Safetygram-1 Gaseous Oxygen
This crude oxygen liquid is withdrawn fromthe column and sent to a low-pressure
column where it is distilled until it meets
commercial specifications. The liquid oxygen
is sent to a cryogenic storage tank.
odorless, tasteless, and nonflammable. Oxygen is necessary to support life. It is a
strong oxidizer that combines readily with
contain some of the same unit processes such
as compression and clean-up, but differ in the
fundamental technology to separate air into itscomponents. Oxygen can be separated from
Oxygen will react with nearly all organic
materials and metals. Materials that burn
Adsorption (PSA/VSA) technology. Adsorption
easily in air will burn more vigorously in
relies on a material (zeolite) that has the
property of selectively adsorbing nitrogen while
must meet stringent cleaning requirements;
under a slight pressure and allowing oxygen to
any system must be constructed of materials
that have high ignition temperatures and which
released from the zeolite by dropping the
are nonreactive with oxygen under the service
pressure to a lower level (often under vacuum)
conditions. Vessels should be manufactured to
during the PSA/VSA process. When oxygen is
produced by adsorption, argon flows through
(ASME) codes and designed to withstand the
with the oxygen, producing oxygen with a
temperatures and pressures involved. Manufacture
Oxygen is produced by an air separation unit
Oxygen is generally liquefied so it can be
(ASU) through the liquefaction of atmospheric
more effectively transported and stored in
air and separation of the oxygen by continu-
large volumes. However, most applications
ous cryogenic distillation. The oxygen is then
use oxygen in the gaseous form. The primary
removed and stored as a cryogenic liquid.
uses of oxygen relate to its strong oxidizing
and life-sustaining properties. Oxygen is
cally using selective adsorption processes to
commonly relied upon in health and medical
applications. Liquid oxygen is used as an
The ASU manufacturing process begins with a
oxidant for liquid fuels in the propellant
main air compressor and ends at the output of
the product storage tanks. Air is compressedand sent through a clean-up system wheremoisture, carbon dioxide, and hydrocarbons are removed. The air then passes through heat exchangers where it is cooled to cryogenictemperature. Next, the air enters a high pressure distillation column where it is physi-cally separated into a vaporous form of nitrogenat the top of the column and a liquid form of“crude” oxygen (~90% O2) at the bottom. Responsible Care® A Public Commitment
Oxygen is widely applied in the metal indus-
Table 1: Gaseous Oxygen Physical and Chemical Properties
tries in conjunction with acetylene and otherfuel gases for metal cutting, welding, scarfing,
Chemical Formula x
hardening, cleaning, and melting. Steel and
Molecular Weight x
iron manufacturers also extensively use oxygen
Boiling Point @ 1 atm x
or oxygen-enriched air to affect chemical
Freezing Point @ 1 atm x
refining and heating associated with carbon
Critical Temperature x
removal and other oxidation reactions. Benefits
Critical Pressure
such as fuel and energy savings plus lower
total emission volumes are realized when air is
Density, Liquid, @ BP, 1 atm x
enriched or replaced with higher-purity oxygen. Density, Gas @ 68°F (20°C), 1 atm x
In the chemical and petroleum industries,
Specific Gravity, Gas (air=1) @ 68°F (20°C), 1 atm x
oxygen is used as a feed component to react
Specific Volume @ 68°F (20°C), 1 atm x
with hydrocarbon building blocks to produce
Latent Heat of Vaporization x Expansion Ratio, Liquid to Gas, BP to 68°F (20°C) x
that contain oxygen in their structure. In many
Solubility in Water @ 77°F (25°C), 1 atm x
processes, the oxygen for reaction can beobtained from the use of air. However, directuse of oxygen, or enrichment of the air with
Health Effects
preceded by visual disturbances, such as loss
oxygen, is necessary for some processes.
of peripheral vision, also occur. Continued
There are several major petrochemical inter-
exposure can cause severe convulsions that
oxygen is essentially nontoxic. No health
can lead to death. The effects are reversible
with high-purity oxygen including ethylene
and propylene oxide (antifreeze), vinyl chloride
exposed to concentrations up to 50% at 1atmosphere for 24 hours or longer.
Premature infants placed in incubators to
(for PVC), and caprolactam (for nylon).
breathe oxygen in concentrations greater than
The pulp and paper industry uses oxygen as
in air can develop irreversible eye damage.
a bleaching and oxidizing agent. A variety of
Within six hours after an infant is placed in a
irritation of the respiratory tract, progressive
high-oxygen atmosphere, vasoconstriction of
physical properties after treatment with
decrease in vital capacity, coughing, nasal
the immature vessels of the retina occurs,
oxygen; plant operating costs also improve.
which is reversible if the child is immediately
followed by tracheobronchitis and later by
Similarly, oxygen enhances the combustion
returned to air but irreversible if oxygen-rich
process in industries that manufacture glass,
therapy is continued. Fully developed blood
aluminum, copper, gold, lead, and cement
vessels are not sensitive to oxygen toxicity.
