Moving one or two compressed gas cylinders is an exercise in simplicity: One merely rolls over a cylinder cart, sets and secures the cylinders in place, and moves everything to another location. Essentially a modified hand truck, cylinder carts are available for any work areas, from smooth shop floors to rough construction sites.

Most carts are designed for the purpose of cylinder transportation only, but on a construction site, keeping cylinders on a cart for extended periods of time — especially if one cylinder is oxygen and the other is acetylene — is both a safety hazard and an OSHA violation, unless the cart has one additional modification.

Reducing fire hazard
While it is convenient for many jobs to keep oxygen and acetylene cylinders at the ready on a cylinder cart, safety dictates that the carts used at a construction site should have a firewall installed between the two cylinders. The design of such a firewall is described in OSHA standard 1926.350(a)(10):

"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 reason to have a separation/firewall standard is to prevent the spread of fire and multicylinder explosions in the event that a single cylinder leaks and a fire begins. Both storage options — separation and firewall — usually will require an employer to set up a storage area some distance from the welding or cutting area.

Proper cylinder handling requires regulators to be removed and re-installed, and the cylinders capped and uncapped numerous times over the course of a day or two, increasing wear on tank and regulator threads, and the risk of gas leaks and tank damage.

The firewall is more than a thick sheet of material. OSHA standard 29 CFR 1926.350(a)(10) says a fire wall is a "patented engineered steel fire barrier." And, it must be high enough to completely shield one cylinder from another.

Construction, or general industry
OSHA requires a firewall on a gas cylinder cart used on a construction site because the differences in "interpretations of the respective provisions is in part attributable to the language of the respective standards. The language of 1910.253 indicates that cylinders are in ‘storage' if they are not in use or connected for use. Under the language of 1926.350, cylinders could be subject to the storage requirements even though the cylinders are connected for use." In interpreting the term "storage" in 1926.350, therefore, OSHA has focused on balancing the standard's purposes and the dynamics of a construction environment.

OSHA further explains that, "in general industry workplaces, oxygen and acetylene cylinders that are in use or are connected for use will not be considered to be in ‘storage' for purposes of the 1910.253 storage requirements. OSHA also will not cite a general industry employer if a single oxygen cylinder and a single acetylene cylinder are maintained with their cylinder valves closed and valve protection caps affixed. Closing the valves and affixing the valve protection caps can provide an equivalent level of protection to that achieved when the two cylinders are connected to a properly functioning regulator." Such a set-up would appear to apply to usage of a gas cylinder cart.

Two construction companies in the state of New York were handed fines of more than $25,000 and $33,000 for violations that included improper storage of gas cylinders, in February 2005. Other sites have even been shut down. Unless a site manager can document that gas cylinders had been used in the previous 24 hours, it is better, and less costly, to ensure any carts holding gas cylinders on site meet the OSHA specifications.