The consistent control of radioactive material inventory is essential for regulatory compliance. Inventory must be available, presentable, and easily understood by an inspector. The most efficacious method is to have one inventory sheet for each vial your lab has ordered. A well managed inventory is also considered important measure of security. Standard inventory sheets can be downloaded from the Radiation Safety intranet forms page and are provided with each shipment. Please follow these guidelines when completing the inventory form:
- Receipt of Vials. An inventory form should accompany your isotope delivery. When opening the package be aware of the possibility of contamination and be prepared to use appropriate protection measures including lab coat, gloves, Geiger counter, and wipe tests. Notice if the packaging is damaged outside or inside. If the package integrity is good proceed in removing the vial. If the package integrity is questionable use a Geiger counter or wipe test to determine if there is contamination, and then proceed. Fill out appropriate information on the inventory form as soon as you bring the isotope into your lab and open the packaging. That information includes:
- P.I./Authorized User,
- Use/Storage Location,
- Date Vial Received,
- Amount Received,
- Isotope/Chemical Form,
- Package Survey Results,
- Lot # which is found on the vial label.
- Withdrawals by Individuals. Each time a researcher removed the vial from storage and aliquots a measure of isotope for use the inventory form must be updated. The most efficacious method is for the individual users to update the sheet. Therefore, the inventory sheets should be readily at hand for all the researchers. A common place is posted on the cabinet where the isotopes are stored. The required information includes:
- Date Used,
- Initials of user,
- Amount Used in either uCi or cc (cc is preferable),
- Balance (in cc or uCi) remaining.
- Disposal. As individuals use the stock from the vial the remaining balance (in cc) or the activity (in uCi) will eventually become zero. When this is the case the vial should be disposed to an appropriate radiation waste container. A laboratory should avoid having many empty or decayed vials of isotope in storage. Please follow these guidelines:
- Separate the vials from the outer containers (aka pig) and only dispose of the vial as radioactive waste. The outer pig is not considered radioactive waste unless it is contaminated.
- Separate any lead which may be used to line the pig. Lead should not be disposed in the regular trash; it should be stored in the laboratory and will be removed by radiation safety upon request.
- After completing the previous steps a through c the inventory sheet can be retired to the files. Records should be stored for at least 2 years.
- Only use appropriate color coded containers for radiation waste disposal,
When following this protocol every vial in storage in the laboratory will have an accompanying inventory sheet that describes in detail the history of its use. Anyone in the lab should be able to know how many cc's of which isotopes you have available for use at any given time, which vials are expired, and which ones have been disposed. Records should be kept for at least two years. Suggestions:
- Dispose of all old vials and pigs so you only have your currently used inventory in the lab.
- Place inventory sheets in convenient location for researchers.
- Keep inventory in lock location after hours and on weekends.
- Call Radiation Safety if there are any questions about procedures.
Contamination ControlContamination of laboratory surfaces and equipment is considered the most hazardous radiation condition a laboratory worker can face. The primary reason for this is the researchers are not likely to know the existence or whereabouts of the contamination. Then there exists a high probability that the contamination will be unknowingly picked-up, spread, and ingested by researchers. It is therefore most important for anyone using radioactive materials to check for contamination before and after working with radioactive materials. This can be accomplished by following these guidelines:
- Perform comprehensive wipe tests (liquid scintillation counting, LSC) every month regardless of the level of isotope use in the laboratory. This is not an option, monthly wipe tests are required by law. Wipe tests must conform to the following standards:
- The efficiency of the liquid scintillation counter youÕre using should be noted on the wipe count record which satisfies the DPM reporting requirements.
- There must be a record for each month of the year regardless of use. Wipe tests requirements are based on possession of radioactive materials NOT USE.
- Only the print-out from the liquid scintillation machine is considered adequate fulfillment of the requirement. Survey meterÕs can not be used to fulfill the wipe test requirement.
- Tritium can only be detected via LSC and often report Type I error due to organic contamination of the sample. All positive tritium LSC results must be recounted after at least 30 minutes. True positive results will show statistical consistency after multiple counts. False positive counts will not.
- Results greater then 3x background should be cleaned upon discovery. Equipment must be cleaned or removed from service if wipe test results exceed 5000 DPM.
- Wipe tests should include areas where isotopes are known to be used and areas where isotopes are not generally used.
- A survey meter should be used to check for contamination prior to, during, and after completing any work with radioactive materials.
