How to Store Gas Cylinders: OSHA Rules for Shops and Job Sites

Cylinder storage citations are among the easiest for an inspector to write: the violation is visible from across the shop. An oxygen bottle parked next to the acetylene rack, a cylinder leaning unchained against a bench, a cap sitting on the shelf instead of on the valve. Each one is a line item on an OSHA citation or an insurance carrier's walkthrough report, and each one has a specific rule behind it.

This guide translates those rules into plain English for shop owners and safety managers: the 20 foot separation rule and its barrier alternative, the in-use vs in-storage distinction that decides whether the rules apply to your welding cart at all, and the securing, capping, and location details that make up the rest of the checklist. The two regulations that matter are OSHA 29 CFR 1910.253 for general industry (your shop) and 29 CFR 1926.350 for construction sites. The full regulatory breakdown of the shop rule lives on our OSHA 1910.253 page; this guide is the practical version.

The headline rule, word for word from 1910.253(b)(4)(iii): oxygen cylinders in storage shall be separated from fuel-gas cylinders or combustible materials (especially oil or grease) "a minimum distance of 20 feet (6.1 m) or by a noncombustible barrier at least 5 feet (1.5 m) high having a fire-resistance rating of at least one-half hour." The construction standard, 1926.350(a)(10), uses the same language.

In practice that gives you two compliant layouts:

• Distance: the oxygen rack and the fuel-gas rack sit at least 20 feet apart, with no oil, grease, or combustible storage filling the gap next to the oxygen.
• Barrier: the racks share a wall section, separated by a noncombustible partition at least 5 feet tall with at least a half-hour fire-resistance rating. Some firewall cylinder carts and racks are built around this barrier concept; verify the barrier height and fire-resistance rating against the rule before relying on one.

Oxygen also has its own neighborhood rules in 1910.253(b)(4)(i): not near highly combustible material, especially oil and grease, not near reserve stocks of carbide and acetylene or other fuel-gas cylinders, and not near any other substance likely to cause or accelerate fire. The deep dive on the separation rule, including diagrams, is in the separation rule section of our 1910.253 page.

The most common storage question is not about racks at all. It is: do I have to separate the oxygen and acetylene cylinders that live together on my welding cart? OSHA has addressed this in standard interpretation letters (May 8, 2006, May 10, 2006, and November 18, 2021), and the answer turns on whether the cylinders are in storage in the first place.

• No more than one acetylene cylinder and one oxygen cylinder on the cart
• The cart is specifically designed to hold and carry oxygen and acetylene cylinders upright
• The cylinders are securely held to the cart by straps, chains, or another securing device
• The cart sits on level ground where it is not at reasonably foreseeable risk of being struck
• Both cylinders either have valves closed with protection caps on, or are connected to a properly functioning regulator

The cart itself matters in that list: it has to be purpose-designed for upright cylinder transport. Picking one, including the firewall-equipped carts that carry their own oxygen and fuel-gas barrier, is covered in our cylinder cart selection guide. OSHA's November 2021 letter adds the transport-design side: carts and trucks for connected cylinders must hold them erect or nearly erect with the valves and regulators protected, and a properly designed trolley holding an acetylene cylinder at up to a 45 degree incline is acceptable.

• Secure cylinders upright. The construction standard says it directly: compressed gas cylinders shall be secured in an upright position at all times, except for short periods while being hoisted or carried (1926.350(a)(9)). Chains, straps, or racks all work; leaning a bottle against the wall does not.
• Acetylene stays valve end up. 1910.253(b)(3)(ii) requires acetylene cylinders to be stored valve end up, which keeps the acetone solvent inside the cylinder where it belongs.
• Caps on, hand-tight. Valve protection caps, where the cylinder is designed to accept one, must always be in place hand-tight, except when cylinders are in use or connected for use (1910.253(b)(2)(iv)).
• Keep cylinders away from radiators and other sources of heat (1910.253(b)(2)).

What the regulation actually requires is short: empty cylinders shall have their valves closed (1910.253(b)(2)(iii)), and the cap rule above applies to empties the same as fulls (where the cylinder is designed to accept a cap). An "empty" fuel-gas cylinder still contains gas at residual pressure, so every storage rule on this page, including the 20 foot separation, applies to it while it waits for pickup.

The familiar shop habits beyond that, separating the empty rack from the full rack and chalking MT on spent bottles, are industry practice rather than OSHA text. They are still worth keeping: they stop a crew member from wrenching a regulator onto a dead bottle mid-job, and they make the supplier swap faster. Just know the difference when an inspector points at your racks: mixed full and empty cylinders of the same gas, valves closed and capped, are not by themselves a 1910.253 violation.

1910.253(b)(2) describes the storage spot itself. Inside buildings, cylinders must be stored in a well-protected, well-ventilated, dry location, at least 20 feet from highly combustible materials such as oil or excelsior. Assigned storage spaces must be located where cylinders will not be knocked over or damaged by passing or falling objects, or subject to tampering by unauthorized persons. The shop standard adds, as a should-level sentence, that cylinders should be stored in definitely assigned places away from elevators, stairs, or gangways; the construction standard makes the same placement mandatory on job sites.

One prohibition is absolute: cylinders shall not be kept in unventilated enclosures such as lockers and cupboards. A leaking fuel-gas cylinder in a closed cabinet turns the cabinet into a mixing chamber. The same no-unventilated-enclosures rule appears in the construction standard (1926.350(a)(11)).

The two standards overlap heavily, but the differences decide citations:

The practical takeaway: a connected torch cart that is fine in your shop can still draw a citation on a construction site if it sits unused past the 24-hour line, unless it meets the cart safe-harbor conditions above. Crews that work both environments can simplify by meeting the cart conditions everywhere; the rest of the handling and storage rules still apply either way.

Walk the shop with this list before the inspector does:

• Oxygen rack at least 20 feet from fuel-gas cylinders and from oil, grease, and combustible storage, or separated by a 5 foot noncombustible barrier rated at least a half hour
• Cylinders secured so they cannot be knocked over, with acetylene valve end up; on construction sites, secured upright at all times per 1926.350(a)(9)
• Caps hand-tight on every cylinder designed to accept one that is not in use or connected for use, empties included
• Empty cylinders: valves closed
• Storage area well-protected, well-ventilated, and dry; nothing stored in unventilated enclosures such as lockers, cupboards, or closed job boxes; assigned places away from elevators, stairs, and gangways (should-level in the shop standard, mandatory on construction sites)
• Cylinders away from radiators and heat sources
• Welding carts: one oxygen plus one acetylene, purpose-built cart, cylinders strapped or chained, on level ground, each cylinder either valve-closed with its cap on or connected to a properly functioning regulator
• Storage spot protected from passing or falling objects and from tampering