Answer Capsule: ANSI Z535 safety signs follow a series of six American National Standards (Z535.1 through Z535.6, plus Z535.7 added in 2024) that define signal words, colors, symbols, and formats for hazard communication. Per ANSI Z535.4, the signal word DANGER (red) means a hazard will cause death or serious injury; WARNING (orange) means it could; and CAUTION (yellow) means minor injury is possible. NOTICE (blue) covers non-injury information.
Every safety manager and electrical contractor has stood in front of a panel or piece of equipment asking the same question: which label goes here, and does it actually meet code? Pick the wrong signal word or wrong color, and you are looking at a failed inspection, a liability gap, or worse, a worker who didn't react in time because the sign blended into the background. ANSI Z535 safety signs exist to solve that problem. This set of standards gives you a precise, repeatable system for hazard communication across facilities, products, and temporary job sites. This guide breaks down every part of the ANSI Z535 series, explains the signal word hierarchy, covers the 2023 and 2024 updates, and shows you how to stay compliant on commercial and industrial jobs. Print Pro AZ supplies ANSI Z535-compliant labels, so by the time you finish reading, you will know exactly what to order.
What Is the ANSI Z535 Standard and Who Controls It?
The ANSI Z535 standard is a family of American National Standards that defines how safety signs, labels, tags, and safety messages must look and function across U.S. workplaces. The National Electrical Manufacturers Association (NEMA) administers and publishes the series. The standards committee was originally formed in 1979 and operates on a five-year revision cycle.
The core goal is consistency. Before ANSI Z535, safety signs varied widely in color, wording, and layout from facility to facility. A worker moving between job sites had no guarantee that a red sign at one location meant the same thing as a red sign at another. ANSI Z535 locked in a uniform system so anyone walking into any U.S. facility or picking up any product can interpret the warning immediately.
ANSI Z535 is technically a voluntary standard, not a federal law. However, OSHA references it directly in enforcement actions under 29 CFR 1910.145, and courts regularly use ANSI Z535 as the benchmark when judging whether a warning was adequate. That means following ANSI Z535 is your best practical protection against both OSHA citations and product liability claims.
Inspection Tip: When an OSHA inspector walks your job site, they evaluate your safety signs against ANSI Z535 specifications even if they cite you under 29 CFR 1910.145. Using the current ANSI Z535 series (Z535.1 through Z535.6, versions 2022-2023) gives you the strongest defensible position.
The series now includes seven standards after ANSI Z535.7 was published in 2024, extending the framework to digital and electronic media. Print Pro AZ stocks labels built to these current specifications.
What Are the 7 Parts of the ANSI Z535 Series?
The ANSI Z535 series divides hazard communication into seven distinct documents, each covering a specific application. Understanding which standard applies to your situation prevents mislabeling and keeps your project compliant.
| Standard | Title | Latest Version |
|---|---|---|
| ANSI Z535.1 | Safety Colors | 2023 |
| ANSI Z535.2 | Environmental and Facility Safety Signs | 2023 |
| ANSI Z535.3 | Criteria for Safety Symbols | 2023 |
| ANSI Z535.4 | Product Safety Signs and Labels | 2023 |
| ANSI Z535.5 | Safety Tags and Barricade Tapes (Temporary Hazards) | 2022 |
| ANSI Z535.6 | Product Safety Information in Manuals and Collateral Materials | 2023 |
| ANSI Z535.7 | Product Safety Information in Electronic Media | 2024 (NEW) |
Z535.1 - Safety Colors sets the precise color definitions used across the entire system. Colors are specified using Munsell notations and CIE colorimetric data so there is no guesswork. Orange has to look orange. It cannot look reddish or yellowish, because either version would cause a worker to misread the severity level.
Z535.2 - Environmental and Facility Safety Signs governs fixed signs in buildings and work areas. If you are posting a sign on a wall, a door, or a machine guard, this is your standard.
Z535.3 - Safety Symbols defines the pictograms used alongside text. Symbols reduce reaction time and help workers recognize hazards without having to read a full sentence. Per Z535.3, the Safety Alert Symbol (an exclamation point inside a triangle) must appear with DANGER, WARNING, and CAUTION signal words.
Z535.4 - Product Safety Signs and Labels applies to labels permanently attached to products, equipment, and devices. This is the standard most relevant to electrical safety labels and solar safety labels. Labels must remain legible for the life of the product under normal conditions.
Z535.5 - Safety Tags and Barricade Tapes covers temporary hazard warnings used while a hazard is being controlled or eliminated, such as lockout/tagout tags.
