To use radioactive materials at Washington University, a principal investigator must become an Authorized User.  Information regarding the process of becoming an Authorized User and maintaining your authorization can be found below.  If you cannot find the information you are looking for, please contact the Radiation Safety Office at 314-362-3476 or

Becoming an Authorized User of Radioactive Materials

To become an authorized user, you must be a faculty member of the institution(s) and have had greater than 40 hours of training and hands-on experience with radioactive materials.  You will need to submit an application identifying the proposed isotopes, activities, uses, locations of use and storage, radiation workers, etc., with an accompanying training and experience statement form.  Upon receiving and reviewing your application, a member of Radiation Safety will conduct an Authorized User interview.  You will also need to pass our Radiation Safety Exam and possibly other specialty exams we have depending on the types of radioactive materials you will use. 

The EH&S Radiation Safety Committee (RSC) Applications Subcommittee evaluates requests for use of radioactive materials in non-human research.  Their recommendations are subject to final approval by the RSC.

Authorizations are good for 5 years.

How Long Will it Take to Get My Authorization Approved?
Depending on the completeness and accuracy of the application, approval for a new Authorized User (AU) should take between 2-4 weeks.  This time frame is dependent on how long it takes the new AU to take our exam(s), how quickly we can complete the AU interview, and how frequently the members of the Radiation Safety Committee Applications Subcommittee are able to meet during that time to approve applications.
Changing Details of Your Authorization (Amendments)

For changes to an authorization outside of the regular renewal cycle, we allow Authorized Users (AUs) to amend their authorization(s) by submitting an “amendment” form, available from the printable forms section of our website.  This form must be completed and approved prior to ordering a new isotope or increased levels of a currently approved isotope, using another location for the use or storage of radioactive materials, or beginning work with radioactive materials in live animals.

How Long Will it Take to Get My Amendment Approved?
Depending on the completeness and accuracy of the application, approval for an amendment should take between 2-10 days.   Area additions can be approved by the Radiation Safety Officer without going to Subcommittee for approval, so can usually be approved within 2-3 days.  Requests to add isotope(s) or change current approval amounts sometimes require more substantial evaluations by the Radiation Safety Staff and may also require subcommittee approval.  Please allow as many as 10 business days.
What Is “Inactive” Status?

The “inactive” status category is for an Authorized User (AU) who wants to have a radioactive materials authorization, but has no radioactive materials on hand and no firm plans to obtain materials within six months or more.  “Inactive” investigators are still Authorized Users and can indicate as such on grant applications, etc., but are excused from many of the radiation safety compliance requirements.

To qualify for “inactive” status, an Authorized User (AU) must: have no radioactive materials in use or storage of any kind, and no plans to obtain material for at least six months; commit to providing notice at least two weeks prior to needing radioactive materials; and commit to complying with the reactivation requirements prior to needing radioactive materials.  To request “inactive” status, or to find out more information about it, please contact your laboratory inspector.

Re-Activating From “Inactive” Status

To re-activate from “inactive” status, an Authorized User (AU) must complete the following items prior to ordering radioactive materials: re-interview with his/her Health Physics Reviewer; provide ALARA and Refresher training to existing radiation workers if they have not had it within the past 12 months; ensure that survey instruments and gamma or liquid scintillation counters are re-calibrated as needed; and cooperate with the Radiation Safety Staff in completing any required measurements, evaluations, postings, approvals and waste disposal procedure verifications.  Your authorization will then be re-activated exactly as it was at the time of inactivation.  Any necessary changes would have to made via an “amendment” form.

Using A Common Room Or Lab Already Approved For Radioactive Material Under Another Investigator

You will need to add the room to your own authorization. We need to track everyone who uses a room in conjunction with radioactive materials so that we can keep track of what isotopes and activities are used there. This is important in determining how the room needs to be posted and if any of the occupants may require dosimetry/bioassay.

Using Radioactive Materials in Live Animals

Initial requests for use of radioactive materials in live animals must be originated with either the renewal form at the time of authorization renewal or with an amendment form.  All animal protocols must be submitted to the Institutional Animal Care and Use Committee (IACUC) and are subject to their review and final approval.  IACUC will request Radiation Safety approval before granting final approval to any protocol that involves radioactive materials.

Adding Radiation Workers To Your Authorization

The Nuclear Regulatory Commission, the federal agency that licenses our use and possession of radioactive material (RAM), gives certain safety oversight responsibilities to an institutional committee, the Radiation Safety Committee (RSC). The RSC, in turn, delegates certain responsibilities to research faculty members by approving them to use RAM, i.e. to become an “Authorized User”. The faculty members who are granted authorization to use RAM are responsible for the safe use of the material both by themselves, and by the individuals working under their authorization. We have had some individuals tell us whose authorization they will be working under when they take one of our exams, and later we find out that the Authorized User does not know this individual is working under their authorization. For this reason, we feel it is important that the Authorized have the final authority to determine when that person is ready to be added to their permit by making a formal request to do so.

Authorized Users or their designated Radiation Safety Lab Contact may begin using the Radiation Worker Request Form, at any time, to request that a radiation worker be added to their permit(s). In the case of a brand new worker, the individual must bring this completed form with them when they take the Radiation Safety Exam (RSE) and/or PET exam. To add an existing radiation worker (one who has already taken the exam) to your permit, just send the completed Radiation Worker Request Form to Radiation Safety, or complete it in MyRad, and our staff will verify the exam status before adding the worker to your indicated permit(s).