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4732.0385 CAUTION SIGNS.

Subpart 1.

Standard radiation symbol and labeling.

Each radiation sign or label must bear the standard symbol specified in this subpart and the printed warning, in capital block letters, specified in subpart 4. The standard symbol for designating any radiation hazard is a circle with three propeller-like blades arranged around it as illustrated:

25 picas - Insert radiation hazard symbol here


cross-hatched area shall be magenta, purple, or black; and


the background shall be yellow.

Subp. 2.

Additional information on signs and labels.

In addition to the contents of signs and labels prescribed in this part, the registrant must provide, on or near the required signs and labels additional information, as appropriate, to make individuals aware of potential radiation exposures and to minimize the exposures.

Subp. 3.

Prohibitions on use of symbol.

The use of the specified radiation symbol for any purpose other than designating or referring to an area of applicable radiation levels is prohibited.

Subp. 4.

Posting and labeling requirements.

Conspicuous radiation warning labels must be posted in areas in which a radiation hazard may exist.


The warning "CAUTION RADIATION AREA" or "DANGER RADIATION AREA" must appear on signs in an area in which a radiation hazard may exist.


The warning "CAUTION HIGH RADIATION AREA" or "DANGER HIGH RADIATION AREA" must appear on signs in an area in which a high radiation hazard may exist.


The warning "CAUTION VERY HIGH RADIATION AREA" or "DANGER VERY HIGH RADIATION AREA" must appear on signs in an area in which a very high radiation hazard may exist.


Analytical ionizing radiation-producing equipment complying with part 4732.1000 must be labeled with a readily discernible sign or signs bearing the radiation symbol and the words:


"CAUTION - HIGH INTENSITY X-RAY BEAM," or words having a similar intent, on the radiation-producing equipment housing; or


"CAUTION RADIATION - THIS EQUIPMENT PRODUCES IONIZING RADIATION WHEN ENERGIZED," or words having a similar intent, by any switch that energizes an x-ray tube.

Subp. 5.

Exceptions to posting requirements.


A registrant is not required to post caution signs because of the presence of radiation machines used solely for diagnosis in the healing arts.


Rooms in hospitals or clinics that are used for teletherapy are exempt from the requirement to post caution signs under this part if:


access to the room is controlled according to part 4732.0620; and


personnel in attendance take necessary precautions to prevent the inadvertent exposure of workers, other patients, and members of the public to radiation in excess of the limits established in this chapter.

Statutory Authority:

MS s 144.12


32 SR 777

Published Electronically:

April 25, 2023

Official Publication of the State of Minnesota
Revisor of Statutes