1910.334(c): Safe Use of Electrical Test Instruments
Only qualified persons may do testing work on electric circuits or equipment. Test instruments, leads, cables, cords, probes and connectors must be visually inspected for defects and damage before use, removed from service if damaged until repaired and tested, and rated for the circuits and environment where they are used.
Key takeaways
- 1910.334(c) is part of OSHA's general industry standards (29 CFR Part 1910, Subpart S).
- OSHA cited it 14 times in the last 3 years, in 11 inspections, with $72,065 in current penalties.
- Most citations: IA (4), NJ (2), OH (1).
- Related part: 1910.334(c)(1) Use (6 citations).
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In this article
What this rule covers
29 CFR 1910.334(c) ("Test instruments and equipment") is one requirement inside 1910.334 Use of equipment, an OSHA general industry standard (Part 1910, Subpart S). It includes 3 sub-paragraphs. The official text below is copied word for word from the Electronic Code of Federal Regulations (eCFR). The numbers, injury cases and training on this page show how OSHA enforces it on real job sites.
Official text
(c) Test instruments and equipment — 14 citations
(1) Use. Only qualified persons may perform testing work on electric circuits or equipment. Open (c)(1) 6 citations
(2) Visual inspection. Test instruments and equipment and all associated test leads, cables, power cords, probes, and connectors shall be visually inspected for external defects and damage before the equipment is used. If there is a defect or evidence of damage that might expose an employee to injury, the defective or damaged item shall be removed from service, and no employee may use it until repairs and tests necessary to render the equipment safe have been made. 5 citations
(3) Rating of equipment. Test instruments and equipment and their accessories shall be rated for the circuits and equipment to which they will be connected and shall be designed for the environment in which they will be used. 3 citations
Source: eCFR, text current as of 2026-10-15. Read all of 1910.334.
Export the list: 11 inspections cited 1910.334(c) in the last 3 years, with employer, location, penalty and date.
Purple Belt, $59/moWhere and how often it was cited
| Year | Citations |
|---|---|
| 2024 | 2 |
| 2025 | 5 |
| 2026 | 7 |
Top states: IA (4), NJ (2), OH (1), TN (1), GA (1)
Largest penalties
| Employer | Location | Penalty for this rule |
|---|---|---|
| A09CS00000TJEZVAAY - MIDAMERICAN ENERGY COMPANY | SALIX, IA | $18,090 |
| RESA POWER, LLC | LEMONT, IL | $16,550 |
| RAPID PUMP & METER CO., INC. | NEWARK, NJ | $12,000 |
| LOS LUNAS, VILLAGE OF, PARKS & RECREATION DEPARTMENT | LOS LUNAS, NM | $11,588 |
| HOUSE OF CHEATHAM LLC | STONE MOUNTAIN, GA | $6,453 |
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A 5-minute crew talk on 1910.334(c), plus alerts when this rule changes. Free.
OSHA interpretation letters
None exist. OSHA has not published a letter of interpretation for 1910.334(c).
Related parts of this rule
- 1910.334(c)(1) Use 6 citations
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Frequently asked questions
Who can test electric circuits?
Only qualified persons may perform testing work on electric circuits or equipment.
What do I check before using a meter?
Visually inspect the instrument and all test leads, cables, power cords, probes and connectors for external defects and damage.
Can I use any meter on any circuit?
No. Test instruments and accessories must be rated for the circuits and equipment they connect to and designed for the environment where they are used.
About this page
Sources
- 29 CFR 1910.334 (eCFR), text current as of 2026-10-15
- U.S. Department of Labor enforcement data: OSHA inspections, citations and accident records, copied nightly; data as of 2026-11-01
3-year window. Federal OSHA only; state-plan rules are not counted. Plain-language text is a summary, not legal advice; the official text controls. Black Belt Safety is not part of OSHA or the Department of Labor.