or that are involved in waste incineration or
irritation and edema after 24 hours. Containers
Respiratory symptoms can occur in two to six
emissions benefits end-users may realize.
hours at pressures above 1 atmosphere. One
high-pressure cylinders, tubes, or tube trailers
of the earliest responses of the lung is accu-
depending on the quantity required by the
mulation of water in the interstitial spaces and
user. Cylinders are designed and manufac-
process efficiency. Aquaculturists such as
within the pulmonary cells. This can cause
fish-farmers also see benefits in the health
reduced lung function, which is the earliest
specifications for the pressures and tempera-
or size of their livestock when the host
measurable sign of toxicity. Other symptoms
tures involved. Cylinders are manufactured
include fever, and sinus and eye irritation.
according to Department of Transportation
(DOT) regulations, which specify the material
greater than 2 or 3 atmospheres, a character-
of construction, method of manufacture, test-
istic neurological syndrome can be observed.
ing, and what products they are permitted to
Signs and symptoms include nausea, dizzi-
be filled, as well as other details. The quantity
ness, vomiting, tiredness, light-headedness,
of product a container can hold is determined
mood changes, euphoria, confusion, incoordi-
by its pressure rating and internal volume.
nation, muscular twitching, burning/tingling
Generally the higher the pressure, the more
sensations particularly of the fingers and toes,
and loss of consciousness. Characteristicepileptic-like convulsions, which may be
1. Cylinder Specification 5. Neck Ring Identification
• DOT–Department of Transportation, which
• The cylinder neck ring displays the name of
Fig. 1 Typical cylinder shapes and sizes.
is the regulatory body that governs the use
6. Retest Markings Cylinders
• Specification of the cylinder type of material of
Month–Facility–Year–Plus Rating–Star Stamp.
A cylinder is a hollow tube with a closed
• Service or working pressure in pounds per
• The + symbol (Plus Rating) indicates that the
concave base that permits it to stand upright.
cylinder qualifies for 10% overfill. 2. Cylinder Serial Number
• The ★ symbol (Star Stamp) indicates that the
• The letters SG precede the serial numbers for
cylinder meets the requirements for 10-year
the installation of a valve. A threaded neck
3. Registered Owner Symbol 7. CylinderTrak™ Bar Code Label
ring is attached to the tapered end so that a
• Symbol used to indicate the original owner of
• The CylinderTrak bar code label provides a unique
protective cylinder cap can be installed.
cylinder identifier and is used by computer sys-
• APROINC is a Registered Owner Symbol for
tems to track cylinders throughout the fill process.
As an optional service, we have the capability of
groups. When used in groups, the cylinders
4. Date of Manufacture
tracking cylinders to and from customers.
should be piped together, for either stationary
• This date (month-year) also indicates the
8. Cylinder Manufacturer’s Inspection Marking 9. Cylinder Tare (Empty) Weight
A tube is a pipe tapered at both ends. Each
Valve Connections Pressure-Relief Devices
end is threaded to allow the installation ofvalves, connections, or relief devices.
Oxygen containers are equipped with pressure-
relief devices to protect from overpressuriza-
tion and possible rupture. Cylinders less than
65” long use a rupture disk device. Cylinders
over 65” use a combination device consisting
used for transportation or mounted perma-
In addition, a high-integrity connection also
of a rupture disk backed by a fusible alloy.
nently at a site. Tubes are generally mounted
Combination devices require that both the
on a truck-trailer chassis or railcar bed, or
placed at stationary locations when large
oxygen service; medical post-type valves are
reached before the device will relieve. For more
information on pressure-relief devices consult
for details. For detailed drawings of these
Air Products’ Safetygram-15, “Cylinder
connections consult CGA Pamphlet V-1. For
general drawings consult the Air Products“Specialty Gases and Equipment Catalog.”
Container Stampings WARNING: NEVER use adapters to make
Each cylinder or tube is identified by stamp-
cylinder connections!!!
ings in the metal of the shoulder. Fig. 3depicts an example of these stampings and
Table 2: Oxygen Service Connections Cylinder Service CGA Connection
Fig. 2 A typical tube container system for gaseous
Shipment of Gaseous Oxygen Safety Considerations
• Cylinders should be stored upright in a
comply with DOT regulations. This applies
with gaseous oxygen. Although nonflammable,
well-ventilated, dry, cool, and preferably
to motor freight, rail, air, and water ship-
• Storage temperatures should NEVER
Transport Association / International Civil Air
exceed 125°F (52°C) and the area should
It is important to note that fire chemistry
be free of combustible materials. Storage
International Maritime Organization (IMO)
regulations. All packaging used to transport
• Oxygen must be separated from flammables
and combustibles by 20 feet or a half-hour
containing at least 23% oxygen. Materials
Specification” or “UN/DOT Authorized” and
easily ignited in air not only become more
in proper condition for transport. DOT Code
susceptible to ignition, but also burn with
• Post “No Smoking” and “No Open
of Federal Regulations, Title 49, also speci-
fies the following labeling and identification
that readily trap oxygen. Oxygen levels of
DOT Shipping Name: Oxygen, Compressed
www.airproducts.com/productstewardship. DOT Hazard Class: 2.2
personnel must be aware of the hazard.
