Warning Signs

Q: "What does a warning sign mean?"

"A warning sign indicates a hazardous situation that, if not avoided, could result in death or serious injury. It is the middle severity level in the ANSI Z535 signal word hierarchy, above caution and below danger."

Q: "What color are warning signs?"

"Warning signs use a safety orange header with black lettering, as defined by ANSI Z535.1 and Z535.2. The orange header distinguishes them from red danger signs and yellow caution signs."

Q: "Does OSHA recognize warning signs?"

"Yes. OSHA's 2013 update to 29 CFR 1910.145 incorporated the ANSI Z535 standards, which include the WARNING signal word, as an accepted approach to safety sign design."

ANSI Z535 Warning Signage for Hazards That Could Cause Serious Injury

Workplace Safety Signs

Warning Signs for Serious Hazards, Clear Communication, and OSHA Compliance

Warning signs identify hazardous situations that, if not avoided, could result in death or serious injury. They sit between danger and caution in the ANSI Z535 signal word hierarchy, covering serious hazards that are not immediate enough to demand a DANGER header. Clarion Safety's warning signs use the safety orange format defined by ANSI Z535, recognized by OSHA in its 2013 update to 29 CFR 1910.145, which incorporated the ANSI Z535 standards as an accepted design approach. Our custom sign services can adapt any warning message to your facility, including translated and multi-lingual formats.

When a Warning Sign Is the Right Choice

Choose a warning sign when the hazard could kill or seriously injure, but the risk does not rise to the immediacy required for a danger sign.

Common applications include:

Machinery hazards such as crush points, entanglement, and automatic startup
Elevated work areas and fall hazards
Hazardous chemicals and process equipment
Vehicle traffic areas such as forklift lanes and loading docks

Warning vs. Danger vs. Caution: The Severity Hierarchy

The ANSI Z535 standards assign each signal word a precise meaning. A danger sign is used when the hazard will result in death or serious injury if not avoided. WARNING covers hazards that could result in death or serious injury. A caution sign covers hazards that could result in minor or moderate injury, and a notice sign carries important information not related to personal injury. Our overview of ANSI Z535.2 best practices covers how to apply the hierarchy across a full facility sign system.

Building out your facility's sign system? Clarion's experts can help you apply the right severity level across every hazard. Contact our team for a consult.

Frequently Asked Questions About Warning Signs

What does a warning sign mean?

A warning sign indicates a hazardous situation that, if not avoided, could result in death or serious injury. It is the middle severity level in the ANSI Z535 signal word hierarchy, above caution and below danger.

What color are warning signs?

Warning signs use a safety orange header with black lettering, as defined by ANSI Z535.1 and Z535.2. The orange header distinguishes them from red danger signs and yellow caution signs.

Does OSHA recognize warning signs?

Yes. OSHA's 2013 update to 29 CFR 1910.145 incorporated the ANSI Z535 standards, which include the WARNING signal word, as an accepted approach to safety sign design.