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CHEMINFO Record Number: 790
CCOHS Chemical Name: Neon liquid

Liquid neon
Neon, refrigerated liquid
Neon liquide

CAS Registry Number: 7440-01-9
UN/NA Number(s): 1913
RTECS Number(s): QP4450000
Chemical Family: Noble gas / inert gas
Molecular Formula: Ne
Structural Formula: Ne


Appearance and Odour:
Colourless, odourless, extremely cold liquid.(2)

Odour Threshold:
Odourless liquid.

Warning Properties:
NONE - Odourless, colourless liquid. Simple asphyxiant.

Neon is shipped as a liquefied, cryogenic gas in special insulated containers.(8,9) It is available in grades with a purity of 99.7 to 99.99 mole percent.(8,9,10) Neon is normally available compressed in high pressure steel cylinders at varying pressures depending on the cylinder size, and also in 1 litre quantities in glass flasks at atmospheric pressure. See CHEMINFO record 146 for information on neon gas.

Uses and Occurrences:
Neon is normally present in air at an approximate concentration of 18 ppm. Although neon may be produced, transported and stored as a cryogenic liquid, it is ultimately used as a gas at normal temperatures. See CHEMINFO 146 for the uses of neon gas.
Liquid neon may be used for cryogenic refrigeration and in liquid-neon baths when the use of liquid hydrogen may be too dangerous.


Colourless, odourless, extremely cold liquid. Will not burn. COMPRESSED GAS. Simple asphyxiant. Can displace oxygen in air. Confined space hazard. May cause frostbite.


Effects of Short-Term (Acute) Exposure

Neon gas is not toxic at normal temperature and pressure. However, neon is a simple asphyxiant. Simple asphyxiants can displace oxygen in the air, especially in a confined space. The lack of oxygen then causes the victim to suffocate.
Air normally contains approximately 0.0018% (18 ppm) neon and 20.9% oxygen. At 15-16% oxygen, symptoms of sleepiness, fatigue, loss of coordination, errors in judgment and confusion are masked by a state of euphoria, giving the victim a false sense of security and well-being. An oxygen concentration of 12% or lower can cause unconsciousness quickly and without warning. In some cases, disturbed respiration, abnormal fatigue, nausea and vomiting. Concentrations below 6% can result in respiratory collapse and death.(1,2,4) Since exercise increases the body's need for oxygen, symptoms will occur more quickly during exertion in an oxygen-deficient environment.(1) If the victim survives some or all organs, including the central nervous system and brain, may show damage due to oxygen deprivation. These effects may be reversible with time, depending on the degree and duration of the oxygen deprivation and the extent of the injury.(1,2)
Small amounts of liquid neon can evaporate into very large volumes of gas. For example, one litre of liquid neon vaporizes to 1445 litres of neon gas when warmed to room temperature (21 deg C at 1 atmosphere).(4)
Super-cooled vapours, such as those released from liquid neon, can cause frostbite of the upper airways following prolonged exposure. Accumulation of fluid, inflammation, and blisters can result with eventual tissue death and ulceration in the areas of greatest exposure.(5,6)

Skin Contact:
Direct contact with liquid neon or prolonged exposure to the chilled gas can produce frostbite. Symptoms of mild frostbite include numbness, prickling and itching of the affected area. Symptoms of more severe frostbite include a burning sensation and stiffness of the affected area. The skin may become waxy white or yellow. Blistering, necrosis (dead skin) and gangrene have developed in several cases. There may be no pain experienced at first, but there is intense pain when the frozen tissue thaws.(5,7)
Unprotected skin can stick to metal that is cooled by cryogenic liquids, such as liquid neon. The skin can then tear when pulled away.(5) Cryogenic liquids will quickly penetrate woven or other porous clothing materials which will then stick to the skin.(2)

Eye Contact:
Direct contact with liquid neon or prolonged contact with the chilled gas can cause frostbite of the eyes. Permanent eye damage or blindness can result. There are no reports of accidental injury from splash contact of liquid neon with the eyes.

Ingestion is not an applicable route of exposure for liquid neon.

Effects of Long-Term (Chronic) Exposure

No effects of long-term exposure have been reported.


There is no human or animal information available.

The International Agency for Research on Cancer (IARC) has not evaluated the carcinogenicity of this chemical.

The American Conference of Governmental Industrial Hygienists (ACGIH) has not assigned a carcinogenicity designation to this chemical.

The US National Toxicology Program (NTP) has not listed this chemical in its report on carcinogens.

Teratogenicity and Embryotoxicity:
There is no human or animal information available.

Reproductive Toxicity:
There is no human or animal information available.

There is no information available.

Toxicologically Synergistic Materials:
There is no information available.

Potential for Accumulation:
Neon does not accumulate in the body under normal pressure.

Health Comments:
People working at low temperatures, such as workplaces where liquid neon is used as a refrigerant, may be at risk of developing reduced body temperature (hypothermia). Symptoms may include slowing down of physical and mental responses; irritability; difficulty in speech or vision; cramps and shivers.(2,7) Susceptibility depends on the length of exposure, temperature and the individual.


