Some of the common questions that we receive are listed below with the answers. This section is intended to be a
resource for quick information. If you need more information or information not listed below, please contact the Tufts University EHS Radiation Safety at 617-636-3450.
Q. Who is required to attend a monthly Radiation Safety Training session?
A. Any persons who plan to use radioactive materials on any Tufts Campuses require Radiation Safety Training.
Persons who frequent areas where radioactive materials are used or stored, also should attend Radiation Safety Training. Persons who will use machine sources of ionizing radiation [x-ray equipment] must attend Radiation Safety Training. See Tufts Radiation Safety Training schedule.
Q. Who needs a radiation badge at Tufts?
A. Persons who handle high energy beta emitting radioactive materials [ex. P-32] , gamma emitters [ex. Tc-99m] or use x-ray equipment should obtain a radiation body badge. Persons who handle over 10 mCi of high energy beta or gamma emitters may also need a ring badge. Persons using only H-3, C-14 and S-35 will not be provided badges as radiation from these low energy beta emitters can not be recorded on the badge monitor.
Q. How do I apply for a radiation badge?
A. Radiation badge applications are available on our website. See the section called “Forms”. Complete the application and send it to the Health Physics Group in Boston. You must provide information about the type(s) of radiation that you will be using and the amounts so that the appropriate types of badges and/or rings may be assigned to you. Your badge(s) will be issued and sent to you as soon as possible. If you need your badges immediately, you may stop by the Health Physics Group office at 49 Holmes St. in Boston.
If you have questions, in Boston and Grafton, please contact the Radiation Safety Officer at 617 636-3450. In Boston the Health Physics Group (HPG) at x66168 also has forms. In Medford, please contact Tufts EHS at 617-636-3450.
What is ALARA?
ALARA is a philosophy of excellence used in one’s day-to-day work with radioactive materials. It is when one strives to keep one’s radiation exposure As Low As Reasonably Achievable. Some, often easy, changes in procedures can greatly reduce one’s radiation exposure. The ALARA philosophy encourages one to actively seek out these methods of exposure reduction. Examples include use of tongs to handle radioactive material vials containing large activities or high energy emitters. One should strive to have the good practices become “second nature” and work in this
manner each and every day when handling radioactive materials or radiation sources. See online “Extremity Dose Reduction ” information.
Q. What are the commonly used radioactive materials at Tufts?
A. Low energy beta emitters are the most commonly used radioactive material at Tufts. These include H-3 [tritium] S-35 and C-14 labeled compounds. High energy emitters such as P-32 are also commonly found in research laboratories. Gamma emitters such as Tc-99m can be used in limited areas of the University.
Q. Can I work with radiation producing equipment or radioactive materials if I am pregnant?
A. Generally, yes. The vast majority of work performed at Tufts with radioactive materials can continue without modification during pregnancy. Once a person officially informs her employer in writing of her pregnancy, new dose limits apply. A person can obtain a second film badge which can be worn at the waist to monitor the exposure to the unborn child. Regulations require that the dose for the 9 months of pregnancy must not exceed 500 mRem. Tufts strives to keep declared pregnant worker’s doses to < 50 mRem. The Radiation Safety Officer can review your prior exposure history and your current projects that involve the use of radioactive materials or radiation producing equipment. This will provide an estimate of the likely exposure that may be received during the duration of pregnancy. This review may also result in suggestions to further reduce your exposure to radiation. Because the fetus is sensitive to radioiodine, it may be suggested that you not perform iodinations during your pregnancy. Because of the increased sensitivity of the fetus, RS personnel may suggest you limit your use of some very large sealed sources of radioactive material. In 2006 and 2007, most workers at Tufts received a whole body doses less than 50 mRem. See the “Pregnancy and Radiation ” page for more information.
Q. Is there a limit to the amount of radioactive material that can be in my laboratory at one time?
A. Each Principal Investigator is authorized by their respective Radiation Safety Committee (RSC) for certain amounts of specific radioactive materials. To possess larger amounts, the radioactive material use authorization must first be reviewed and amended. All amendment requests must be submitted using the PI application form.
Q. Can I take my radioactive material to another facility outside Tufts?
A. After completing the necessary regulatory requirements, radioactive material may be shipped from Tufts. There are very specific regulations about the transport of RAM on public streets. Radioactive material may NOT be taken on Tufts shuttles, buses, trains or in personal vehicles. Arrangements for the shipment of radioactive material in certified shipping containers and by approved carriers may be made by contacting the Radiation Safety Officer at 617-636-3615. Because special DOT training is required for all shippers of radioactive material, trained personnel will assist you in completing the necessary shipping papers for transport of radioactive material outside of Tufts University or between campuses. The individual researcher is responsible for all shipping charges.
Q. How do I purchase x-ray equipment or lasers at Tufts?
Prior to purchase of any x-ray equipment [fluoro, C-arms, general diagnostic, x-ray diffraction, etc.] Boston Health Physics + TEHS Radiation Safety should be notified as soon as possible so that shielding and other safety requirements can be evaluated. X-ray equipment must also be registered with the MA Radiation Control Program [MA RCP]. Any fees are the responsibility of the unit owner/researcher. Contact the Radiation Safety Officer at 617-636-3450.
