Increasing universal understanding — the additional symbol
The trefoil was initially created to mark radioactive material used in controlled environments, such as laboratories, where people who had access to the material would already know its meaning. Over the years, the use of radioactive material in medicine, agriculture and industry has become more widespread.
Consequently, radioactive material or radiation emitting devices can be found not just in research laboratories and nuclear power plants, but also in hospitals, as well as in industrial equipment, for example in X ray security equipment used in airports.
In the past, due to lack of knowledge people would endanger themselves and others because they did not understand the meaning of the symbol. For example, in a few instances around the world, scrap metal collectors and construction workers were exposed to radiation by taking and handling misplaced radioactive sources they had found in scrap yards or on construction sites, because they did not understand the ‘warning signage’.
To improve nuclear safety and security, in 2007 the IAEA and the International Organization for Standardization (ISO) introduced a supplementary symbol designed to be universally understood as ‘Danger — Run Away — Do Not Touch!’.
To determine which symbol would better convey the radiation risk to the public, the IAEA conducted a survey covering 11 countries in different parts of the world. The result was the ‘Ionizing-radiation warning — Supplementary Symbol’, a red triangle that depicts radiation waves, a skull and a running human figure. It was launched as a supplement to the more commonly used ionizing radiation symbol with the intention of further reducing the possibility of accidental exposure to ionizing radiation.