Take proper precautions to ensure your own safety before attempting rescue (e.g. wear appropriate protective equipment, use the "buddy" system). Remove source of contamination or move victim to fresh air. If breathing is difficult, oxygen may be beneficial if administered by trained personnel, preferably on a doctor's advice. If breathing has stopped, trained personnel should begin artificial respiration (AR) or, if the heart has stopped, cardiopulmonary resuscitation (CPR) immediately. Immediately transport victim to an emergency care facility.

Skin Contact:
If frostbite develops, quickly remove victim from source of contamination and briefly flush with lukewarm, gently flowing water until the chemical is removed. DO NOT attempt to rewarm the affected area on site. DO NOT rub area or apply dry heat. Gently remove clothing or jewelry that may restrict circulation. Carefully cut around clothing or jewelry that sticks to the skin and remove the rest of the garment. Loosely cover the affected area with a sterile dressing. DO NOT allow the victim to drink alcohol or smoke. Quickly transport victim to an emergency care facility.

Eye Contact:
If frostbite develops, quickly remove the victim from the source of contamination. Immediately and briefly flush with lukewarm, gently flowing water until the chemical is removed. DO NOT attempt to rewarm. Cover both eyes with a sterile dressing. DO NOT allow victim to drink alcohol or smoke. Quickly transport victim to an emergency care facility.

Ingestion is not an applicable route of exposure for gases.

First Aid Comments:
Provide general supportive measures (comfort, warmth, rest). Consult a doctor and/or the nearest Poison Control Centre for all exposures except minor instances of inhalation or skin contact.
Some recommendations in the above sections, such as administration of oxygen, may be considered medical acts in some jurisdictions. These recommendations should be reviewed with a doctor and appropriate delegation of authority obtained, as required. All first aid procedures should be periodically reviewed by a doctor familiar with the material and its conditions of use in the workplace.


Flash Point:
Non-flammable liquid or gas

Lower Flammable (Explosive) Limit (LFL/LEL):
Not applicable

Upper Flammable (Explosive) Limit (UFL/UEL):
Not applicable

Autoignition (Ignition) Temperature:
Not applicable

Sensitivity to Mechanical Impact:
Stable liquid or gas. Not sensitive.

Sensitivity to Static Charge:
Information not available for liquid neon.

Combustion and Thermal Decomposition Products:
None known

Fire Hazard Summary:
Neon does not burn. The volume of a given quantity of liquid neon at 101.33 kPa and -246 deg C increases 1445 times when warmed to room temperature (21 deg C and 101.33 KPa).(4) Closed neon-containing containers may rupture or explode due to overpressurization when allowed to warm or in the heat of fire. Neon can displace air to the point where there is not enough oxygen to breathe. Cryogenic liquids can be particularly dangerous during fires because of their potential to rapidly freeze water. Careless use of water can lead to heavy icing, possibly blocking pressure relief valves.(5) Furthermore, relatively warm water greatly increases the evaporation rate of the neon. If large concentrations of neon gas are present, the water vapour in the surrounding air will condense, creating a dense fog that may make it difficult to find fire exits or equipment.(11)

Extinguishing Media:
Use extinguishing media appropriate for surrounding fire.

Fire Fighting Instructions:
Evacuate area and fight fire from a safe distance or a protected location.
If a fire occurs in an area where neon cylinders or containers are used or stored, move cylinder or container from fire area if it can be done without risk. Carefully use water in large quantities, preferably in spray form, to cool fire-exposed containers and equipment. Reverse flow into cylinder may cause rupture. Take care not to block pressure relief valves. Stay away from ends of tanks, but be aware that flying material from ruptured tanks may travel in any direction. Withdraw immediately in case of rising sounds from venting safety device or any discolouration of tanks due to fire. If possible, avoid spraying cold areas of equipment. If it is desirable to evaporate a liquefied neon spill quickly, water spray may be used to increase the rate of evaporation if the increased vapour evolution can be controlled. DO NOT discharge a solid stream of water into liquid neon.
If liquid neon is discharging into the air, judgment should be used in deciding whether to allow the gas to escape, with the possible risk of asphyxiation, or to attempt to cut off the gas flow, depending on which is safer.(4) Where asphyxiation is not a factor, it is preferable to let the gas escape.
Firefighters may enter the area if positive pressure self- contained apparatus (MSHA/NIOSH approved or equivalent) and full Bunker Gear is worn.


NFPA - Comments:
NFPA has no listing for this chemical in Codes 49 or 325.


