What is the difference between DANGER and WARNING on a safety sign?

Severity and probability. DANGER (white text on safety red) is reserved for hazards that WILL result in death or serious injury if not avoided — high voltage bus, confined space with fatal atmosphere. WARNING (black text on safety orange) marks hazards that COULD result in death or serious injury. CAUTION (black on safety yellow) covers hazards that could cause minor or moderate injury. Overusing DANGER dilutes it; ANSI Z535.5 explicitly discourages assigning DANGER to anything below will-kill severity.

Does OSHA require ANSI Z535 formatted signs?

OSHA 29 CFR 1910.145 sets the baseline for accident prevention signs and tags, and since its 2013 update OSHA recognizes the ANSI Z535-2011 series as an acceptable — and in practice preferred — means of compliance. New installations overwhelmingly follow Z535 layouts because they also satisfy the older OSHA specifications.

What does the NOTICE header mean?

NOTICE (white italic text on safety blue) is for information that is important but NOT hazard-related: security policies, hygiene rules, equipment operating instructions. If personal injury is possible, NOTICE is the wrong header — that is a CAUTION or above.

Can I print ANSI Z535 header colors on a thermal transfer printer?

Yes, two ways: print black legends onto pre-printed header label stock (DANGER/WARNING/CAUTION headers already on the liner), or use a multi-color capable sign printer such as the Brady i5300 / BBP37 class, which prints the red, orange, or yellow header panel and the message in one pass on B-595 or B-7569 vinyl.

Home GuidesANSI Z535 Colors & Signal Words

Safety Signage Standard

ANSI Z535 Safety Colors & Signal Words: DANGER vs. WARNING vs. CAUTION

The header color on a safety label is not a design choice — it is a severity rating. ANSI Z535 assigns each signal word a precise color, a precise meaning, and a precise misuse. Get the hierarchy wrong in either direction and you fail differently: over-labeling breeds alarm fatigue, under-labeling breeds citations. Here is the full severity logic, the five-part standard series, and how to produce compliant headers in-house.

1. The Signal Word Severity Ladder

Each header below is rendered in the screen approximation of its ANSI Z535.1 safety color. The severity question is always the same: if the hazard is not avoided, what is the probable outcome?

⚠ DANGER

Severity Threshold

WILL result in death or serious injury

Correct Use

Immediately hazardous situations: exposed energized conductors above 600 V, fatal atmospheres, crush zones with no guarding.

Common Misuse

General electrical rooms, hot surfaces, forklift traffic — these belong under WARNING or CAUTION.

⚠ WARNING

Severity Threshold

COULD result in death or serious injury

Correct Use

Arc flash labels, machine entanglement points, stored-energy hazards. The default header for serious industrial hazards.

Common Misuse

Property-damage-only risks. If nobody can get hurt, it is a NOTICE.

⚠ CAUTION

Severity Threshold

Could result in minor or moderate injury

Correct Use

Pinch points, hot-to-touch surfaces, slip hazards, PPE reminders tied to lower-severity outcomes.

Common Misuse

Life-threatening hazards. Under-labeling severity is the failure auditors flag hardest.

NOTICE

Severity Threshold

No injury potential — practices & policies

Correct Use

Security rules, hygiene procedures, operational instructions — “Authorized personnel only”, “Keep door closed”.

Common Misuse

Anything where a person can be hurt. NOTICE never announces a hazard.

SAFETY INSTRUCTIONS

Severity Threshold

Positive safety information

Correct Use

Egress routes, first aid and eyewash locations, safe operating procedures.

Common Misuse

Hazard alerting of any kind.

2. What Each Part of the Z535 Series Actually Governs

"ANSI Z535" is five coordinated standards. Knowing which part applies keeps you from citing sign rules for a label problem — a distinction that matters when an auditor asks which document you designed to.

Part	Title	Scope In Practice
Z535.1	Safety Colors	Defines the precise safety red, orange, yellow, green, and blue (Munsell references) used across every other part.
Z535.2	Environmental & Facility Safety Signs	Wall and equipment-mounted signs in workplaces — layout, letter heights, and safe viewing distance math.
Z535.3	Safety Symbols	Criteria for the graphical panels: surround shapes, prohibition slashes, and comprehension testing.
Z535.4	Product Safety Signs & Labels	The label ON the product or machine — the format arc flash and equipment hazard labels follow.
Z535.5	Safety Tags & Barricade Tapes	Temporary hazards: lockout tags, out-of-service tags, barricade tape for transient conditions.

Where OSHA fits

OSHA 29 CFR 1910.145 remains the enforceable regulation for accident prevention signs and tags. Its 2013 revision recognizes the ANSI Z535-2011 series as compliant, so a Z535-formatted program satisfies both the modern standard and the legacy OSHA specifications it grew from. Design to Z535; cite 1910.145.

3. Producing Z535 Headers In-House

The color fidelity requirement is the practical hurdle: safety red and safety orange are defined colors, not "approximately red." Facilities solve it one of two ways:

Pre-printed header stock + black thermal transfer

The DANGER / WARNING / CAUTION panel arrives factory-printed in certified color on B-595 vinyl; your printer adds only the black message and symbol. Cheapest per label, zero color calibration risk, but you stock one roll per header type.

Multi-color sign printer, blank stock

An i5300 / BBP37-class printer lays down the header color and message in one job from blank B-595 or B-7569 rolls — one inventory item covers every signal word, plus ASME A13.1 pipe markers from the same machine.

Either route, the substrate does the surviving: for wash-down areas, chemical exposure, and outdoor mounting, check the material against our chemical resistance database before standardizing.

Labeling hazards on electrical gear specifically?

Arc flash labels are the highest-stakes application of the Z535 format — our companion guide covers the exact data NFPA 70E 130.5(H) requires inside the WARNING panel.

Read the Arc Flash Label Guide