The document discusses the specifications and safety measures related to medical gas cylinders, including their construction, testing, labeling, and color-coding. It outlines the types of gases, their uses in medical settings, and emphasizes the importance of safety systems like the pin index system to prevent incorrect connections. Additionally, it details the properties and applications of gases such as oxygen, nitrous oxide, carbon dioxide, and helium in medical practices.

1. Cylinders and their Color-
coding System
Ahmad Ullah

2. CYLINDERS
• Cylinders are made of thin-walled molybdenum steel to
withstand high pressures, e.g. 13 700 kPa and 4400 kPa
for oxygen and nitrous oxide, respectively. Lightweight
aluminum is also available.
• They are made in different sizes: size E cylinders are used
on the anesthetic machine; size J cylinders are used in
cylinder banks.

3. Oxygen cylinders contain gas whereas nitrous oxide cylinders contain a
mixture of liquid and vapour.
• At a constant temperature, the pressure in a gas cylinder decreases
linearly and proportionally as it empties. This is not true in cylinders
containing liquid/vapour.
• They are colour-coded (shoulder and body). A new colour system is
being introduced with white bodies but different coloured shoulders.

5. • Critical temperature is the temperature above which a
substance cannot be liquefied no matter how much
pressure is applied. The critical temperatures for nitrous
oxide and oxygen are 36.5°C and −118°C, respectively.

6. Different Test Uses for Cylinder
• Cylinders in use are checked and tested by manufacturers at regular intervals,
every 5–10 years. Test details are recorded on the plastic disc between the
valve and the neck of the cylinder. They are also engraved on the cylinder:
• 1. An internal endoscopic examination is carried out.
• 2. Flattening, bend and impact tests are carried out on at least one cylinder in
every 100.
• 3. A pressure test is conducted, whereby the cylinder is subjected to high
pressures of about 22 000 kPa, which is more than 50% above their normal
working pressure.
• 4. A tensile test is carried out on at least one cylinder in every 100, whereby
strips of the cylinder are cut out and subjected to impact, stretching, flattening
and other tests of strength.

7. • The marks engraved on the cylinders are:
• 1. Test pressure.
• 2. Dates of test performed.
• 3. Chemical formula of the cylinder’s content.
• 4. Tare weight (weight of nitrous oxide cylinder when empty).

8. LABELLING OF CYLINDER
The cylinder label includes the following details:
• Name, chemical symbol, pharmaceutical form, specification of the
product,
its license number and the proportion of the constituent gases in a
gas mixture.
• Substance identification number and batch number.
• Hazard warnings and safety instructions.
• Cylinder size code.
• Nominal cylinder volume (liters).
• Maximum cylinder pressure (bars).
• Filling date, shelf life and expiry date.

9. PIN INDEX SAFETY SYSTEM
• The pin index system is a safety mechanism used primarily in the
medical field to prevent the incorrect connection of gas cylinders to
their associated regulators and equipment. It’s particularly crucial in
settings like hospitals where different gases (such as oxygen, nitrous
oxide, and medical air) need to be accurately delivered.
• Pin Configuration: Each gas cylinder has a unique pin configuration on
its valve that corresponds to specific pins on the regulator or
equipment that attaches to it. The pins are placed in different
positions to match with the holes in the valve, ensuring that only the
correct gas can be attached to the appropriate equipment.

10. • Safety: The pin index system prevents errors by physically preventing
the connection of an incorrect gas cylinder to a regulator. For
example, an oxygen cylinder will have a different pin configuration
than a nitrous oxide cylinder. This design helps avoid dangerous mix-
ups, such as connecting a wrong gas to a patient's breathing
apparatus.

13. MEDICAL GASES
It is defined as gases which are manufactured packed and
intended for giving to a patient for diagnosis, therapy and to
produce anesthesia. It is considered as drugs and their use
without medical practitioner is unsafe.

14. MEDICAL GASES
• oxygen
• Carbon dioxide
• Nitrogen
• Helium
• Nitrous oxide
• Nitrous oxide N2O Laughing gas

16. OXYGEN
Within the hospital environment oxygen is usually found in 3 main
areas
• Critical care areas
• Operating theatres
• Most wards, A&E & treatment therapy areas

17. INTRODUCTION
• It is important for all living cells.
• It is necessary for normal metabolism for the production energy.
• Oxygen is combined with hemoglobin converted into oxy
hemoglobin which dissociate and release oxygen to the cell.
• Requirement of oxygen in body is classified into:

18. • Anoxic
• Inadequate supply of oxygen to the tissue
• Anemic
• Inadequate amount of hemoglobin to supply the oxygen to the
tissue. this is due to hemorrhage, carbon monoxide poisoning etc.
• Carbon dioxide has more binding affinity towards
hemoglobin only oxygen administration is not effective for
the condition.
• A carbon dioxide oxygen mixture [hyperbaric oxygen ] is used for this
condition.

