OSHA electrical panel labeling requirements
OSHA requires that every circuit breaker and disconnect be legibly marked to show what it controls, unless that is obvious from where it is, and that the marking stand up to the environment. Every disconnect must also be able to take a lock. The NEC, which OSHA’s rule is drawn from, adds the detail: a circuit directory on the face or inside the door of every panelboard, with each circuit identified by a clear, evident and specific purpose, spare positions marked as spare, and no descriptions that depend on who happens to occupy a room. Panels in other than dwellings are also marked with where their power comes from, and panels likely to be worked on while energized carry an arc flash warning label.
Brady S3100 sign and label printerPrints arc flash, panel and circuit labels up to 4 inches wide; walk-up touchscreenWhy does OSHA care what is written on a breaker? Two reasons. In an emergency, the person at the panel has to find the right breaker now, not after flipping six. And in lockout, the authorized employee has to be sure the breaker they locked is the one feeding the machine they are about to put their hands in; a mislabeled or blank breaker is how a locked-out machine turns out to be live. The marking rule and the lock-capable rule sit side by side in 1910.303(f) for that reason.
What does OSHA require on a panel?
From 1910.303, which OSHA adopted from the NEC, and the electrical work-practice rules in Subpart S.
What does the NEC require in the circuit directory?
The National Electrical Code is the installation standard that OSHA’s 1910.303 was taken from, and it is what the electrical inspector enforces on new work. NEC 408.4(A) requires every circuit and every circuit modification to be legibly identified as to its clear, evident and specific purpose or use, with enough detail to tell each circuit from all the others. Spare positions are marked as spare, and the identification may not be based on a transient condition of occupancy, so “Jim’s office” fails and “Office 204, north wall receptacles” passes. The directory goes on the face or inside the door of a panelboard, and on the switch for a switchboard or switchgear. NEC 408.4(B) adds that in other than one- and two-family dwellings, the panel is permanently marked with the source that supplies it, such as the upstream panel or transformer.
NFPA 70 (NEC) 2023, 408.4(A) Circuit Directory or Circuit Identification, and 408.4(B) Source of Supply, cited at section level.NEC 110.22(A) carries the same purpose-marking rule as OSHA for each disconnecting means, and in other than dwellings requires the marking to include the identification and location of the circuit source that supplies the disconnect unless that is evident. The marking must be of sufficient durability to withstand the environment. Field-applied hazard markings under 110.21(B) must use signal words per ANSI Z535.4, be permanently affixed, and may not be handwritten.
NEC 2023, 110.22(A) Identification of Disconnecting Means (text as published in code commentary); 110.21(B) Field-Applied Hazard Markings, cited at section level.What is the arc flash label on a panel?
NEC 110.16(A) requires switchboards, switchgear, panelboards, industrial control panels, meter socket enclosures and motor control centers in other than dwellings that are likely to require examination, adjustment, servicing or maintenance while energized to be field-marked to warn qualified persons of potential arc flash hazards. The marking must be clearly visible to a person before they work on the equipment. NEC 110.16(B) adds a label for service equipment rated 1,200 amperes or more giving the nominal system voltage, available fault current, the clearing time of the overcurrent device and the date the calculation was made. NFPA 70E, the workplace electrical safety standard, specifies what the full arc flash label carries: nominal system voltage, the arc flash boundary, and the incident energy at a working distance or the PPE category, from an incident energy analysis the employer has done. The label is the output of that analysis; a printer makes the label, it does not supply the numbers.
NEC 2023, 110.16(A) and (B) Arc-Flash Hazard Warning; NFPA 70E, Article 130, equipment labeling; both cited at section level. OSHA enforces the underlying duty through 1910.335(b)(1) and 1910.132(d) hazard assessment.What else goes on or around the panel?
- Working space kept clear: the depth in Table S-1 in front of the panel, at least 30 inches wide or the width of the equipment, the door able to open 90 degrees, and no storage in that space.
- Illumination of the working space for indoor service equipment, switchboards, panelboards and motor control centers.
- Lockout: a breaker lockout or a panel-door lockout that holds the disconnect open, and the tag naming the worker, per 1910.147 and 1910.333(b)(2).
Label makers, tapes, wire labels and panel lockouts
18 items · prices livePrinters and label stocks are as described by the manufacturer; outdoor life and temperature ratings are on each product page. Arc flash label values come from the employer’s incident energy analysis. Free shipping on orders over $199.
Pre-printed arc flash and voltage warning labels, panel schedule cards and larger lockout kits are quoted on request: call (925) 215-7337.
Questions people ask
Does OSHA require electrical panels to be labeled?
Yes. 1910.303(f)(2) requires each service, feeder and branch circuit to be legibly marked at its breaker or disconnect to show its purpose, unless the purpose is evident, and (f)(3) requires the marking to be durable.
What does the NEC require in a panel directory?
Every circuit identified by its clear, evident and specific purpose, in enough detail to tell it from every other circuit, spares marked as spare, nothing based on a transient occupant, on the face or inside the door. (NEC 408.4(A).)
Can panel labels be handwritten?
OSHA requires only that they be legible and durable. The NEC prohibits handwriting for field-applied hazard markings under 110.21(B); circuit directories are commonly printed or typed because a pencil directory does not stay legible.
What is the arc flash label requirement?
NEC 110.16 requires a field-applied arc flash warning on panels and similar equipment likely to be worked on while energized; NFPA 70E specifies the label content from an incident energy analysis.
How much clearance is required in front of a panel?
The working space depth in 1910.303(g)(1) Table S-1 for the voltage and conditions, at least 30 inches wide, with the door able to open 90 degrees and nothing stored in it.
Does a panel have to be lockable?
Each disconnecting means required by Subpart S must be capable of being locked in the open position. (1910.303(f)(4).) A breaker lockout or panel lockout device supplies the lock point on a breaker that has none.
Does a panel have to say where its power comes from?
Under the NEC, yes, in other than one- and two-family dwellings: 408.4(B) requires the source of supply to be marked on the panel, and 110.22(A) requires it on the disconnect.
Standards and ratings on this page are as published in the documents named and by the manufacturers named. The employer’s hazard assessment and written program decide what applies at a given workplace. Verify a rating on the product and its spec sheet before use.