Arc Flash Label Review: 5-Year Rule and Relabel Triggers

Last Updated: 2026-10-09

Answer Capsule: NFPA 70E-2024 Section 130.5(H) requires the data behind an arc flash label to be reviewed at intervals not to exceed 5 years. It must also be updated whenever a change in the electrical distribution system could affect the results. That means a new label when the review changes any value, or when breakers, sources, or transformers change sooner.

"Do we really need to redo the arc flash study every 5 years?" That is the question facility managers ask Print Pro AZ. It usually comes up when they call for replacement labels and notice the assessment date reads 2019. The short answer is that the review is required and the full study is not always. But the label almost always changes. Miss the review and every label in the building carries numbers nobody can vouch for.

This post explains the 5-year rule in NFPA 70E-2024 Section 130.5(H). It covers the changes that force a new label before the 5 years are up, and how to run the review so your labels stay honest. Brent Hanke, founder of Print Pro AZ, has printed relabel sets for facilities at every point in that cycle. The triggers below come from the Print Pro AZ field guide.

Do You Have to Redo the Arc Flash Study Every 5 Years?

You have to review it at intervals not to exceed 5 years, and you have to update it whenever a change could affect the results. NFPA 70E-2024 Section 130.5(H) requires the method of calculating and the data supporting the label to be documented. That data must be reviewed at intervals not to exceed 5 years. It must be updated when a change in the electrical distribution system could affect the results.

Review is not the same as re-run. A review checks whether the inputs to the old study are still true. If nothing changed, the engineer documents that and the numbers stand. If anything changed, the affected equipment gets recalculated. In practice, five years is a long time in a building, and most reviews find something.

The risk assessment itself comes from NFPA 70E 130.5, and the label rules for the workplace sit in 130.5(H). On the installation side, NEC 110.16 requires the date the assessment was completed on the label. Our NFPA 70E 2024 arc flash label requirements guide covers both in full. Confirm which NEC edition your AHJ enforces, since the 2026 edition removed the amp threshold.

What Does a 5-Year Arc Flash Review Actually Check?

A 5-year review checks whether the one-line diagram still matches the building and whether any input to the incident energy calculation changed. The engineer compares the study inputs against the field, one item at a time:

• The one-line diagram. Every source, transformer, feeder, and piece of gear in the study still exists, and nothing new was added.
• Protective device settings. Breaker trip settings, fuse types, and relay settings match what the study assumed.
• Available fault current. The utility's number has not changed, and no new source was tied in.
• Transformers. Same kVA, same impedance, same configuration.
• Equipment condition. The gear is installed and maintained as the study assumed. Poor maintenance disqualifies the PPE category method under NFPA 70E.
• The calculation standard. IEEE 1584-2018 replaced the 2002 model. A study still based on 1584-2002 should be re-run.

Your takeaway: Give the engineer a clean list of everything that changed since the last study. The walk-down is where the review earns its cost.

Which Changes Force a New Arc Flash Label Before 5 Years?

Any change in the electrical distribution system that could affect the results forces an update. The Print Pro AZ field guide lists the three that show up most often on Arizona jobs.

Relabel trigger	Why it changes the label	What to send the engineer
Protective device, fuse, or trip-setting change	Clearing time drives incident energy. A different breaker or setting changes the number and the boundary.	Device make, model, settings, and the equipment it protects
New utility source, generator, battery, or tie	A new source changes available fault current. Batteries and generators add DC or alternate paths the study never saw.	One-line showing the new source and its ratings
Transformer kVA, impedance, or configuration change	The transformer sets the fault current on its secondary. Change it and every label downstream may change.	Nameplate data for the new transformer
Study still based on IEEE 1584-2002	The 2018 edition added electrode configuration, enclosure size correction, and a 2 second clearing time convention. It removed the old exemption for systems below 240 V fed by a single transformer under 125 kVA.	The original study report and date

Here is a call Print Pro AZ gets every month. A facility added a standby generator two years after the study. The transfer switch went in, the inspection passed, and nobody told the arc flash engineer. Every label on the emergency side still shows values from a source that no longer exists alone. The date on those labels looks fine. The numbers are not.

