Occupational Safety Health Administration
  (CalOSHA)
• Santa Clara County Environmental Health
  Department

4
Characteristics of Gases

• Gases are much lighter than liquids solids.
• The molecules of a gas are always in motion.
• Escaped gases will eventually distribute
  themselves throughout the air in a room or other
  confined space.
• Some gases have odors, some do not.
• Most gases are invisible, some can be seen.
• All gases have some property that can be
  hazardous to you.

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Types of Gases

• Non-liquefied Compressed Gases Nitrogen, Argon,
  Helium, Oxygen, Hydrogen
• Liquefied Compressed Gases-Chlorine, Hydrogen
  chloride, Carbon Dioxide, Nitrous Oxide,
  Dichlorosilane, Hydrogen Bromide
• Compressed Gases in a Solution-Acetylene
• Cryogenic Liquefied Gases-Nitrogen, Argon,
  Helium, Oxygen, Hydrogen

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Potential Hazards

• High Pressure
• Asphyxiation
• Flammability
• Explosion
• Toxicity
• Corrosion
• Oxidation
• Pyrophoric
• Cryogenic

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Purchasing/ Receiving Gases

• REDUCE YOUR RISKS!
• Select the lowest concentration of hazardous gas
  that will allow you to perform your experiment.
• Purchase the smallest quantities to satisfy your
  research needs.
• Select only gases that are delivered in
  returnable containers
• When receiving gas cylinders
• Check for leaks
• Visually inspect for damage
• Ensure valve cover and shipping cap are properly
  in place.
• Check that cylinder is properly labeled

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Cylinder Story
Cylinders come in different sizes, shapes and
colors
Remember the gas supplier must label the cylinder
with the contents Check the label before you
accept, move or use the cylinder.
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Safe Handling of Gas Cylinders

• Before handling, make sure that valve cap is
  secured
• Transport gas cylinders using only a suitable
  cart
• Always take the safest most direct route when
• transporting gas cylinders
• Never leave un-restrained cylinders un-attended

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Safe Storage of Compressed Gas Cylinders

• Only store cylinders in authorized locations.
• Separation of incompatibles (check SU storage
  group information)
• Restricted access to compressed gas cylinder
  storage.
• Store away from main building access/ egress
  points

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Safe Storage of Compressed Gases

• Attach valve cap when a gas cylinder is not in
  service
• Cylinders must be stored upright
• Metal restraints at 1/3 AND 2/3 height of
  cylinder
• Max of 2 gas cylinders per set of chains

• Cylinder bench clamps
• are NOT allowed

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Safe Use of Compressed Gases

• DO NOT tamper with the stem and cylinder valves
• NEVER use damaged regulators, connectors, piping,
  etc.
• For cylinders in use, cylinder valves must have
  hand wheel attached
• Close cylinder valve whenever
• work is finished
• cylinder is empty
• Label empty cylinders
• Ensure safe proper exhaust for purging
  pressure relief for toxic, flammable, or
  corrosive gases

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Additional Precautions
Some gases require special permits and controls
for use. These are toxic, corrosive, flammable
and pyrophoric gases. Check with SU EHS during
the design of the experiment in order
to understand the permitting and engineering
control requirements.
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Research Experiments and Systems

• Label all gas lines
• Remember to check safety devices (check valves,
  flow restrictors, pressure gauges, regulators)
• Select proper construction materials
• Leak test system before start-up at cylinder
  changes
• Check for proper exhaust ventilation for the lab
  and apparatus prior to opening gas cylinders

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Emergency Procedures

• Standard Operating Procedures (SOP)
• Bottom line.Not only are they a good idea, they
  are required!
• BE PREPARED!
• Know your emergency procedures
• Know your emergency contacts
• Know what to do if the unexpected happens

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For More Information

• EHS Compressed Gas training
• Guide to Safe Handling of Compressed Gases,
  Matheson
• Handbook of Compressed Gases, Compressed Gas
  Association
• Gas Data Book, Matheson

• Occupational Health Safety Program- EHS
• Ling Sue Teng, 725-3209, lsteng_at_stanford.eud
• Stanford Fire Marshals Office- EHS
• Joseph Leung, 723-0609, jleung_at_Stanford.EDU