The use of warning or caution signs are required to alert unauthorized or unsuspecting personnel of a hazard and to remind authorized personnel as well. There are some exceptions to posting if approved in advance by Health Physics and if the material is supervised by a trained individual approved to handle radioactive material by Health Physics.

Radioactive Materials, Radiation Areas, High Radiation Areas, Very High Radiation Areas, Airborne Radioactivity Areas, shipping containers and vehicles shall be marked or posted as required by various regulations. Health Physics will assist in providing the necessary information, signs, and/or labels.

All signs, labels, and signals will be posted in a conspicuous place.

The standard radiation symbol appears with the required trefoil symbol as shown below. The symbol is magenta, purple, or black on a yellow background.