The control of contamination is important in the prevention of the uptake and spread of radioactive material. The following precautions may be implemented during procedures to help control contamination:
Surface Contamination
- The use of a spill tray should be considered.
- Absorbent paper should be placed on lab benches and spill trays to limit the spread of contamination and aid in the clean-up of contaminated areas.
- Containers or instruments used in radioactive processes should be labeled with a radioactive symbol (e.g., radioactive tape).
- Radioactive material use should be confined as much as possible within designated areas of the lab (e.g., used in a hood).
- Laboratory surveys should be completed.
- Precautions should be made when chemicals may become volatilized (e.g., 35S amino acids in incubators, 3H water storage in freezers).
Personal Contamination (Internal and External)
- Disposable gloves must be utilized when handling any radioactive material. These gloves should be monitored periodically and changed frequently.
- Lab coats should be worn to protect clothing. They should be checked for contamination periodically and may be laundered without special precautions providing contamination is not present.
- Eating, drinking, smoking, storing consumables, and/or applying cosmetics is prohibited in labs.
- Mouth pipetting of radioactive material is prohibited. Mouth pipetting of non-radioactive material in radionuclide laboratories is strongly discouraged.
- Bioassays may be required for individuals utilizing large quantities of radioactive material and/or certain volatile radionuclides (e.g., 125I sodium iodide). The RSO may also require bioassays in the event of an accident involving personal contamination.
- Hands and clothing should be surveyed periodically during and after procedures involving the use of radioactive material. Such surveys may be in the form of a direct radiation survey with a portable survey instrument and/or a wipe survey.
Airborne Contamination
- The RSO requires the use of fume hoods for procedures involving the generation of volatile radioactive material (e.g., when iodinating).
- Special filtration may be required depending on the chemical form used. Such requirements are generally specified in the PH's permit.
Control of External Exposure for High Energy Beta and Gamma Emitters (e.g., 32P, 22 Na, etc.)
- Exposure can be minimized by storing the radionuclide in the original shipping container well away from constantly occupied areas. Additional shielding is required if the exposure rate is greater than 2 mR/hr (or equivalent count rate) at 30 cm from the source.
- For new procedures, dry runs without the use of radioactive material are recommended to improve technique and minimize time of exposure. For extremely hazardous operations, dry runs under the supervision of the RSO may be required.
- Tongs or forceps should be used for the direct handling of unshielded vials containing more than a few microcuries of activity if long handling times are required (e.g., longer than a few seconds). Vessels containing millicurie quantities should rarely be handled directly with the fingers.
- A direct radiation survey may be required during and after procedures involving certain quantities of radioactivity.
