Nitrous Oxide

NITROUS OXIDE

Source: igasex.net

Nature:

1. A colorless, non-toxic, odorless, oxidizing liquefied gas with a
slightly sweetish taste and odor.

2.In the eighteenth century, nitrous oxide was known as “Laughing
gas”

3.Nitrous oxide was also known to have an anaesthetic effect.
Toxicity:

Simple asphyxiant and anesthetic. Contact with liquid can cause
cryogenic burns.
Fire Potential:

Mild oxidizer; supports combustion.
Compatible Materials:

Noncorrosive; most common structural materials can be used. Some
plastic materials may not be acceptable for nitrous oxide service.

a)Metals: Brass; Carbon Steel; Zinc; Copper; Monel

b)Plastics: Kel-F; Tefzel; Kynar; PVC

c)Elastomers: Viton; Buna-N; Neoprene; Polyurethane
Key Properties:

Nitrous oxide is a weak anaesthetic, it vigorously accelerates
combustion and is soluble in water.
Physical and Chemical Properties (Metric):

MOLECULAR WEIGHT: 44.0128

SPECIFIC GRAVITY
(Air = 1) at 70°F (21.1°C) and 1 atm: 1.5297

GAS DENSITY
at 70°F (21.1°C) and 1 atm: 0.1146 lb/ft 3 (1.947 kg/m 3 )

VAPOR PRESSURE
at 70°F (21.1°C) 735 psig (5070 kPa)

SOLUBILITY IN WATER
vol/vol at 68°F (20°C) and 1 atm 0.68

BOILING POINT
at 1 atm -127.4°F (-88.5°C)

MELTING POINT
at 1 atm -131.5°F (-90.8°C)
Applications:

1. As a base anaesthetic generally supplemented by other agents.

2. Extensively used as an analgesic and also in cryosurgery.

3. Exceptionally, as an engine boosting fuel for “Dragsters” where
special safety precautions are essential.

4. Propellant for aerosol products such as whipped cream, cosmetics,
shaving cream and some insect sprays

5.Used as the oxidizing agent of combustion gases for atomic
absorption spectrometry.

6. Used in medical applications, and in certain food processing
applications.

7. Semiconductor fabrication

8. Used in combination with Silane for chemical vapour deposition
(CVD) of Silicone Nitride layers.

9. Used in Rapid Thermal Processing to grow high quality gate
oxides.
Production of Nirous oxide:

Nitrous oxide is obtained from the continuous thermal decomposition
of ammonium nitrate. After several purification stages, the nitrous
oxide is compressed, dried and liquefied for storage
Safety:

EFFECTS OF A SINGLE (ACUTE) OVEREXPOSURE:

1.INHALATION
May cause excitation, dizziness, drowsiness, poor coordination, and
narcosis. Exposure to concentrations of 50% or greater will produce
clinical anesthesia. High concentrations may cause asphyxia and
death from lack of oxygen.

2.SKIN CONTACT
No harm expected from gas. Liquid may cause frostbite.

3.SWALLOWING
An unlikely route of exposure. This product is a gas at normal
temperature and pressure, but frostbite of the lips and mouth may
result from contact with the liquid.

4.EYE CONTACT
No harm expected from gas. Liquid may cause frostbite.
Effects due to overexposure:

1.EFFECTS OF REPEATED (CHRONIC) OVEREXPOSURE
Metabolic injury to the nervous system has resulted from frequent
exposure to anesthetic concentrations of nitrous oxide. Complaints
include numbness, tingling of hands and legs, loss of feeling in
fingers, poor balance, and muscular weakness.

2.OTHER EFFECTS OF OVEREXPOSURE
Nitrous oxide is an asphyxiant. Lack of oxygen can kill.

3.MEDICAL CONDITIONS AGGRAVATED BY OVEREXPOSURE
Pregnant women should avoid exposure to nitrous oxide.

4.SIGNIFICANT LABORATORY DATA WITH POSSIBLE RELEVANCE TO HUMAN
HEALTH HAZARD EVALUATION
Exposure to nitrous oxide has produced embryofetal toxicity in
laboratory animals as evidenced by reduced fetal weight, delayed
ossification, and increased incidence of visceral and skeletal
variations. Exposure to nitrous oxide may be associated with an
increased incidence of abortion in humans. Single prolonged exposure
to high concentrations of nitrous oxide has resulted in bone marrow
injury and adverse effects on the blood.

5.CARCINOGENICITY
Nitrous oxide is not listed by NTP, OSHA, or IARC.
Handling and Storage

PRECAUTIONS TO BE TAKEN IN STORAGE:

1.Store and use with adequate ventilation, away from oil, grease,
and other hydrocarbons.

2.Separate nitrous oxide cylinders from flammables by at 20 ft (6.1
m) or use a barricade of noncombustible material. This barricade
should be at least 5 ft (1.53 m) high and have a fire resistance
rating of at least ¨ö hour.

3.Firmly secure cylinders upright to keep them from falling or being
knocked over.

4.Screw valve protection cap firmly in place by hand. Store only
where temperature will not exceed 125ò§…F (52ò§…C).

5.Store full and empty cylinders separately.

6.Use a first-in, first-out inventory system to prevent storing full
cylinders for long periods.
PRECAUTIONS TO BE TAKEN IN HANDLING:

1.Protect cylinders from damage.

2.Use a suitable hand truck to move cylinders; do not drag, roll,
slide, or drop.

3.Never attempt to lift a cylinder by its cap; the cap is intended
solely to protect the valve.

4.Never insert an object (e.g., wrench, screwdriver, pry bar) into
cap openings; doing so may damage the valve and cause a leak.

5. Use an adjustable strap wrench to remove over-tight or rusted
caps.

6.Open valve slowly. If valve is hard to open, discontinue use and
contact your supplier.

7.Never apply flame or localized heat directly to any part of the
cylinder.

8.High temperatures may damage the cylinder and could cause the
pressure relief device to fail prematurely, venting the cylinder
contents.

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