OSHA defines a tag as a device made of card, paper, pasteboard, plastic or other material used to identify a hazardous condition.

OSHA’s standard 1910.145(a)(1) specifies that tags should be used 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.

Tags need to 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.
• The signal word shall be readable at a minimum distance of five feet 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. 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. 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 of paragraph (f)(4) of this section.

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.

Other tags. Other tags may be used in addition to those required by this paragraph (f), or in other situations where this paragraph (f) does not require tags, provided that they do not detract from the impact or visibility of the signal word and major message of any required tag.

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