- A standard GM probe is adequate for gamma isotopes except for I-125 where a special NaI probe is required.
- A standard GM probe is adequate for all betas except for Tritium which can not be detected using a survey meter. A wipe test is required to detect tritium contamination. Make sure to budget enough time to check for tritium contamination as part of the protocol.
- All survey meters are required by law to be calibrated each year. Calibration can be performed either by an outside vendor or by the radiation safety office.
- Labeling of all equipment used with radioactive materials is an essential part of minimizing the spread of contamination. Equipment which is identified as potentially contaminated should not be used for non-radioactive purposes.
- Remove any food or food like items from all lab areas and keep trash cans free of food related trash.
- Keep wipe test records orderly and easy to read by an inspector.
- Write LSC efficiencies on the wipe test printouts.
- Check that all equipment associated with radiation use is properly labeled.
- Waste logs should be attached to every waste bucket. Every time something is place in the waste container an entry should be made on the waste log. In other words there should never be an empty waste log if there is waste in the bucket.
- All waste containers must have a radiation symbol and indicate the specific isotope present. This is required for the color buckets AS WELL AS any other container being used for radioactive waste disposal or storage. Examples include bench top pipette containers, vacuum flacks, beakers, etc.
- Waste containers for P32 and all gamma isotopes should be checked to determine if shielding is necessary.
- Waste that is being stored in the laboratory for decay prior to disposal (decay in storage) must conform to the Department of Health regulations. Please see Radiation Safety Manuel for details regarding a compliant DIS program.
- Do not overfill waste containers. Liquid containers should not be filled past the shoulder of the container.
Radioactive waste will be generated in either liquid or solid form. All radioactive waste must be segregated according to color coded buckets, (see attached chart). If you are not sure which bucket to use for your waste, choose the isotope waste bucket with the closest half-life. To request replacement buckets and waste pick-up please log onto the eeLIMS core site. If you are not registered with eeLIMS please contact Alicia Clarens (66964). Researchers are welcome to pick-up empty buckets and labels from the Radiation Safety office anytime.
- Remove all decayed waste from the lab prior to inspection.
- Have radiation safety remove waste from the lab on a regular basis
- Periodically check waste labels. If there is something in the waste bucket, there must be something on the waste bucket label.
- Wipe test waste containers and decontaminate if greater than 5,000 DPM.
- Review decay in storage compliance.
- Do not leave waste on bench tops. Move waste to the colored buckets ASAP after working.
- Make sure all containers holding radioactive material are properly labeled with the radiation symbol and isotope present.
Personal ProtectionPersonal protection equipment (PPE) is designed to prevent a harmful substance from entering onto or into your body. PPE for laboratory radiation safety differs from that for chemical safety in only one category; dose measurement. Dose from handling radioactive materials can be measured by wearing a dosimeter. The three common types of dosimeters a laboratory worker might want to wear are a full body dosimeter, an extremity dosimeter, or a fetal monitor.
- Full body dosimeter is worn on the torso between the waste and neck outside the lab coat. It is designed to measure the dose a worker receives from a wide radiation field to the whole body. Only high energy beta such as P32 and gamma radiation can be measured. The dosimeter is not practical for low energy beta such as H3, C14, or S35.
- he extremity dosimeter is designed to measure the near field dose to your hands, feet, and arms. The most useful type is a ring dosimeter that is worn on the index finger of the dominant hand. In laboratory work the hands will generally receive most of the radiation dose. Ring dosimeters have the same limitations as the whole body dosimeters.
- Fetal monitors are worn by pregnant laboratory workers who have declared their pregnancy in writing. Please contact radiation safety for details regarding fetal monitoring.
- Fume hoods are part of the laboratory PPE. Malfunctioning or misuse of fume hoods can create a dangerous situation for laboratory workers. Always check for hood certification and proper flow rates between 75 and 130 ftm. Hoods that flow too much are as dangerous as ones that donÕt flow enough. Check that the hood isnÕt overcrowded with equipment which will prevent proper laminar flow.
- Dosimeters must be requested from radiation safety via the Dosimeter Request Form
- P32 workers must have a ring dosimeter
- Anyone using the irradiator must have a full body and ring dosimeter.
All isotopes must be secured against unauthorized removal. Labs must be locked unless there are workers present. Any isotope stored in hallways must be locked up at all times.
Only laboratory workers possessing a training certificate are authorized to handle isotopes. Certificated are issued after completing a 6 hour radiation safety course. Please refer the course schedule