Z535.6 - Collateral Materials requires that safety messages in manuals and instructions use the same signal word hierarchy and design format as the signs on the product itself.
Z535.7 (2024) is the newest addition. It extends the Z535 framework to digital formats including videos, apps, e-manuals, and interactive media.
What Do the ANSI Z535 Signal Words Mean?
The five ANSI Z535 signal words are the core of the entire system. Each word corresponds to a specific level of hazard severity. Using the wrong signal word on a label is one of the most common compliance failures, and it is one of the easiest to fix once you understand the hierarchy.
| Signal Word | Background Color | Text Color | Hazard Level |
|---|---|---|---|
| DANGER | Red | White | Will cause death or serious injury |
| WARNING | Orange | Black | Could cause death or serious injury |
| CAUTION | Yellow | Black | Could cause minor or moderate injury |
| NOTICE | Blue | White (italic) | No personal injury risk; property or procedural info |
| SAFETY INSTRUCTIONS | Green | White | General safe practices and first aid directions |
DANGER is the highest severity level. Per ANSI Z535.4, use DANGER only when a hazard will result in death or serious injury if the warning is ignored. The word is printed in white on a red background. Reserve this label for situations where exposure to the hazard is essentially unavoidable without direct action. Overusing DANGER dilutes its impact. Solar disconnect labels on high-voltage DC circuits often carry DANGER headers for exactly this reason.
WARNING is for situations where death or serious injury is possible but not certain. The background is orange with black text. Most arc flash and high-voltage labels fall into this category when the hazard depends on worker actions or proximity.
CAUTION covers hazards likely to cause minor or moderate injury. Yellow background with black text. A slip hazard on a wet floor, for example, is typically a CAUTION.
NOTICE does not involve a personal injury risk. Blue background with white italic text. The Safety Alert Symbol must not be used with NOTICE. Use it for property damage warnings, operational reminders, or procedural information.
SAFETY INSTRUCTIONS uses a green background with white text. It points workers toward safe behaviors, emergency equipment locations, or first aid procedures.
Critical Rule: The Safety Alert Symbol (triangle with exclamation point) is required with DANGER, WARNING, and CAUTION. It must never appear on NOTICE signs. Mixing these up is a direct ANSI Z535.4 violation and can create confusion about the severity of a hazard.
Does ANSI Z535 Apply to Electrical and Solar Labels?
ANSI Z535 applies directly to electrical labels, solar labels, and fire safety labels when those labels are permanently attached to equipment or installed on facility walls. This is where Z535.4 and Z535.2 do most of the work.
Electrical panels, solar inverters, rapid shutdown systems, and battery storage equipment all require warning labels that communicate voltage levels, arc flash hazards, and shock risks. Per ANSI Z535.4, labels on this equipment must use the correct signal word hierarchy, the correct safety colors, and must remain legible for the life of the equipment. A label that fades, peels, or becomes unreadable fails ANSI Z535.4 regardless of whether it was correctly designed at installation.
The NEC (National Electrical Code) specifies where electrical warning labels are required, but ANSI Z535 governs how those labels must be formatted. The two standards work together. Your solar system label may be NEC 690-required, but if it uses the wrong signal word color, it does not meet ANSI Z535.4 and could fail an inspection.
Print Pro AZ produces labels for solar, electrical, and fire applications that meet both NEC requirements and ANSI Z535 formatting standards. All signal words, colors, and safety symbols are produced to spec so your crew is not guessing on the job.
Real Scenario: A solar installer attaches a CAUTION label (yellow) to a 600V DC conductor because the label shop had it in stock. The correct classification under ANSI Z535.4 for a 600V DC hazard that will cause serious injury is DANGER (red). The inspector flags it. The cost of reprinting and relabeling after the fact is several times higher than ordering the right labels from the start through Print Pro AZ.
What Changed in ANSI Z535 in 2023 and 2024?
The most significant wave of updates to the ANSI Z535 series came in 2022 and 2023, with a new standard added in 2024. If you are working from older printed references, these are the changes you need to know about.
ANSI Z535.1-2023 (Safety Colors) updated color precision specifications and continued alignment with ISO 3864-4. The 2023 version clarified tolerance ranges for each safety color to prevent off-spec printing.
ANSI Z535.2-2023 (Facility Signs) was revised to clarify its relationship with other applicable standards. Reference documents were updated to reflect currently available sources.
ANSI Z535.4-2023 (Product Safety Signs and Labels) updated specifications for design and placement of labels on products. It remains the primary standard for electrical and solar equipment labels. Minor language clarifications were made to definitions and placement requirements.