19. • Stagnant
• It occurs due to the inadequate general circulation or retardation of local
circulation. Oxygen is not used in this case whereas cardiotonic drugs are
used to speed up the circulation.
• Histotoxic
• It occurs due to interferences of tissue cell oxidation or uncoupling of
oxidative phosphorylation or cyanide poisoning.
• Histotoxic hypoxia refers to a reduction in ATP production by the
mitochondria due to a defect in the cellular usage of oxygen. An
example of histotoxic hypoxia is cyanide poisoning.

20. use of oxygen
• It is used as inhalant in anesthesia post operative condition, burns and wounds.
• Osmotic condition, gaseous poisoning and artificial respiration.
• It is mixed with 5-7% CO2 which is used for stimulating respiratory center.
• The mixture of oxygen and helium 21:79 is used for patients with severe lung
damage.
• LABELLING
• The shoulder of cylinder should be painted white, and the remainder should be
painted black . The cylinder should carry a label stating oxygen along with this,
oxygen or the symbol O2 should be stenciled in paint on the shoulder of the
cylinder.

22. Nitrous Oxide (N2O) All Blue
• Nitrous Oxide is used:
• As an inhalation anesthetic as part of a balanced
maintenance of a General Anesthetic.
• Only medical personnel trained in the
appropriate techniques should administer nitrous oxide

23. Uses of NO2
• In General anesthesia for producing analgesic and anesthetic effect.
• A mixture of 1:1 ratio with oxygen is used for the relief of pain in child birth and
heart attack and Myocardial infarction.
• Calming the excited psychiatry patients.
• To induce anesthesia.
• Nontoxic in nature frequently used in dental practice.
• Quickly absorbed anesthetic.
• labelling
• The cylinder is painted with blue color with the name nitrous oxide and the symbol
N2O or the name should be stenciled in paint on the shoulder of the cylinder.

24. Entonox
• A compressed gas mixture with 50% oxygen and 50% nitrous oxide by
volume at a pressure of 13 700 kPa.
• A two-stage pressure demand regulator is usually used.
• Liquification and separation occurs at temperatures below −5.5°C
(Poynting effect). This can potentially lead to hypoxic mixtures.
Large cylinders are designed to prevent this.

25. CARBON DIOXIDE
• Carbon dioxide is insufflated into the abdominal cavity to distend it to
allow investigation & treatment of intrabdominal disease and for
laparoscopic surgeries.
• Carbon dioxide should only be given under the direct
supervision of a clinician.

26. • Air contains 0.03% v/v of CO2
• Sources Volcanoes
• Dead bodies decay
• Respiration
• Combustion
• Fermentation

27. Uses of C02
• The mixture of 95: 5 [ ratio of CO2: O2 ] is used in the treatment of carbon
monoxide poisoning for increasing the ventilator exchange rate and dissociation
rate of CO from hemoglobin.
• Inhalation of CO2 has been used for Anxietyand relaxation.
• Detoxification of heroin addicts
• Dry ice as temperature of - 80C is used to remove warts.
• 6% carbon dioxide is toxic.
• labelling
• The shoulder of the cylinder should be painted grey and having the name and
symbol of CO2 stenciled with paint on it.

28. Heliox ( 21%O2 /79%He), brown with
white quartering
• Heliox is a mixture of helium and oxygen
and is often used in emergency situations
where upper or lower airways are partially
obstructed, but may also be used within an
Intensive care setting for those patients
receiving both invasive and noninvasive ventilation.
• Heliox should be administered
via appropriate equipment calibrated
for the gas mixture.

29. Helium
• It contains NLT 99% by volume of He
• It is the second highest element in the periodic table. It is used as a
diluent in oxygen administered during mucosal plug obstructions,
laryngeal edema etc.
• The low density of helium helps to reduce the work of
breathing and improves airflow through obstructed
airways.

30. Uses of He
• Helium - oxygen mixture are easier to breathe by patients with
severe lung damage or with obstructions in upper respiratory tract.
• Helium breathing may also influence vocal pattern and vocal pitch.

31. Storage
• It should be stored and supplied in brown colored metal cylinder.
Mixtures of oxygen and helium in the ratio of 20-21 % and 79-80% v/v
re also supplied in cylinders which are painted black on the body and
white and brown batches on the shoulders and neck.

32. Nitrogen
• It is important constituent of animal and plant tissues;
largely present as amino acid and proteins.
• It is used as diluent for pure oxygen
• It is used as an antioxidant.
• The increased concentration of nitrogen in blood leads to narcosis.
• It is obtained by fractional distillation of liquid air