Signs, labels, and other postings perform a valuable function at UMSL as a means of communicating where radioactive materials are stored and used. Many people who frequent the laboratory buildings are not trained as radiation workers, or may not be familiar with the operations in a particular laboratory. Proper signs, labels, and postings are an important indication of diligence and good practice on the part of the laboratory to ensure the safe keeping and handling of radioactive materials
Any space containing radioactive materials should be posted with the standard yellow-and-magenta sign bearing the tri-foil symbol and the words "Caution: Radioactive Materials". At UMSL, all rooms authorized for use or storage of radioactive materials must be so posted on the doorway placard.
Signs bearing the words "Caution: Radiation Area" are generically different than "Caution: Radioactive Materials", under state and federal regulations. "Caution: Radiation Area" signs are only to be used in cases of substantial sources of penetrating photon radiation (gamma and x-rays). Such areas are not common in modern biomedical research, but sometimes do occur. Certain laboratories at UMSL may have to be restricted or designated as a radiation area. This laboratory designation is based on the external dose. For instance, any laboratory maintaining activity amounts listed in Section 2.7.2 of the Handbook would be designated as a restricted or radiation area, as applicable.
You should specifically designate areas within the laboratory that will be used for radioactive materials. This area should be marked with tape bearing "Caution: Radioactive Materials" warning. The marked area must be treated as being potentially contaminated during periods of use, even when regular surveys are being performed.
During extended periods of no use, subsequent to a thorough contamination survey demonstrating that these surfaces are not contaminated, the labeling may be removed until use is resumed. Examples of areas to be labeled include:
