OSHA requirements are set by statute, standards and regulations. Our interpretation letters explain these requirements and how they apply to particular circumstances, but they cannot create additional employer obligations. This letter constitutes OSHA's interpretation of the requirements discussed. Note that our enforcement guidance may be affected by changes to OSHA rules. Also, from time to time we update our guidance in response to new information. To keep apprised of such developments, you can consult OSHA's website at https://www.osha.gov.

January 28, 2011

Mr. David Pryor
Director of Engineering, Global Gas Equipment
Thermadyne Operations Center
P.O. Drawer 1007
2800 Airport Road
Denton, TX 76207

Dear Mr. Pryor:

Thank you for your letter dated April 12, 2006 that was transmitted via facsimile on June 18, 2010 to the Occupational Safety and Health Administration's (OSHA's) Directorate of Enforcement Programs (DEP). This letter constitutes OSHA's interpretation only of the requirements discussed and may not be applicable to any question not delineated within your original correspondence. Please accept our apology for the delay in our response.

Your question relates to gas-shielded arc welding equipment used in construction and general industry workplaces. Your letter's scenario and question are paraphrased below, followed by our response.

Scenario: Thermadyne manufactures electric-powered gas-shielded arc welding equipment that typically uses argon or carbon dioxide, or both, as shielding gas. These gasses use either a flowmeter/regulator or a flowgauge/regulator.

Question: Must Thermadyne's gas-shielded arc welding equipment, including the flowmeter/regulator or flowgauge/regulator components, be "approved" or "listed" by a third party (for example, by a Nationally Recognized Testing Laboratory (NRTL), for use in the workplace?

Response: Yes. Because this equipment will be used for general industry work. it must comply with 29 CFR Part 1910, Subpart S, which contains such a requirement.1 The Subpart S electrical standard requires all electric-powered equipment, such as Thermadyne's electric-powered gas-shielded arc welding equipment, to be approved by a NRTL (see § 1910.303(a)2 and the definitions of "equipment" and "acceptable" in § 1910.3993). Further, Subpart S also requires employers to ensure that their electric equipment is safe, and requires them to consider that equipment's suitability for use (see §1910.303(b)(I). OSHA specified that such suitability for use can be evidenced by NRTL listing or labeling. See the note to §1910.303(b)(l)4.

Thank you for your interest in occupational safety and health. We hope you find this information helpful. This letter is intended to provide information about the standards relating to the arc welding equipment you identified. The Occupational Safety and Health Act requires employers to comply with safety and health standards promulgated by OSHA or by a state with an OSHA approved state plan. However, this letter is not itself a standard or regulation, and it creates no new legal obligations. Note that our enforcement guidance may be affected by changes to OSHA rules. In addition, from time to time we update our guidance in response to new information. To keep apprised of such developments, you can consult OSHA's website at http://www.osha.gov. If you have any further questions, please feel free to contact the Office of General Industry Enforcement at (202) 693-1850.


Thomas Galassi, Director
Directorate of Enforcement Programs

1  Electric-powered equipment used in construction must be similarly approved by a "qualified testing laboratory." 29 CFR § 1926.449. However, because third-party approval is required for this equipment for its general industry use, additional analysis under the construction standard is unnecessary. [Return to Text]

2  Section 1910.303(a) states: "Approval. The conductors and equipment required or permitted by this subpart shall be acceptable only if approved, as defined in Sec. 1910.399."   [Return to Text]

3  Section 1910.399 defines Acceptable as "An installation or equipment is acceptable to the Assistant Secretary of Labor, and approved within the meaning of this Subpart S:

(1) If it is accepted, or certified, or listed, or labeled, or otherwise determined to be safe by a nationally recognized testing laboratory recognized pursuant to § 1910.7; or
(2) With respect to an installation or equipment of a kind that no nationally recognized testing laboratory accepts, certifies, lists, labels, or determines to be safe, if it is inspected or tested by another Federal agency, or by a State, municipal, or other local authority responsible for enforcing occupational safety provisions of the National Electrical Code, and found in compliance with the provisions of the National Electrical Code as applied in this subpart; or
(3) With respect to custom-made equipment or related installations that are designed, fabricated for, and intended for use by a particular customer, if it is determined to be safe for its intended use by its manufacturer on the basis of test data which the employer keeps and makes available for inspection to the Assistant Secretary and his authorized representatives,"

Section 1910.399 defines Equipment as "A general term including ... devices, appliances ... apparatus, and the like, used ... in connection with, an electrical installation."   [Return to Text]

4  Section 19100303(b)(l) states, in part:

"Examination. Electric equipment shall be free from recognized hazards that are likely to cause death or serious physical harm to employees. Safety of equipment shall be determined using the following considerations:
(i) Suitability for installation and use in conformity with the provisions of this subpart;
NOTE TO PARAGRAPH (b)(I)(i) OF THIS SECTION: Suitability of equipment for an identified purpose may be evidenced by listing or labeling for that identified purpose.

  [Return to Text]