Molecular Weight: 20.183

Conversion Factor:
1 ppm = 0.82 mg/m3; 1 mg/m3 = 1.21 ppm at 25 deg C (calculated)

Physical State: Gas
Melting Point: -248.7 deg C (-415.6 deg F) (8,12)
Boiling Point: -246 deg C (-410.9 deg F) (8,10)
Relative Density (Specific Gravity): Not applicable (gas)
Solubility in Water: Not applicable
Solubility in Other Liquids: Not available
Coefficient of Oil/Water Distribution (Partition Coefficient): Not available
pH Value: Not applicable
Viscosity-Dynamic: 0.124 mPa.s (0.124 centipoise) at - 246 deg C (10)
Vapour Density: 0.696 at 21.1 deg C (70 deg F) and 101.3 kPa (air = 1) (8)
Vapour Pressure: 101.3 kPa at -246 deg C (9)
Vapour Pressure at 50 deg C: Greater than 7000 kPa (69 atm) (estimated from graph) (8b)
Saturation Vapour Concentration: Not applicable for gases
Evaporation Rate: Rapid, unless the liquid neon is contained in a well- insulated vessel.
Critical Temperature: -228.8 deg C (-379.8 deg F or 44.40 deg K) (8,10)
Critical Pressure: 2,654 kPa absolute (384.9 psia or 26.19 atmospheres) (8,10,13)

Other Physical Properties:
TRIPLE POINT: -248.6 deg C (-415.5 deg F or 24.56 deg K) at 43.4 kPa absolute (8,10)


Normally stable.

Hazardous Polymerization:
Does not occur.

Incompatibility - Materials to Avoid:

NOTE: Chemical reactions that could result in a hazardous situation (e.g. generation of flammable or toxic chemicals, fire or detonation) are listed here. Many of these reactions can be done safely if specific control measures (e.g. cooling of the reaction) are in place. Although not intended to be complete, an overview of important reactions involving common chemicals is provided to assist in the development of safe work practices.

Neon is inert and unreactive.

Hazardous Decomposition Products:
None known

Conditions to Avoid:

Corrosivity to Metals:
Neon gas is not corrosive.(8)

Stability and Reactivity Comments:
When in contact with refrigerated or liquid neon, many materials (e.g. carbon steel) become brittle and are likely to break without warning.(2)
If liquid neon is exposed to air, oxygen from the air may condense into the liquid neon, resulting in a potential oxygen-enrichment hazard.(2) Liquid neon may then present the same hazards as liquid oxygen and could react violently with many organic materials, such as oil and grease.(2,14)
Liquid neon can condense and freeze most other gases, except hydrogen and helium. Therefore, there is the danger of pipes or vents becoming plugged with liquefied gases or air.(2)


There is no animal toxicity information available.


Selected Bibliography:
(1) Wilkenfeld, M. Simple asphyxiants. In: Environmental and occupational medicine. 2nd ed. Edited by W.N. Rom. Little, Brown and Company, 1992. p. 535-538
(2) British Cryogenics Council. Cryogenics safety manual: a guide to good practice. 3rd ed. Butterworth Heinemann, 1991. p. 1-26, 94-100
(3) Casarett and Doull's toxicology : the basic science of poisons. 3rd ed. Macmillan Publishing Company, 1986. p. 359-362
(4) Compressed Gas Association. Safety guidelines for compressed gases and cryogenic liquids. In: Handbook of compressed gases. 3rd ed. Chapman and Hall, 1990. p. 70-92
(5) Riklik, L. How to work safely with cryogenic liquids (P90-24E). Canadian Centre for Occupational Health and Safety, 1990
(6) Rockswold, G., et al. Inhalation of liquid nitrogen vapour. Annals of Emergency Medicine. Vol. 11, no. 10 (Oct. 1982). p. 553-555
(7) Code of practice for safe operation of small-scale storage facilities for cryogenic liquids. (BS 5429 : 1976). British Standards Institution, 1976
(8a) Compressed Gas Association. Rare gases: krypton, neon, xenon. In: Handbook of compressed gases. 3rd ed. Chapman and Hall, 1990. p. 549-555
(8b) Yaws, C.L. Matheson gas data book. 7th ed. McGraw-Hill, 2001. p. 580
(9) Braker, W., et al. Neon. In: Matheson gas data book. 6th ed. Matheson Gas Products, 1980. p. 504-508
(10) Hwang, S-C., et al. Helium group: gases. In: Kirk-Othmer encyclopedia of chemical technology. 4th ed. Vol. 13. John Wiley and Sons, 1995. p. 1-38
(11) Matheson guide to safe handling of compressed gases. Matheson Gas Products, Inc., 1983
(12) Haussinger, P., et al. Noble gases. In: Ullmann's encyclopedia of industrial chemistry. 5th completely revised ed. Vol. A 17. VCH Verlagsgesellschaft, 1991. p. 485-539
(13) The Merck index: an encyclopedia of chemicals, drugs, and biologicals. 12th ed. Merck and Co., Inc., 1996
(14) Urben, P.G., ed. Bretherick's handbook of reactive chemical hazards. 5th ed. Vol. 1. Butterworth- Heinemann, Ltd., 1995. p. 1683

Information on chemicals reviewed in the CHEMINFO database is drawn from a number of publicly available sources. A list of general references used to compile CHEMINFO records is available in the database Help.

Review/Preparation Date: 2000-01-04

Revision Indicators:
TDG 2002-05-29
WHMIS disclosure list 2003-07-09
Carcinogenicity 2003-07-09
PEL-TWA transitional 2003-12-19
Bibliography 2006-01-17
Vapour pressure at 50 deg C 2006-01-17
Relative density 2006-09-28

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