Gases
Nitrous oxide, N₂O (laughing gas), supplied for medical and industrial use
Nitrous oxide (N₂O) is used for anaesthesia and analgesia in medicine, often as a 50:50 mixture with oxygen, and as an oxidiser in industry. Medical grade is a licensed medicine to Indian Pharmacopoeia standard. KIGL supplies nitrous oxide rather than producing it. Stored as a liquid and measured by weight.
By Mithillessh Garg, Director (Gas Supply)
- Supplier
- KIGL’s role
- Indian Pharmacopoeia
- Pharmacopoeial standard
- Licensed medicine under the Drugs and Cosmetics Act
- Regulatory basis (medical)
- UN 1070
- UN number
- 2.2 with 5.1 oxidiser subsidiary risk
- Transport class
What nitrous oxide is
Nitrous oxide (N₂O) is a colourless gas with a faintly sweet odour, used in medicine for anaesthesia and analgesia and in industry as an oxidiser.
Two properties govern how it is handled, and both surprise people:
It is stored as a liquid. Like carbon dioxide, N₂O liquefies under its own vapour pressure at ambient temperature. Cylinders are filled and measured by weight, and the pressure gauge is not a contents indicator — it holds steady while liquid remains, then falls away sharply.
It is an oxidiser, despite being non-flammable. N₂O does not burn, but at elevated temperature it decomposes and releases oxygen, so it supports combustion vigorously. In practical terms it should be treated with the same discipline as an oxygen cylinder: no oil, no grease, no ignition sources nearby.
Medical use
Anaesthesia and sedation in operating theatres and dental practice; analgesia in labour and delivery, usually as a 50:50 oxygen mixture; and pre-hospital pain relief in ambulance and emergency care.
Medical nitrous oxide is a licensed medicine, produced under drug licence, filled into dedicated cylinders and released against the Indian Pharmacopoeia monograph. Industrial-grade N₂O must never be substituted, in any circumstance.
KIGL supplies nitrous oxide and does not produce it. Unlike medical oxygen, which KIGL manufactures itself, nitrous oxide is sourced from a licensed producer. That is stated because it affects what can be committed to on lead time, and because the origin of a medical gas should be known.
Industrial use
As an oxidiser in certain combustion and propulsion applications; in semiconductor manufacture; and in atomic absorption spectroscopy, where a nitrous oxide-acetylene flame burns hotter than air-acetylene and allows determination of refractory elements that a cooler flame cannot dissociate. For that application, pair it with ultra-high-purity acetylene.
Medical grade against industrial grade
The same molecule, two different products, and the difference is regulatory as much as technical.
Medical nitrous oxide is a pharmaceutical. It is made to the Indian Pharmacopoeia monograph, filled under a drug licence, batch-tested and released against a certificate, and it is traceable from batch to cylinder. The hazard it guards against is specific: nitric oxide and nitrogen dioxide, formed if the manufacturing temperature runs high, are acutely toxic to the lungs at concentrations that would not trouble an industrial user. The monograph exists largely to cap them.
Industrial nitrous oxide is held to a commercial specification. It is the right product for a laboratory or a food application and the wrong one for a patient, and the two must never be substituted in either direction.
For a hospital the practical consequence is a documentary one: the cylinder, the batch certificate and the pipeline all have to tie together for an audit. See medical gas standards.
Inside the cylinder filling shed, every cylinder secured upright in rows
Guwahati works · agent network
Safe handling
Nitrous oxide liquefies under its own pressure at ordinary temperatures, which makes the cylinder behave unlike oxygen or nitrogen.
Why a nitrous oxide cylinder behaves oddly
- The gauge does not tell you the contents It reads the vapour pressure above the liquid, which stays near constant until the liquid is gone and then falls quickly. Weigh the cylinder against its tare.
- The pressure moves with temperature A cylinder in the sun reads considerably higher than the same cylinder in a cool store, and nothing has changed inside it.
- Fast withdrawal chills the cylinder The liquid takes its latent heat from the cylinder, pressure falls and frost appears. Reduce the draw or manifold more cylinders rather than warming it, and never apply a direct heat source.
Is nitrous oxide flammable?
Nitrous oxide does not burn on its own, but it is an oxidiser: above roughly 600–650 °C it decomposes into nitrogen and oxygen and will then make other materials burn vigorously, including oil, grease and some plastics in contact with it. Treat it as you would oxygen — no hydrocarbons on fittings, no heat on the cylinder — not as an inert gas.
Safe handling
Handling
- Treat as an oxidiser. Keep oil, grease and hydrocarbons away from valves and fittings.