Class 3b and 4 lasers also must be registered with the MA RCP. In addition, a safety evaluation must be performed prior to use of the laser. Contact Tufts EHS office when planning the purchase of Class 3b and 4 lasers at 617-636-3450.
[Note: Under a new classification system for lasers, Class 3b lasers may also be referred to as Class 3B].
Q. Can tritium containing Exit signs be used at Tufts?
A. Tritium exit signs are sold under a general license from the US Nuclear Regulatory Commission. Intact signs can be handled without special precautions except to avoid damaging the sign. However, they contain very large amounts of radioactive material in the form of tritium gas. These signs should not be purchased or used at Tufts University.
Costs can be very high when it is time to dispose of these signs. There are only a limited number of disposal options for them. Some universities have paid thousands of dollars to dispose of just a few tritium exit signs. There have also been incidents where cleanup from damaged tritium exit signs has cost tens of thousands of dollars. Special training is required to ship tritium exit signs.
If a tritium exit sign is lost, regulatory agencies need to be notified. If a tritium exit sign is damaged, it must be disposed of properly. Alternative signs which are hard wired or battery operated are preferred. Prior approval from the Tufts Radiation Safety Committee is required to purchase, replace or use tritium exit signs at Tufts University.
DO NOT REMOVE OR DISPOSE OF TRITIUM EXIT SIGNS-CONTACT THE RADIATION SAFETY OFFICER at 617 636-3450.
If you see a tritium exit sign at Tufts, please notify the Radiation Safety Officer at 617-636-3450. If you find a damaged tritium exit sign, please immediately contact Tufts RSO as above. After hours, contact campus police who will summon someone from radiation safety for you.
If you break a tritium exit sign, leave the area. Ventilate the area if feasible. Contact Radiation Safety. Further information on tritium exit signs is available as an Adobe Acrobat PDF File: Tritium Exit Signs.
A. A tritium exit sign has a radioactive materials label on it. The label is often on the bottom or an edge. The radiation trefoil symbol is usually visible. Other information about when the sign was manufactured and how much tritium it contains [for example, 7 Curies] is also on the label. These signs tend to have a thin profile, usually less than 1 ½ inches thick.
If you are not sure if a sign contains tritium, please contact either the RSO. Further information on tritium exit signs is available as an Adobe Acrobat PDF File: Tritium Exit Signs.
Q. Does lab equipment require decontamination prior to disposal, repair or servicing?
A. There are strict regulations about the disposal of radioactive material. Equipment for disposal must be surveyed prior to release for disposal by members of the Health Physics Group in Boston, or by TEHS personnel or consultants at the Grafton and Medford Campuses. For equipment which has been used with radioactive material [centrifuges, hoods, pipette man, etc.] and which needs repairs, a survey must be completed prior to allowing service providers to service the equipment. In Boston, contact the Radiation Safety Officer at 617 636-3450 or the Health Physics Group at 617-636-6168. For Medford or Grafton Campuses call Tufts RSO at 617-636-3450.
Q. How do I get permission to use special large radioactive sources at Tufts?
A. Contact the Health Physics Group at 617-636-6168 for forms. Your application will be reviewed by the RSO and Tufts University Human Resources.
Q. What is an iodination?
A. An iodination is a chemical procedure used to attach a radioactive tracer to a compound of interest. This compound is often a protein such as on a cell surface or a hormone or antigen. The isotope I-125 is most commonly used for producing radiolabeled compounds, although other isotopes of radioiodine may also be used. Specific iodination methods include Chloramine-T, Bolton Hunter, Iodogen and Iodo-bead methods. All iodinations should be performed in a certified fume hood by trained, authorized personnel. Thyroid counts should be obtained by all individuals prior to working with radioactive iodine. Thyroid counts are also required for those individuals performing iodinations using greater than 1 mCi. The thyroid count must be obtained within 2 days of performing an iodination. Quarterly thyroid counts may be required for individuals who work with iodine but do not actually perform iodinations.
Stock vials containing mCi amounts of 125 I should be shielded as these vials can generate substantial radiation on the outside surface of the vial and the surrounding air volume. A thickness of 2 millimeters of lead is sufficient to shield most standard stock vials. When handling potentially volatile 125 I, perform the reaction in the original shipping vial, working through the septum with a syringe and hypodermic needle whenever feasible. All stock vials containing volatile 125 I compounds should be purged prior to use. Purging the airspace of the stock vial through a trap containing activated charcoal will prevent an initial release of built-up volatilized activity. This will assist in significantly reducing environmental releases, contamination of facilities and possible internal personnel exposures. Purging is accomplished by first inserting the hypodermics of both a charcoal trap and an air filled syringe through the septum of the closed stock vial. Be certain that the tips of the hypodermics reside in the airspace of the stock vial and are not touching the liquid. Slowly and gently inject the air from the syringe into the stock vial, causing an exchange of air and forcing the volatilized activity from the stock vial into the charcoal trap. Remove the syringe and then the charcoal trap. Discard the used syringe and the charcoal trap into the 125 I waste. Do not recap hypodermic needles.