OSHA Danger Sign Requirements: ANSI Z535 and HazCom 2012

This article is part of the Print Pro AZ OSHA and ANSI safety sign series. Start with the pillar guide: ANSI Z535 Safety Signs: Complete Standards Guide.

Per OSHA 29 CFR 1910.145 and ANSI Z535.2, a DANGER sign must use a safety red header panel, white signal word "DANGER" in white or contrasting text, and convey a hazard that will cause death or serious injury if not avoided. ANSI Z535.2 governs environmental and facility signs. ANSI Z535.4 governs product labels. HazCom 2012 aligns chemical labels with GHS standards, which use the same DANGER/WARNING signal words.

Someone on your job site cannot read the chemical drum label fast enough. They pick the wrong container. They open a valve in front of the wrong equipment. The sign on the wall said something, but it did not stop them. You know why: the sign was wrong. Or it was missing. Or no one could tell if it meant "this will kill you" or "watch your step."

DANGER signs exist for one reason -- to communicate immediate, life-threatening hazards clearly and fast. ANSI Z535.2 defines exactly what a DANGER sign must look like, what it must say, and where it must go. OSHA 29 CFR 1910.145 backs it up with enforcement authority.

This guide covers both standards in detail, explains how HazCom 2012 (GHS) fits into the picture, and shows you how Print Pro AZ supplies compliant safety signs for facilities that cannot afford to get this wrong.

What Is ANSI Z535?

ANSI Z535 is a family of standards published by the American National Standards Institute that govern the design, application, and use of safety signs, labels, and tags. It is not a single document but a suite:

Standard	Scope
ANSI Z535.1	Safety colors (specific Pantone and CMYK values for each signal word color)
ANSI Z535.2	Environmental and facility safety signs (wall signs, floor signs, posted notices)
ANSI Z535.3	Safety symbols (graphical symbol design criteria)
ANSI Z535.4	Product safety signs and labels (labels applied to equipment and products)
ANSI Z535.5	Tags and barricade tapes
ANSI Z535.6	Safety messages in product manuals and instructions

For most contractors, electricians, and facility managers, the two relevant standards are Z535.2 (the sign on the wall) and Z535.4 (the label on the product or equipment).

ANSI Z535 does not carry the force of federal law on its own. OSHA adopts it by reference and enforces equivalent requirements through 29 CFR 1910.145. Where 1910.145 is silent on a design detail (it mostly covers format concepts), ANSI Z535 fills the gap and defines the accepted industry standard.

What Does OSHA 29 CFR 1910.145 Require?

OSHA's safety signs standard, 29 CFR 1910.145, establishes the basic framework:

1910.145(a): Scope -- applies to all accident prevention signs used in construction, demolition, alterations, and maintenance of buildings and other structures
1910.145(b): Definitions -- signal words (DANGER, CAUTION, SAFETY INSTRUCTION), colors, and classifications
1910.145(c): Classification -- three categories: danger, caution, and safety instruction
1910.145(d): Specifications -- format, color, and construction requirements for each category
1910.145(e): Use of safety signs -- when each type must be applied
1910.145(f): Tags -- when tags apply vs. signs

The standard defines the three signal word categories:

DANGER: Used only for immediate hazards that will result in death or serious injury
CAUTION: Used for potentially hazardous situations that may result in minor or moderate injury, or property damage
SAFETY INSTRUCTION: Used for general instructions and suggestions on safety not related to a specific hazard

Note: OSHA 1910.145 uses DANGER and CAUTION. ANSI Z535 uses DANGER, WARNING, and CAUTION, with WARNING inserted between the other two for hazards that could (but may not always) cause death or serious injury. ANSI Z535 is the more complete system; OSHA 1910.145 is older and was not fully updated when ANSI Z535 was revised.

DANGER Sign Design Requirements: ANSI Z535.2

Per ANSI Z535.2, a DANGER sign must meet these design specifications:

Color:

Header panel: Safety red (ANSI Z535.1 defines the exact color values; Pantone 186 C is the common match)
Signal word "DANGER": White text on the red header
Message panel: White background preferred; black text for the hazard description

Safety Alert Symbol: A DANGER sign that warns about personal injury must include the Safety Alert Symbol -- an exclamation point inside an equilateral triangle. The symbol appears in the header panel alongside the signal word. It is required for personal injury hazards. It is omitted for property damage-only or non-injury hazards.

Panel layout (standard format):

Top panel: Red background, Safety Alert Symbol (if personal injury), white "DANGER" text
Middle panel (optional): Pictogram illustrating the hazard
Bottom panel: White or light background, black text message describing the hazard, the consequence of not heeding it, and instructions to avoid it

Text content requirements: A compliant DANGER message should answer three questions:

What is the hazard?
What can happen if you ignore it?
What should you do?

Example: "DANGER -- HIGH VOLTAGE -- Contact will cause death or serious injury -- Turn off and lock out power before servicing."

Inspection Tip: A sign that says "DANGER -- HIGH VOLTAGE" with nothing else is incomplete. It tells workers what the hazard is but does not state the consequence or the avoidance action. Per ANSI Z535.2, complete messaging requires all three elements. AHJs and OSHA compliance officers increasingly look for complete messaging, especially in facilities with high-severity hazards.

ANSI Z535.4 -- Product Safety Signs and Labels

When the sign is applied directly to a product -- a piece of equipment, a machine, a chemical drum -- ANSI Z535.4 governs instead of Z535.2. The signal word definitions and color requirements are identical. The differences lie in:

Durability: Product labels must withstand the product's operating environment throughout its service life. This is where label material matters -- outdoor equipment, chemical exposure, heat cycles, and UV light all affect label longevity.
Size and placement: Labels on equipment must be large enough to be read from the normal working position, and placed where the worker can see it before encountering the hazard.
Persistence: The label should be applied so it cannot be easily removed or obscured by routine maintenance.