- Weigh cylinders to determine contents. Do not rely on the gauge.
- Store upright, secured, ventilated, away from heat and combustible material.
- N₂O is heavier than air and will accumulate at low level in poorly ventilated spaces.
- In theatre, scavenging is required — chronic occupational exposure carries recognised health effects for staff.
Full detail is in the nitrous oxide safety data sheet.
Supply and control
Nitrous oxide is subject to misuse, so legitimate customers should expect supply against verifiable end use. KIGL applies that check deliberately. It protects the integrity of the supply chain, and the clinical and industrial users who depend on it.
Cylinder supply from KIGL's filling operations, with batch documentation for medical grade.
Why KIGL
Why buy nitrous oxide from KIGL
KIGL has worked in industrial and medical gas since 1947, and four generations of the same family have answered for it. Nitrous oxide is supplied from a licensed producer rather than made in-house, which is why KIGL is precise about lead times. Where it matters most is the handling: the gas does not burn, and that single sentence is what gets people into trouble, because it will feed a fire vigorously all the same.
Specification
Nitrous oxide — full specification
| Property | Value | Basis |
|---|---|---|
| KIGL’s role | Supplier — nitrous oxide is not produced by KIGL | Company position |
| Pharmacopoeial standard | Indian Pharmacopoeia (IP) | Indian Pharmacopoeia Commission |
| Regulatory basis (medical) | Licensed medicine under the Drugs and Cosmetics Act | — |
| UN number | UN 1070 | ADR 2025 |
| Transport class | 2.2 with 5.1 oxidiser subsidiary risk | ADR 2025 |
| State in cylinder | Liquid under its own vapour pressure | Physical property |
| Contents measured by | Weight, not pressure | Physical property |
| Chemical formula | N₂O | — |
| Grade, medical | Indian Pharmacopoeia | IP monograph |
| Grade, industrial | Industrial purity | — |
| Appearance | Colourless gas, faintly sweet odour | KIGL nitrous oxide safety data sheet |
| Oxidising properties | Supports combustion — behaves as an oxidiser | GHS |
| Relative vapour density (air = 1) | ≈1.53 — heavier than air | Calculated from molar mass, NIST Chemistry WebBook |
Documents
Nitrous oxide — safety and technical documentation
Questions
Nitrous oxide — frequently asked questions
Is nitrous oxide flammable?
No, but that is misleading in practice. N₂O does not burn, yet it decomposes at high temperature to release oxygen and will therefore support combustion vigorously — it behaves as an oxidiser. Materials that burn slowly in air burn fast in nitrous oxide. Treat it with the same caution as an oxygen cylinder: no oil, no grease, no ignition sources.
How do I tell how much is left in the cylinder?
By weight. N₂O is stored as a liquid, so the pressure gauge reads vapour pressure and stays roughly constant until the liquid is exhausted, then drops abruptly. Weigh the cylinder and compare against the tare weight stamped on it. Relying on the gauge is how a theatre runs out mid-procedure.
What is Entonox and do you supply it?
Entonox is a ready-mixed 50:50 nitrous oxide and oxygen blend used for analgesia, particularly in labour and emergency care. Send KIGL the requirement and it will confirm what it can fill; availability should not be assumed from this page.
Can industrial nitrous oxide be used medically?
No. As with oxygen, the difference is the licence, the dedicated cylinders, the batch record and the pharmacopoeial release specification, not simply the purity figure. Using industrial N₂O on a patient is unlawful and unsafe.
Why is nitrous oxide supply controlled?
Because it is subject to misuse. Legitimate medical and industrial customers should expect supply against a verifiable end use, and KIGL applies that check. It protects the supply chain and the customer.
What are the industrial uses?
As an oxidiser in certain combustion and propulsion applications, in semiconductor manufacture, and as a fuel-flame component in atomic absorption spectroscopy, where the nitrous oxide-acetylene flame reaches temperatures air-acetylene cannot.
References
- Indian Pharmacopoeia Commission. (n.d.). Indian Pharmacopoeia: Indian Pharmacopoeia monographs.
- Linstrom, P. J., & Mallard, W. G. (Eds.). (n.d.). NIST Chemistry WebBook (NIST Standard Reference Database 69). National Institute of Standards and Technology.
- The Kamrup Industrial Gases Limited. (2026). Company information and manufacturer's data [Company statement].
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Enquiries
Request a quotation for nitrous oxide
State the gas or equipment, the quantity or capacity, and your location. KIGL will confirm the grade, the cylinder or plant size, and whether the location can be served from Noonmati, or through the agent network.