A restricted area is any area where access is controlled by the licensee for purposes of protection from radiation and radioactive materials (e.g., secured waste storage vaults).

An unrestricted area is any area to which access is not controlled by the licensee for the purpose of protection of individuals from exposure to radiation and radioactive materials.

A controlled area is any area to which access can be limited for any reason. Radionuclide use laboratories on campus are defined as controlled areas.

All persons using radioactive materials are responsible for the security of their laboratories and the radioactive materials within those labs. Laboratories in which radioactive materials are used must be locked when unattended. If a worker steps out for even a minute to go to the restroom or even the lab next door the door must be locked if no one remains in the laboratory.

Radioactive materials stored outside controlled areas must also be secured from unauthorized removal. The regulations permit the storage of radionuclides in locked and labeled refrigerators, freezers, or cabinets in unrestricted, uncontrolled areas such as hallways or open, general laboratories. The label must read “Caution Radioactive Material” and access to the key must be kept controlled.

Licensed materials in unrestricted and uncontrolled areas, not locked in storage, must be under the constant surveillance and immediate control of a trained Radiation or Laboratory Worker.

Any person entering a radionuclide laboratory who is unknown to you or your staff should be challenged as to the reason for their coming into your facility. Radiation exposure in both controlled and unrestricted areas must be kept below 0.05 mr/hr. Exposure levels must be verified by periodic radiation exposure monitoring.