Standards · IS 307 · IS 7285 (Part 1):2018 · IS 3224:2021
IS 307: the Indian Standard for carbon dioxide and its black cylinder
Carbon dioxide in India is specified by IS 307, filled into seamless steel cylinders to IS 7285 Part 1 and valved to IS 3224. Under IS 4379 the cylinder is black with a white neck band — the band being the only thing on the paintwork separating it from oxygen. Retest is every 5 years.
- Gas specification
- IS 307
- Cylinder construction
- IS 7285
- Cylinder identification
- Black ground with a white or aluminium neck band
- Shares a ground colour with
- Oxygen
- Periodic retest
- Every 5 years
What IS 307 covers
IS 307, Carbon Dioxide, is the Indian Standard specifying carbon dioxide as a product. It is one of the older standards in this cluster and has been reaffirmed rather than revised — normal for a gas whose specification has not needed to move.
If you are writing a tender clause, check the BIS catalogue on the day rather than trusting a reaffirmation date printed on a supplier’s brochure. That advice applies to every standard on this site, but it applies most to the old ones.
The black cylinder problem
This is the part that matters more than the specification.
Under IS 4379, carbon dioxide and oxygen are both black cylinders. The only thing separating them on the paintwork is a white or aluminium neck band on the carbon dioxide.
That band is not a robust signal:
- it fades in sunlight and weather
- it gets overpainted during refurbishment
- it disappears entirely under a coat of workshop grime
So the rule in every plant we supply is the same, and it is worth putting on a wall: colour tells you where to look, the stamping tells you what it is. IS 4379 requires the cylinder to be marked with the gas name and chemical formula, and every cylinder carries stamped identification on the shoulder. Read it, then read the label. Colour is the third check.
Why the gauge lies
Carbon dioxide is liquefied in the cylinder, not merely compressed. What the valve gauge reads is the vapour pressure above the liquid, and that stays roughly constant while any liquid remains — so a gauge showing healthy pressure tells you almost nothing about how much gas is left.
Content is established by weight, against the tare stamped on the cylinder. A CO₂ cylinder that feels light is nearly empty whatever the gauge says.
The standards that go with it
| Standard | What it governs |
|---|---|
| IS 7285 (Part 1) | The seamless steel cylinder |
| IS 3224 | The valve |
| IS 4379 | Black ground, white or aluminium neck band |
| IS 8451 | Five-yearly hydrostatic retest |
How KIGL fills it
Carbon dioxide is filled to IS 307 at the Guwahati works, into cylinders built and requalified to the standards above, painted and marked so the contents can be identified before anyone connects anything.
One thing to raise when you enquire: if your use is food, beverage or anything ingested, say so. Those applications carry purity and impurity requirements beyond the industrial specification, and industrial grade should never be assumed suitable for them. See carbon dioxide for supply detail.
IS 307 — frequently asked questions
Which Indian Standard specifies carbon dioxide?
IS 307. It is an older standard than most in this cluster and has been reaffirmed rather than revised, which is common for a gas whose specification has not needed to change. If a tender asks for the current edition, check the BIS catalogue on the day rather than relying on a reaffirmation date printed on a supplier's document.
Why is a CO₂ cylinder black, like oxygen?
Because IS 4379 assigns black as the ground colour to both, and separates them with a neck band — white or aluminium on carbon dioxide, none on oxygen. It is the single most consequential ambiguity in the Indian colour scheme, and it is why colour must never be your only check. A band fades, gets overpainted during refurbishment and disappears under workshop grime.
What happens if CO₂ is connected where oxygen was expected?
Carbon dioxide will not support combustion, so a cutting set simply will not light — that is the harmless failure, and it is the one most people meet. The dangerous version is any application where a person is relying on the gas. Read the stamped marking on the shoulder before connecting anything; the paint is the third check, not the first.
Is food-grade carbon dioxide the same specification?
No. Beverage and food use carries additional purity and impurity requirements beyond the industrial specification, and that is a different conversation from the one this page is having. If your application is food, beverage or anything ingested, say so when you enquire — do not assume industrial grade is suitable.
Why is a CO₂ cylinder weighed rather than pressure-checked?
Because carbon dioxide is liquefied in the cylinder. The pressure at the valve reflects the vapour above the liquid and stays roughly constant while liquid remains, so a gauge tells you very little about how much is left. Content is established by weight, against the tare stamped on the cylinder.
How often must a CO₂ cylinder be retested?
Every five years, hydrostatically, to IS 8451:2018 — the same as the other compressed gases. Dissolved acetylene is the exception at two years, because its cylinders contain a porous mass and solvent and are inspected to IS 8433 instead.
Enquiries
Request a quotation
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 our agent network.