What is the difference between DANGER and WARNING?

The difference is likelihood. DANGER is for a hazard that will cause death or serious injury if it is not avoided; WARNING is for one that could. Both involve the same severe outcome.

When should I use CAUTION instead of WARNING?

Use CAUTION when the worst likely injury is minor or moderate, such as a cut, a minor burn or a bruise. If the hazard could cause death, amputation or another serious injury, WARNING or DANGER is the better fit.

Can NOTICE be used for a safety hazard?

No. In the ANSI Z535 system NOTICE is for practices not related to personal injury, such as protecting equipment or property, and it is shown without the safety alert symbol. If someone could be hurt, use CAUTION, WARNING or DANGER.

Does OSHA recognize WARNING signs?

Indirectly. OSHA's general industry sign rule, 29 CFR 1910.145(c), names only danger, caution and safety instruction signs, though its tag rule allows WARNING tags. WARNING signs are part of ANSI Z535.2, which OSHA references in its construction sign rule and in the 2013 signage update; see our OSHA guide for detail.

What signal word goes on a label that covers several hazards?

Use the signal word for the most serious hazard on the label. If the hazards differ widely in severity, separate labels are often clearer.

Are GHS chemical label signal words the same as ANSI signal words?

No. GHS-based chemical labels, including US HazCom and Canadian WHMIS labels, use only two signal words, "Danger" and "Warning", assigned by the chemical's hazard classification. They follow different rules from ANSI Z535 safety signs; see our WHMIS guide .

Can I order a label with any of these signal words?

Yes. The label builder offers DANGER, WARNING, CAUTION, NOTICE and SAFETY INSTRUCTIONS headers. You choose the signal word; we print what you approve on the proof.

DANGER vs WARNING vs CAUTION vs NOTICE

The signal word is the first thing anyone reads on a safety sign or label, and in the ANSI Z535 system it carries a specific meaning. Picking the right one is not about how strongly you feel about a hazard; it is about how severe the likely injury is and how likely it is to happen if the hazard is not avoided. This guide sets out the definitions as ANSI Z535 frames them (in our own words), the colors, and common mistakes.

The five signal word levels

DANGER

DANGER marks a hazardous situation that, if not avoided, will result in death or serious injury. It is meant for the most extreme cases, where the outcome is close to certain if someone interacts with the hazard: exposed high-voltage conductors, an unguarded point of operation on a running press, entry into a space with a lethal atmosphere. The signal word is white on a red background, with the safety alert symbol.

WARNING

WARNING marks a hazardous situation that, if not avoided, could result in death or serious injury. The possible outcome is just as severe as DANGER, but it is not as likely: moving parts behind a guard that might be removed, stored pressure released during service, a fall from a platform. The signal word is black on an orange background, with the safety alert symbol.

CAUTION

CAUTION marks a hazardous situation that, if not avoided, could result in minor or moderate injury: a hot surface that can cause a minor burn, a sharp edge that can cut, a low beam that can bump a head. The signal word is black on a yellow background, with the safety alert symbol.

NOTICE

NOTICE is for information that matters but is not about personal injury: practices that prevent damage to equipment or property, or site policies. "Do not pressure wash the control panel" and "Authorized personnel only beyond this point" are typical. The word is white italic on a blue background, and there is no safety alert symbol, because the alert symbol means a personal injury hazard.

SAFETY INSTRUCTIONS

Safety instruction labels and signs give safe practices or procedures rather than warn of a specific hazard: "Wear safety glasses in this area", "Lockout procedure", "Emergency shutdown steps". The heading (SAFETY INSTRUCTIONS, SAFETY PROCEDURES or similar) is white on a green background.

Comparison table

Signal word	Meaning (paraphrased from ANSI Z535)	Panel colors	Safety alert symbol	Example
DANGER	Will result in death or serious injury if not avoided	White letters on red	Yes	Exposed live parts at hazardous voltage
WARNING	Could result in death or serious injury if not avoided	Black letters on orange	Yes	Rotating shaft behind a removable guard
CAUTION	Could result in minor or moderate injury if not avoided	Black letters on yellow	Yes	Hot surface that can cause a minor burn
NOTICE	Practices not related to personal injury	White italic letters on blue	No	Do not stack pallets against this panel
SAFETY INSTRUCTIONS	Safe practices, procedures or the location of safety equipment	White letters on green	No	Eye protection required in this area

How to choose: severity and likelihood

Two questions decide the signal word:

How bad is the worst credible injury? Death or serious injury (amputation, permanent disability, severe burns) points to DANGER or WARNING. Minor or moderate injury points to CAUTION. No injury at all points to NOTICE.
How likely is it, if the hazard is not avoided? "Will happen" points to DANGER. "Could happen" points to WARNING (or CAUTION, for lesser injuries).

The answers should come from your hazard analysis or risk assessment, not from the label shop. The person who knows the equipment and the task is in the best position to judge severity and likelihood.

Where OSHA fits

OSHA's general industry rule, 29 CFR 1910.145, uses an older three-way scheme for signs: danger signs for immediate danger, caution signs for potential hazards or unsafe practices, and safety instruction signs for general safety information. It sets colors for each. For tags, 1910.145(f) allows DANGER and CAUTION tags and permits WARNING tags for a hazard level between the two. OSHA's 2013 signage update added references to the ANSI Z535 standards, which include WARNING and NOTICE signs, to its sign rules. Read the OSHA sign requirements guide for the exact scope of that update.

Common mistakes

Using DANGER everywhere. If every sign says DANGER, people stop treating DANGER as special. Save it for hazards where serious harm is close to certain.
Using CAUTION for property damage. Older labels sometimes used CAUTION without the alert symbol for equipment damage. Current ANSI practice uses NOTICE for messages that do not involve personal injury.
Adding the safety alert symbol to NOTICE or safety instruction labels. The triangle signals a personal injury hazard; putting it on a NOTICE label sends a mixed message.
Mixing systems on one site. Old red-black-white "DANGER" signs, new ANSI-format signs and ISO symbol signs can coexist, but a consistent scheme across a facility is easier to train on. Plan replacements so similar hazards end up with similar signs.
A strong signal word with a vague message. "WARNING: Be careful" tells no one anything. The message should name the hazard, the consequence and how to avoid it.
Several hazards, the wrong signal word. A combined label should carry the signal word of its most serious hazard, or be split into separate labels.
Letting colors fade. A faded orange WARNING panel can read as CAUTION yellow. Choose a stock and overlaminate suited to the environment and replace labels that have faded. Ourmaterials guide covers this.
Confusing ANSI signal words with chemical label signal words. GHS chemical labels use "Danger" and "Warning" by hazard class and category, under their own rules.

Shop by signal word

Stock designs are grouped by signal word: DANGER signs,WARNING signs, CAUTION signs andNOTICE signs. For product labels with your own wording, seecustom DANGER labels, custom WARNING labels, custom CAUTION labels,custom NOTICE labels andcustom safety instruction labels, or start in thelabel builder.