• Avoid areas where salt or other corrosive
DOT Shipping Label: Nonflammable Gas and
Oxidizer (For domestic shipments only the
stringent cleaning requirements to eliminate
caps and valve outlet seals should remain
Identification Number: UN1072
Pamphlet G-4.1, “Cleaning Equipment for
• Separate full from empty cylinders. Avoid
Oxygen Service,” describes cleaning meth-
and CGA Pamphlet O2-DIR, “Directory ofCleaning Agents for Oxygen Service,” pro-
• Use a first-in first-out (FIFO) system.
vides comparative information on cleaningagents used to clean oxygen equipment. Handling
Also, review the appropriate Material Safety
• Use only oxygen compatible lubricants.
• If you experience any difficulty operating
Buildings
the container valve or with the container
the supplier. Use the proper connections.
• DO NOT USE ADAPTERS!
them clear of combustible materials andpost signs indicating the hazard. Also post
“No Smoking” signs. Test the atmospheres
in confined work areas for oxygen content.
withstand pressures to be encountered.
cause materials that burn in air to burnmore violently or even explosively. Oxygen
• It is recommended that all vents be piped
the hazard exposure to personnel and material. Remember, oxygen has no warning properties!
• Use a suitable handtruck designed for
First Aid
• Never attempt to lift a cylinder by its cap.
medical advice for proper health instructions.
• Secure cylinders at all times while in use. Fighting Fires
• Use a pressure reducing regulator or
separate control valve to safely discharge
Since oxygen is nonflammable, but supports
combustion, fire-fighting actions requireshutting off the source of oxygen, if possible,
• Use a check valve to prevent reverse flow
then fighting the fire according to the materi-
al involved. Most cylinders are designed to
• Do not overheat cylinder to increase
• NEVER insert an object (e.g., wrench,
intense heat or flame, a cylinder may vent
screwdriver, pry bar, etc.) into valve cap
openings. Doing so may damage the valvecausing it to leak.
• Use a special cap wrench or adjustable
strap-wrench to remove overtightened or rusted caps. Refilling or shipping compressed gas cylinders without the consent of the owner is a violation of Federal law. Personal Protective Equipment (PPE)
Personnel must be thoroughly familiar with properties and safety considerationsbefore being allowed to handle oxygen and its associated equipment. Safety glasses, safety shoes, and leather workgloves are recommended when handling cylinders.
Only trained and certified emergencyresponders should respond to emergencysituations. In emergency situations, self-contained breathing apparatus (SCBA) mustbe used. Clothing which is fire-resistant inair may be readily ignitable in oxygen-enriched atmospheres. Emergency Response System Product Safety Information
• Call: +1 (800) 523-9374 (Continental U.S. www.airproducts.com/productstewardship
• Call: +1 (610) 481-7711 (Other locations)
Call: +1 (800) 245-2746
• For assistance involving Air Products and
• Enter MSDS Index No. 1000 for a complete
Chemicals, Inc. gases and equipment.
list of available safety literature. Technical Information Center Information Sources
• Call: +1 (800) 752-1597 (U.S.)
• Call: +1 (610) 481-8565 (Other locations)
• Fax: +1 (610) 481-8690
• E-mail: [email protected]
• Monday–Friday, 8:00 a.m.–5:00 p.m. EST
1 Batterymarch Park, P.O. Box 9101Quincy, MA 02269-9101Phone: +1 (800) 344-3555
Air Products and Chemicals, Inc., 7201 Hamilton Boulevard, Allentown, PA 18195-1501Phone: +1 (800) 654-4567, +1 (610) 481-4911. Fax: +1 (800) 880-5204. www.airproducts.com
Printed in USA 310-824 (Rev. 1/00)FOD Index No. 1113
Objectives for Training in Cardiac Electrophysiology Cardiology Training Program University of Calgary Medical Expert At the completion of the rotation the resident will: 1. be able to describe the phases of the cardiac action potential and the ionic currents that contribute to the cardiac action potential 2. be able to describe the anatomy and physiology of the components o
Biochemical and Biophysical Research Communications 291, 1089 –1094 (2002) doi:10.1006/bbrc.2002.6541, available online at http://www.idealibrary.com onReduction of Toxic Metabolite Formationof AcetaminophenEszter Hazai, La´szlo´ Vereczkey, and Katalin Monostory1 Chemical Research Center, Hungarian Academy of Sciences, P.O. Box 17, H-1525 Budapest, Hungary diphosphoglucuronic acid an