Analysis of information sources in references of the Wikipedia article "Hazard symbol" in English language version.
(a) warning sign 'Harmful or irritant material' is deleted.
The three-bladed radiation warning symbol, as we currently know it, was "doodled" out at the University of California Radiation Laboratory in Berkeley sometime in 1946 by a small group of people.
The three-bladed radiation warning symbol, as we currently know it, was "doodled" out at the University of California Radiation Laboratory in Berkeley sometime in 1946 by a small group of people.
(a) warning sign 'Harmful or irritant material' is deleted.