Field note: A fresh assessment date does not protect you if the system changed after it. The date tells the inspector when the clock started. It does not tell them what happened since.

Why Does the Date on the Label Change Even When the Numbers Do Not?

The date changes because NEC 110.16 requires the date the assessment was completed, and a review that confirms the data is a completed assessment. A review that changes nothing still produces a new completion date, and that date belongs on the label. The old date would tell the next inspector that the 5-year clock ran out.

That is why a review almost always means a relabel, even in a building where nothing moved. The arc flash assessment date requirement post covers what counts as a valid date and why the print date does not. Confirm the approach with your engineer and AHJ, since some owners record the review in the program document as well.

A missing or stale assessment date is one of the five inspection failures in the Print Pro AZ field guide. It is also the easiest one to fix, because the fix is a label.

How Do You Run the Review Without Starting From Scratch?

You pull the last study, walk the one-line against the building, hand the engineer a change list, and print the new set from the updated table. Here are the steps:

1. Pull the last study report and the label data table it produced. If you cannot find them, that is your first finding.
2. Walk the one-line with someone who knows the building. Mark every device, source, and transformer that changed.
3. Send the change list to the engineer. Ask whether the old study used IEEE 1584-2002 or 2018.
4. Get back an updated table with a new assessment completion date on every row.
5. Send the table to Print Pro AZ as a PDF, Excel, or CSV file. The full set ships the same week on UV-rated polyester or .048 aluminum.
6. Replace every label, not just the ones whose numbers moved, because the date moved on all of them.

Why the whole set: Replacing only the changed labels leaves two dates on the same site. The next inspector has to guess which one is current. A full set from one table takes that guess away. Browse the arc flash label collection to see the sizes and materials that ship with a relabel.

Frequently Asked Questions

Is an arc flash study required every 5 years by OSHA?

OSHA does not set an interval. It enforces arc flash protection through the General Duty Clause, and its 2006 letter of interpretation describes NFPA 70E as a widely accepted approach. NFPA 70E 130.5(H) is where the 5-year review interval comes from.

Does changing a breaker really change the arc flash label?

Yes, it can. The breaker's clearing time is one of the main inputs to incident energy. A slower or faster device changes the cal/cm2 value and the arc flash boundary on the label. Send the new device data to the engineer before the label is reprinted.

What if the study is older than 5 years and nothing has changed?

You still owe the review. NFPA 70E 130.5(H) sets the interval at not to exceed 5 years regardless of changes. The engineer documents the review, issues a new completion date, and the labels get that date.

Does a study based on IEEE 1584-2002 need to be redone?

Yes. The 2018 edition replaced the 2002 model and removed the old exemption for low-voltage systems fed by small transformers. Labels printed from a 2002-based study may show incident energy values the current method would not produce. Ask the engineer for a re-run under IEEE 1584-2018.

Conclusion

Three things to remember. First, NFPA 70E 130.5(H) requires a review of the label data at intervals not to exceed 5 years, and an update whenever the system changes. Second, breaker changes, new sources, transformer changes, and a 2002-based study all force an update before the 5 years run out. Third, a review produces a new assessment date, and that date goes on every label.

Keeping the review on schedule keeps every label in the building honest. That is what gets your crew dressed right and gets the inspector out the door. Print Pro AZ turns the updated table into a full set with same-week shipping.

Have a facility due for review? Send us your plan sets and the study table. Questions? Call Brent: (602) 649-5305.

Sources

• NFPA 70E, Standard for Electrical Safety in the Workplace
• OSHA Standard Interpretation, November 14, 2006
• IEEE 1584-2018, Guide for Performing Arc-Flash Hazard Calculations

Brent Hanke | Print Pro AZ | (602) 649-5305 | b.hanke@printproaz.com

Brent Hanke is the founder of Print Pro AZ, supplying NEC-compliant labels to contractors across the country.