This is where UL 969 certification becomes relevant. A UL 969-certified label construction has been tested for adhesion, chemical resistance, UV exposure, and temperature extremes. For permanent safety labels on equipment, UL 969 PGDQ2 certification is the standard of proof that the label will survive the environment it is installed in.

How HazCom 2012 (GHS) Relates to Danger Signs

OSHA's Hazard Communication Standard (HazCom 2012, 29 CFR 1910.1200) aligned U.S. chemical labeling with the UN's Globally Harmonized System of Classification and Labelling of Chemicals (GHS). GHS uses the same signal words as ANSI Z535 -- DANGER and WARNING -- with identical severity meanings:

DANGER: More severe hazard categories (higher risk of death, serious injury, or serious health effects)
WARNING: Less severe hazard categories

HazCom 2012 labels (now being updated to align with GHS 7th edition under OSHA's 2024 final rule, with key deadlines in 2026) must include:

Product identifier
Signal word (DANGER or WARNING)
Hazard statement(s)
Pictogram(s) from the GHS set
Precautionary statement(s)
Supplier name, address, and phone number

HazCom labels use a different format than facility safety signs -- they are container labels, not wall signs. But the underlying signal word framework is consistent. A worker who understands that DANGER means "this will hurt you badly or kill you" reads that same signal word on a chemical drum label and gets the same message.

Critical Rule: Facility danger signs (ANSI Z535.2) and GHS container labels (HazCom 1910.1200) serve different purposes. Both use DANGER as their highest-severity signal word. Do not replace a required GHS container label with an ANSI facility sign -- they are not interchangeable.

Where Must Danger Signs Be Posted?

OSHA 1910.145(e) requires danger signs in locations where an immediate hazard exists. ANSI Z535.2 provides placement guidance:

At the point of hazard -- close enough to the hazard that the sign is visible before a worker reaches the danger zone
At entrances to hazardous areas -- when the hazard is present throughout a room or area
At controlled access points -- before workers pass the boundary of a restricted zone
Visible from normal approach directions -- a sign facing the wrong way is a non-sign

Specific situations where DANGER signs are commonly required:

High-voltage electrical equipment (per NEC and OSHA)
Confined spaces with immediately dangerous to life and health (IDLH) atmospheres
Areas with energized equipment rated above 50 volts (approaching limits per NFPA 70E)
Hazardous chemical storage rooms
Active fall hazards above threshold heights

Print Pro AZ stocks customizable OSHA DANGER labels through our electrician labels collection, available in six standard sizes from 1.5x3" to 5x10", printed on UV-resistant vinyl. For facilities needing custom DANGER sign text, our custom label ordering lets you specify exact hazard messaging.

FAQ: OSHA Danger Sign Requirements

When should I use DANGER vs. WARNING vs. CAUTION? DANGER means the hazard will cause death or serious injury if not avoided. WARNING means it could cause death or serious injury. CAUTION means it may cause minor or moderate injury or property damage. If a worker ignores the sign and the worst outcome is a minor cut or equipment damage, it is a CAUTION. If the worst outcome is death, it is a DANGER. When in doubt, use the higher signal word -- under-communicating hazard severity creates liability.

Are ANSI Z535 signs required by OSHA? Not directly by name. OSHA 29 CFR 1910.145 sets the requirements; ANSI Z535 defines the accepted design standard. OSHA compliance officers treat Z535-compliant signs as meeting 1910.145. Signs that deviate from Z535 design requirements may be cited if they fail to clearly communicate the hazard as required by 1910.145(d).

Does the Safety Alert Symbol have to appear on every danger sign? No. The Safety Alert Symbol (exclamation point in a triangle) is required on DANGER, WARNING, and CAUTION signs that warn about personal injury hazards. It is omitted on signs warning about property damage or non-injury hazards only. In practice, most danger signs in electrical and chemical environments are personal injury hazards and include the symbol.

Can I print my own OSHA danger signs? Yes, if they meet ANSI Z535.2 or Z535.4 design requirements and are made of material durable enough for the environment. A laser-printed sheet of paper taped to a panel does not meet durability requirements for outdoor or industrial environments. Use UV-resistant vinyl labels or rigid sign stock appropriate for the installation location.

What is the difference between ANSI Z535.2 and ANSI Z535.4? Z535.2 governs facility signs -- signs posted on walls, floors, barriers, and in spaces. Z535.4 governs product safety labels -- labels applied directly to equipment, machinery, or containers. Both use the same signal word definitions and color standards, but Z535.4 has more specific requirements for label durability, placement on equipment, and visibility at normal working positions.

Three Takeaways and Next Steps

DANGER signs under ANSI Z535.2 require a safety red header, white signal word, and complete hazard messaging covering what the hazard is, what happens if ignored, and what to do about it.
OSHA 29 CFR 1910.145 is the enforcement mechanism; ANSI Z535 is the design standard. Using Z535-compliant signs is the accepted way to demonstrate 1910.145 compliance.
HazCom 2012 (GHS) uses the same DANGER/WARNING framework for chemical labels -- the systems are aligned, not interchangeable.

Shop our customizable OSHA DANGER labels built on UV-resistant vinyl for indoor and outdoor environments. Browse the electrician labels collection or call Brent: (602) 649-5305

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: 2026-09-23