There is no Federal OSHA requirement specifically addressing the use of compressed air to test for leaks in gas lines, according to an OSHA letter of interpretation sent in response to a compliance inquiry. Then- Director of the Office of Construction and Compliance Assistance Gerald P. Reidy noted that there are several applicable general industry and construction standards addressing the hazards of compressed gases.
In the construction standard, Subpart J, Welding and cutting, §1926.350.(c)(2) and (3) require that:
(2) "No one shall use a cylinder's contents for purposes other than those intended by the supplier. All cylinders used shall meet the Department of Transportation requirements published in 49 CFR part 178, subpart C, Specifications for cylinders."
(3) "No damaged or defective cylinders shall be used."
According to Reidy; “If compressed gas cylinders or containers are used for purposes of pressure testing, the containers and their use must meet the applicable DOT requirements. Also, as you are aware, where there is no specific standard covering an industry recognized hazard, Section 5(a)(1) of the OSH Act requires the duty of employers to "... furnish to each of his employees employment and a place of employment which are free from recognized hazards that are causing or are likely to cause death or serious physical harm to his employees." In such cases, the hazard must be recognized as a serious hazard by the industry and by the employer and there must be feasible means of abatement. For Section 5(a)(1) to be applicable, of course, employees must be exposed to potential injury or illness as a result of the hazard.”