ANSI Z535.6-2023 (Collateral Materials) expanded the definitions section to include the term "risk" and made minor clarifications throughout.
ANSI Z535.7-2024 is a brand-new addition to the series. It addresses product safety information in electronic media, covering videos, apps, e-manuals, animations, and interactive platforms. This standard fills a gap that existed as product documentation moved from paper to digital formats.
One important note on OSHA: OSHA does not always reference the most current ANSI version immediately after publication. You must comply with the version of ANSI Z535 cited by the applicable OSHA regulation for your situation. When in doubt, following the most current version provides the best protection because it represents the current state of practice and is what courts will reference.
How Do You Choose the Right ANSI Z535 Label for Your Job?
Choosing the right ANSI Z535 label comes down to three questions: Where is the label going? How severe is the hazard? And how long does the label need to last?
For permanent labels on equipment and products, use Z535.4. For fixed signs on walls, columns, or doors inside a facility, use Z535.2. For temporary hazards during construction or maintenance, use Z535.5 (tags and barricade tape).
Once you have the right standard, work through the signal word selection. Ask: if someone ignores this label, what happens? Will they be seriously injured or killed (DANGER)? Could they be seriously injured or killed (WARNING)? Could they suffer a minor injury (CAUTION)? Is there no personal injury risk but a property or procedural concern (NOTICE)?
Label material matters as much as the signal word. ANSI Z535.4 requires labels to remain legible for the life of the product. Outdoor solar installations face UV exposure, heat cycling, and moisture. Indoor electrical panels see chemical exposure and abrasion. Print Pro AZ uses materials specified for each environment so your labels hold up without fading or delaminating.
Order through Print Pro AZ for commercial jobs to get pre-formatted ANSI Z535-compliant labels with the correct signal words, safety colors, and safety symbols already in place. This saves your crew from designing labels on the job and eliminates the risk of non-compliant field-made labels. See commercial ordering options here.
FAQ: ANSI Z535 Safety Sign Standards
Is ANSI Z535 legally required or just a recommendation?
ANSI Z535 is a voluntary consensus standard, but it has legal weight in practice. OSHA references ANSI Z535 in enforcement actions under 29 CFR 1910.145. Courts use ANSI Z535 as the benchmark for whether a warning was adequate in product liability cases. Many contracts and insurance policies also require ANSI Z535 compliance. Treat it as effectively mandatory.
What is the difference between ANSI Z535.2 and ANSI Z535.4?
ANSI Z535.2 governs safety signs installed in facilities and environments, such as wall-mounted signs in a plant or building. ANSI Z535.4 governs labels permanently affixed to products and equipment. If the label ships with the product or is attached to a machine, Z535.4 applies. If the sign is mounted in a room or on a structure, Z535.2 applies.
What color is a WARNING sign under ANSI Z535?
Per ANSI Z535.1 and Z535.4, a WARNING sign has an orange background with black text. Orange must be a true orange, not yellowish or reddish orange, because either variation could be confused with yellow (CAUTION) or red (DANGER), causing a worker to misjudge the hazard severity.
Can I use a NOTICE sign for an electrical hazard?
No. NOTICE is reserved for situations with no personal injury risk. Electrical hazards that can cause shock, arc flash, or electrocution require DANGER, WARNING, or CAUTION depending on the severity. Using NOTICE on a shock hazard is a direct violation of ANSI Z535.4 and could expose you to serious liability.
How often is the ANSI Z535 standard updated?
The ANSI Z535 series operates on a five-year revision cycle. The most recent full cycle produced updates in 2022 and 2023, with a new standard (Z535.7) added in 2024. Review your label stock and specifications after each revision cycle to confirm you are using current versions.
Key Takeaways and Next Steps
Three things to walk away with from this guide:
- Signal words are not interchangeable. DANGER, WARNING, and CAUTION each correspond to a specific level of hazard severity per ANSI Z535.4. Using the wrong word or color creates a compliance gap and a liability exposure.
- Know which standard applies to your application. Permanent product labels use Z535.4. Facility signs use Z535.2. Temporary tags use Z535.5. Each has its own specifications, and they work together as a system.
- Current versions matter. The series was updated in 2022 and 2023, and Z535.7 was added in 2024. Labels printed to older specifications may not reflect current standards.
Print Pro AZ supplies ANSI Z535-compliant labels for electrical, solar, and fire applications. Every label is formatted to current signal word, color, and symbol specifications so you are covered from rough-in through final inspection. For OSHA compliance resources on safety sign requirements, visit OSHA.gov.
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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.
Last Updated: 2026-09-22
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