Signal Words and Major Message
Train Workers to Recognize and Understand Safety Signs

Safety signs are intended to indicate and, define industrial hazards that if not recognized may present a hazard and lead to an accidental injury to workers and the public, or to property damage.

According to 29 CFR 1910.145, “Specification for Accident Prevention Signs and Tags,” the word “sign” refers to a “surface prepared for the warning of, or safety instruction of, industrial workers or members of the public who may be exposed to hazards.”

These specifications are intended to cover all safety signs except those designed for streets, highways, railroads, and marine regulations. They do not apply to plant bulletin boards or to safety posters. Signs should be classified according to use, and there should be no variation in the type of design of signs posted to warn of specific dangers and radiation hazards.

All employees shall be instructed that danger signs indicate immediate danger and that special precautions are necessary. Caution signs are to be used only to warn against potential hazards or to caution against unsafe practices.

All employees shall be instructed that caution signs indicate a possible hazard against which proper precaution should be taken.

Safety Instruction Signs

Safety instruction signs shall be used where there is a need for general instructions and suggestions relative to safety measures.

Sign design features: All signs shall be furnished with rounded or blunt corners and shall be free from sharp edges, burrs, splinters or other sharp projections. The ends or heads of bolts or other fastening devices shall be located in such a way that they do not constitute a hazard.

Danger sign colors should be red, black and white, and used in major hazard situations where an immediate hazard presents a threat of death or serious injury to employees.

Caution signs: Standard color of the background shall be yellow; and the panel, black with yellow letters. Any letters used against the yellow background shall be black.

Safety instruction signs shall be white; and the panel, green with white letters. Any letters used against the white background shall be black.

Slow-moving vehicle emblem: This emblem consists of a fluorescent yellow-orange triangle with a dark red reflective border. The yellow-orange fluorescent triangle is a highly visible color for daylight exposure. The reflective border defines the shape of the fluorescent color in daylight and creates a hollow red triangle in the path of motor vehicle headlights at night. The emblem is intended as a unique identification for, and it shall be used only on, vehicles, which by design move slowly (25 mph or less) on public roads.

Sign Wordings

The wording of any sign should be easily read and concise. The sign should contain sufficient information to be easily understood, and the wording should make a positive, rather than negative suggestion and should be accurate in fact.

Biological hazard signs: The biological hazard warning shall be used to signify the actual or potential presence of a biohazard and to identify equipment, containers, rooms, materials, experimental animals, or combinations thereof, which contain or are contaminated with viable hazardous agents.

On a tag, the Major message is that portion of a tag’s inscription that is more specific than the signal word and that indicates the specific hazardous condition or the instruction to be communicated to the employee. Examples include: “High Voltage,” “Close Clearance,” “Do Not Start,” or “Do Not Use” or a corresponding pictograph used with a written text or alone.

A pictograph is a pictorial representation used to identify a hazardous condition or to convey a safety instruction.

The Signal word is that portion of a tag’s inscription that contains the word or words that are intended to capture the employee’s immediate attention.

Tag means a device usually made of card, paper, pasteboard, plastic or other material used to identify a hazardous condition. Tags shall be used as a means to prevent accidental injury or illness to employees who are exposed to hazardous or potentially hazardous conditions, equipment or operations, which are out of the ordinary, unexpected or not readily apparent.

Tags shall be used until such time as the identified hazard is eliminated or the hazardous operation is completed. Tags need not be used where signs, guarding or other positive means of protection are being used.

General Tag Criteria

All required tags shall meet the following criteria:

• Tags shall contain a signal word and a major message;
• The signal word shall be either “Danger,” “Caution,” or “Biological Hazard,” “BIOHAZARD,” or the biological hazard symbol;
• The major message shall indicate the specific hazardous condition or the instruction to be communicated to the employee; and
• The signal word shall be readable at a minimum distance of 5 feet (1.52 m) or such greater distance as warranted by the hazard.

The tag’s major message shall be presented in either pictographs, written text or both. The signal word and the major message shall be understandable to all employees who may be exposed to the identified hazard.

All employees shall be informed as to the meaning of the various tags used throughout the workplace and what special precautions are necessary.

Tags shall be affixed as close as safely possible to their respective hazards by a positive means such as string, wire, or adhesive that prevents their loss or unintentional removal.

Danger Tags

Danger tags shall be used in major hazard situations where an immediate hazard presents a threat of death or serious injury to employees. Danger tags shall be used only in these situations.

Caution tags shall be used in minor hazard situations where a non-immediate or potential hazard or unsafe practice presents a lesser threat of employee injury. Caution tags shall be used only in these situations.

Warning tags may be used to represent a hazard level between “Caution” and “Danger,” instead of the required “Caution” tag, provided that they have a signal word of “Warning,” an appropriate major message, and otherwise meet the general tag criteria.

Biological hazard tags shall be used to identify the actual or potential presence of a biological hazard and to identify equipment, containers, rooms, experimental animals, or combinations thereof, that contain or are contaminated with hazardous biological agents. FSM