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General information about regulations and labeling, not medical advice. For a patient’s oxygen supply, follow the prescriber’s and the supplier’s instructions.
Short answer
Oxygen in a cylinder is covered by two different date systems. A drug-product expiration date is required by 21 CFR 211.137 and is set by stability testing; the rule lists no exemption for medical gases. Separately, the steel or aluminum cylinder carries a DOT requalification stamp, with intervals of 5, 10 or 12 years. The two dates answer different questions.
Definition and scope
This page separates three things people call an “oxygen tank expiration date”: the expiration date a drug product must bear, the retest interval for the cylinder as a pressure vessel, and the label content the medical gas rules require. It covers medical oxygen in cylinders in labs, clinics and supply rooms. It does not cover patient dosing or equipment setup. See oxygen cylinder parts for the valve, cap and relief device.
Does medical oxygen have an expiration date? What 21 CFR 211.137 requires
Under 21 CFR 211.137(a), a drug product must bear an expiration date determined by appropriate stability testing, so that it meets its standards of identity, strength, quality and purity at the time of use. Paragraph (b) ties the date to the storage conditions stated on the labeling. Paragraph (d) sends the placement of the date to 21 CFR 201.17, which puts it on the immediate container and on the outer package, if any, unless it is easily legible through the package.
The exemptions in section 211.137 are homeopathic drug products, allergenic extracts labeled “No U.S. Standard of Potency”, investigational new drug products, and, under paragraph (h), certain OTC products without dosage limitations that are stable for at least 3 years (enforcement is paused pending a proposed exemption). Medical gases are not listed. Medical gas labeling has its own section, 21 CFR 201.328, which sets the “For Medical Use” or “Medical Gas” wording, shoulder color (green for oxygen, yellow for medical air, blue for nitrous oxide) and 360-degree wraparound labels with gas-name lettering of at least 2 inches on cryogenic containers. That section contains no expiration-date or lot-number rules, so the date question is answered by 211.137 and 201.17 and by the labeling on the specific container.
Cylinder test date vs expiration date
The date stamped into the cylinder shoulder is a requalification date under the Department of Transportation rules, 49 CFR 180.209. It says when the vessel must next be tested, not how long the contents are good for.
| Date or mark | What it governs | Interval or content | Rule |
|---|---|---|---|
| Expiration date on the product label | The drug product (the gas as labeled) | Set by stability testing and related to labeled storage conditions; printed on the container and outer package | 21 CFR 211.137, 201.17 |
| Requalification stamp, DOT 3A and 3AA steel | The cylinder as a pressure vessel | 5, 10 or 12 years depending on the paragraph of 180.209 that applies | 49 CFR 180.209, Table 1 |
| Requalification stamp, DOT 3AL aluminum | The cylinder as a pressure vessel | 5 or 12 years | 49 CFR 180.209, Table 1, (j), (m) |
| Medical gas label and shoulder color | Identification of the gas | Wording, green shoulder for oxygen, lettering size on cryogenic containers; no expiration rule | 21 CFR 201.328 |
Oxygen tank expiration date: reading the stamp
The oxygen cylinder label and markings guide shows how to read the DOT stamp, and compressed gas cylinder sizes covers how cylinders are sized.
Aluminum 6351-T6 cylinders in oxygen service
Paragraph (m) of 180.209 adds a stricter check for DOT 3AL cylinders made of aluminum alloy 6351-T6 used in SCUBA, SCBA or oxygen service. They must be requalified and inspected for sustained load cracking by eddy current examination combined with visual inspection, with a 5-year requalification period. A cylinder with a crack in the neck or shoulder of 2 thread lengths or more is condemned. The paragraph does not apply to cylinders used for carbon dioxide, fire extinguisher or other industrial gas service.
Oxygen cylinder storage: what OSHA 1910.101 points to
For employers, 29 CFR 1910.101(a) requires that compressed gas cylinders under their control be in a safe condition as far as visual inspection can determine, with inspections conducted as prescribed in the DOT Hazardous Materials Regulations. Paragraph (b) requires in-plant handling, storage and use of compressed gases in cylinders to follow Compressed Gas Association Pamphlet P-1-1965 (see CGA Pamphlet P-1). Paragraph (c) covers pressure relief devices, which follow CGA pamphlets S-1.1 and S-1.2.
For cart-based storage and restocking, see oxygen tank carts; for fire-safety handling around oxygen, see home oxygen safety.
Checklist: which date to check, and who owns it
- Product label: is an expiration date printed on the container or outer package (21 CFR 201.17)?
- Cylinder shoulder: is the requalification date within the interval that applies to that cylinder type (49 CFR 180.209)?
- Aluminum 6351-T6 cylinders in oxygen service: has the 5-year eddy current and visual inspection been done (180.209(m))?
- Facility: are cylinders inspected as the DOT regulations prescribe and stored per CGA P-1 (29 CFR 1910.101(a), (b))?
Common misunderstandings
- The stamped date is not a product expiration date. It is a requalification date for the vessel.
- The color on the shoulder identifies the gas under 21 CFR 201.328; it says nothing about age.
- Passing a requalification test does not replace a label expiration date, and a label date does not replace requalification.
- Rules for one gas do not carry over: the 6351-T6 inspection applies to the listed services and not to carbon dioxide or fire extinguisher cylinders.
FAQ
Does an oxygen tank have an expiration date?
Two dates may apply: the expiration date the drug-product rule requires on the labeling (21 CFR 211.137, 201.17) and the DOT requalification date stamped on the cylinder (49 CFR 180.209). Check the container’s own labeling for the first and the shoulder stamp for the second.
Does medical oxygen expire?
21 CFR 211.137 requires an expiration date, based on stability testing, on a drug product, and its exemption list does not include medical gases. The date that applies to a given cylinder is the one printed on its labeling.
What are the medical gas cylinder storage requirements?
For employers, OSHA 29 CFR 1910.101(b) points to CGA Pamphlet P-1 for in-plant handling, storage and use of compressed gases in cylinders, and 1910.101(a) requires cylinders to be inspected as the DOT regulations prescribe.
How often is an oxygen cylinder tested?
Under 49 CFR 180.209, DOT 3A and 3AA steel cylinders are requalified every 5, 10 or 12 years and DOT 3AL aluminum cylinders every 5 or 12 years, depending on the applicable paragraph. See also whether hydrogen peroxide expires for a different product with a different date logic.
Sources
- 21 CFR 211.137, Expiration dating. law.cornell.edu/cfr/text/21/211.137 (checked 2026-10-30)
- 21 CFR 201.17, Location of expiration date. ecfr.gov, 21 CFR 201.17 (checked 2026-10-30)
- 21 CFR 201.328, Medical gases labeling. ecfr.gov, 21 CFR 201.328 (checked 2026-10-30)
- 49 CFR 180.209, Requalification of specification cylinders. law.cornell.edu/cfr/text/49/180.209 (checked 2026-10-30)
- 29 CFR 1910.101, Compressed gases (general requirements). law.cornell.edu/cfr/text/29/1910.101 (checked 2026-10-30)
