1910.303(f): Marking and Locking Disconnects
Employers must make sure disconnecting means for motors and appliances, and for each service, feeder and branch circuit, are clearly marked to show their purpose unless it is obvious. Markings must hold up to the environment, disconnects must be able to be locked open, and equipment using series combination ratings must carry the required caution label.
Key takeaways
- 1910.303(f) is part of OSHA's general industry standards (29 CFR Part 1910, Subpart S).
- OSHA cited it 760 times in the last 3 years, in 750 inspections, with $530,235 in current penalties.
- 3 deaths are linked to inspections that cited this rule.
- Most citations: TN (163), NY (90), CT (81).
- Related part: 1910.303(f)(2) Services, feeders, and branch circuits (712 citations).
- Free 5-minute toolbox talk for your crew below.
In this article
What this rule covers
29 CFR 1910.303(f) ("Disconnecting means and circuits") is one requirement inside 1910.303 General, an OSHA general industry standard (Part 1910, Subpart S). It includes 7 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
(f) Disconnecting means and circuits — 760 citations
(1) Motors and appliances. Each disconnecting means required by this subpart for motors and appliances shall be legibly marked to indicate its purpose, unless located and arranged so the purpose is evident. Open (f)(1) 33 citations
(2) Services, feeders, and branch circuits. Each service, feeder, and branch circuit, at its disconnecting means or overcurrent device, shall be legibly marked to indicate its purpose, unless located and arranged so the purpose is evident. Open (f)(2) 712 citations
(3) Durability of markings. The markings required by paragraphs (f)(1) and (f)(2) of this section shall be of sufficient durability to withstand the environment involved. 6 citations
(4) Capable of accepting a lock. Disconnecting means required by this subpart shall be capable of being locked in the open position. 5 citations
(5) Marking for series combination ratings. 1 citations
(i) Where circuit breakers or fuses are applied in compliance with the series combination ratings marked on the equipment by the manufacturer, the equipment enclosures shall be legibly marked in the field to indicate that the equipment has been applied with a series combination rating. 1 citations
(ii) The marking required by paragraph (f)(5)(i) of this section shall be readily visible and shall state “Caution—Series Combination System Rated __ Amperes. Identified Replacement Component Required.”
Source: eCFR, text current as of 2026-10-15. Read all of 1910.303.
Injuries linked to this rule
3 deaths are linked to inspections where OSHA cited 1910.303(f).
At 12:11 p.m. on August 20, 2024, an employee working for a food manufacturer was installing a lighting fixture on an energized system. The employee contacteda live wire and was electrocuted. The employee died as a result of his injuries.
Full case list with employer, penalty, filters and download is part of OSHA Data (Purple Belt).
Unlock with Purple BeltWhere and how often it was cited
| Year | Citations |
|---|---|
| 2023 | 58 |
| 2024 | 258 |
| 2025 | 254 |
| 2026 | 190 |
Top states: TN (163), NY (90), CT (81), VA (52), IL (39)
Largest penalties
| Employer | Location | Penalty for this rule |
|---|---|---|
| GABRIEL CARE, INC. | FALL RIVER, MA | $16,550 |
| PERDUE FOODS LLC | BRIDGEWATER, VA | $13,075 |
| WHITE CAP | SAINT CHARLES, MO | $12,676 |
| BIG TEX TRAILER MANUFACTURING, LLC | BATAVIA, OH | $11,585 |
| VILLAGE FARMS, LP. / MARFA 1 | MARFA, TX | $11,250 |
Free toolbox talk
A 5-minute crew talk on 1910.303(f), plus alerts when this rule changes. Free.
OSHA interpretation letters
- Relevance of NFPA 70E industry consensus standard to OSHA requirements; whether OSHA requirements apply to owners. (2003-07-25)
Related parts of this rule
- 1910.303(f)(2) Services, feeders, and branch circuits 712 citations
- 1910.303(f)(1) Motors and appliances 33 citations
Get your crew competent
Trainers on Black Belt Safety: Marc Harvey, Dana Reyes
Trainers and suppliers: feature your business on this rule for $25/month.
Frequently asked questions
Does every disconnect need a label?
Yes, unless it is located and arranged so its purpose is evident.
Must a disconnect be lockable?
Yes. Disconnecting means required by this subpart must be capable of being locked in the open position.
How durable must the markings be?
Durable enough to withstand the environment they are in.
About this page
Sources
- 29 CFR 1910.303 (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 2026-10-20
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.