---
title: "What arc welding and cutting safety requirements does 29 CFR 1926.351 set for construction sites regarding shielding and grounding return circuits? Answer in under 100 words. Cite only eCFR (www.ecfr.gov) sources."
canonical: https://www.m-i-n-d.ai/minds/welding/arc-welding-cutting-safety-requirements-29-cfr-1926-351-set-construction-sites
jurisdiction: "US Federal · OSHA Construction (29 CFR Part 1926)"
last_verified: 2026-08-26
license: CC BY 4.0 — https://creativecommons.org/licenses/by/4.0/
attribution: "Source: MIND (m-i-n-d.ai)"
---

# What arc welding and cutting safety requirements does 29 CFR 1926.351 set for construction sites regarding shielding and grounding return circuits? Answer in under 100 words. Cite only eCFR (www.ecfr.gov) sources.

For construction sites, 29 CFR 1926.351 requires that, whenever practicable, all arc welding and cutting operations be shielded by noncombustible or flameproof screens protecting nearby employees from the direct rays of the arc. Ground return cables must have a safe current-carrying capacity equal to or exceeding the specified maximum output of the welding units they serve. Pipelines containing gases or flammable liquids, and electrical conduits, may never be used as a ground return. Structures used as ground-return circuits must have proper electrical contact at all joints—any arcing, sparks, or heat disqualifies them—and joints must be bonded, with periodic inspections.

## Details / How it works

**Shielding:** Under § 1926.351(e), whenever practicable, all arc welding and cutting operations must be shielded by noncombustible or flameproof screens that protect employees and other persons working in the vicinity from the direct rays of the arc.

**Ground returns:** A ground return cable must have a safe current-carrying capacity equal to or exceeding the specified maximum output of the arc welding or cutting unit it services. A structure or pipeline may serve as a ground-return circuit only if the required electrical contact exists at all joints; any generation of arc, sparks, or heat rejects the structure as a ground circuit. When a structure or pipeline is continuously employed as a ground return, all joints must be bonded and periodic inspections conducted.

## Numbers & thresholds

| Requirement | Threshold |
|---|---|
| Ground return cable capacity | Equal to or exceeding the specified maximum output of the unit it services |
| Shared ground return (multiple units) | Equal to or exceeding the total specified maximum outputs of all units served |
| Joint condition on structure/pipeline circuits | Any arc, sparks, or heat at any point = rejection as a ground circuit |

## Exceptions & edge cases

- Pipelines containing gases or flammable liquids, and conduits containing electrical circuits, are prohibited as ground returns.
- For welding on natural gas pipelines, the technical portions of U.S. Department of Transportation regulations at 49 CFR part 192 apply.
- Where a structure or pipeline is continuously used as a ground return, bonding of joints plus periodic inspections ensure no condition of electrolysis or fire hazard arises.
- Shielding is required "whenever practicable," applying to protection of both workers and other persons near the operation.

## Sources

- [1] U.S. National Archives, Electronic Code of Federal Regulations — 29 CFR 1926.351 — Arc welding and cutting · https://www.ecfr.gov/current/title-29/section-1926.351 · as of 2026-08-26