Section 6: Radiation Warning Signs and Labels

A. Posting Requirements

  • A radiation warning sign shall be posted at each laboratory entrance door where ionizing radiation may be present. Radiation signs, as well as other hazard signs, should be posted as required by the individual laboratory. Individual signs should be used as necessary within the laboratory. Sites where radioactive materials are stored or manipulated must be indicated by radiation signs or symbols.

B. Placarding Requirements

  • The posted information shall include the standard symbol, information about the type and quantity of radiation in use, special precautions to be observed when entering the area, and the name of a person to be contacted in case of emergency.

C. Obtaining Signs

  • Sign requirements may be obtained from the Radiation Safety Officer.

D. Types of Signs

  • In general, the following signs are used:

      • This sign should be posted wherever unsealed sources of radioactive materials are used or stored.
      • It may also be used for sealed sources where the radiation exposure is less than 5 millirem per hour at 6 inches.

      • This sign should be posted wherever radiation exposure is such that one might receive more than 5 millirem.
      • If the source is in a container, the level may be measured at 6 inches from the container.

      • This sign should be posted when radiation exposure is such that one might receive more than 100 millirem in any 1 hour.
      • High radiation areas which will exist for 30 days or more require visible or audible warning signals.
      • Any high radiation area which does not have an interlock to deny entry to the area should have an operator on duty at all times.

    4. CAUTION HIGH RADIATION (when unit is operating)
      • This sign is for devices which emit ionizing radiation only when turned on (x-ray devices, accelerators, etc.).

      • This sign should be posted while decontamination procedures are being carried out.
      • Posting of the signs should never be allowed to replace immediate cleanup of the contamination.
      • The person responsible for contamination is responsible for decontamination.
      • In case of serious contamination, the Radiation Safety Officer should be notified.

      • This sign shall be posted or adjacent to each x-ray tube housing so as to be clearly visible to any individual who may be working in close proximity to the beam path.
      • This sign applies to non-medical, open beam x-ray equipment.

E. Smaller Signs, Labels, and Tape

  • Smaller signs of the stick-on type, tags, or radiation tape may be purchased by the AU faculty member to designate areas or containers used for radioactive materials. However, proper signs of the above types should be used to designate all areas where ionizing radiation is present.

    1. All containers of radioactive materials should be labeled with...
      • isotope,
      • quantity,
      • date,
      • chemical form (where possible).

    2. Containers being used in the laboratory with less than 1 microcurie and with the user constantly present need not be labeled.
    3. Any Sealed source which is not fastened to or contained in a radiographic exposure device shall have permanently attached to it a durable tag at least 1 inch square bearing the radiation symbol and the following instructions: "Danger-Radioactive Material-Do not Handle-Notify Civil Authorities if Found"