An officially prescribed symbol (a magenta or black trefoil) on a yellow background that must be displayed where certain quantities of radioactive materials are present or where certain doses of radiation could be received.
RADIATION WARNING SYMBOL
Meaning of RADIATION WARNING SYMBOL in English
NRC Nuclear Energy English Glossary. Английский глоссарий ядерной энергии NRC (Национальный научно исследовательский совет). 2012