Here is a selection of eight trefoils and radiation warning signs in common international use.
They are free to use. To download, hover your mouse over the the image or link to select and download. Note: there are also some variations in colour permitted for some labels.
Black and white (PDF,11 kB)
Labelling of radioactive materials.
Black and yellow 40mm (PDF,17 kB)
Labelling of containers generally.
Black and yellow 100mm (PDF, 31 kB)
Caution Radioactive Material (PDF, 211 kB)
Indicates a place where radioactive material is used or stored.
Use these warning signs to indicate a designated controlled area.
|Radioactive material, entry prohibited (PDF, 114 kB)|
|Irradiating apparatus, entry prohibited (PDF, 115 kB)|
|Radioactive material and irradiating apparatus (PDF, 120 kB)|
|X-rays, entry prohibited (PDF, 102 kB)|
General radiation warning sign
Use this warning sign to indicate the location of a particular hazard within a controlled area.
|Caution Radiation hazard (PDF, 91 kB)|