Guidelines for Maintaining the Integrity of Gas Cylinders
- Cal-OSHA requires that all portable cylinders used for the storage and shipment
of compressed gases be constructed and maintained in accordance with the
regulations of the U. S. Department of Transportation 49 CFR Parts 171-179 [8
- Cylinders are required to be requalified before offering for transportation [49 CFR 173.34(e)].
- If a cylinder is beyond its requalification period and empty, it can be
offered for transportation and requalified provided its service life has not
- If a cylinder is beyond its requalification period and partially full, it can
only be offered for transportation one way to a treatment/disposal facility.
There is no prohibition on using all of the product for its intended purpose to
have the cylinder become eligible for requalification. However, the purpose of
requalification is to ensure the integrity of the cylinder while in commerce.
Therefore, requalification must be attained within one requalification period
from the date the requalification was due for that cylinder or given to EH&S for
disposal. For example, a 3AA argon cylinder with a 01/01/2001 expired
requalification stamp must be used by 01/01/2011 (a 10 year requalification
period). See 49 CFR 173.34(e) & (e)(7) for requalification periods and
- The size of the gas cylinder should be matched to the intended use, to prevent
cylinders from exceeding their requalification test period. This will prevent the
generation of partially full cylinders (hazardous waste). It is illegal to treat
hazardous compressed gases by discharging to the air for the purpose of emptying
- D.O.T. restricts filling and offering a cylinder for transportation after its
authorized service life has expired. Only some specification cylinders have a
fixed service life. See cylinder specific requirements in 49 CFR 178. Cylinders
that have reached the end of their service life must be returned to the supplier or
given to EH&S for disposal.
- In the past, State procurement policy pushed campuses toward owning their own
cylinders to prevent paying fees on cylinder rental. When changing out empty
University owned cylinders, exchange for vendor supplied requalified cylinders or
request requalification if the same cylinder is to be refilled; approximately $20.00 per cylinder).