Chemical Corps affiliation with the corps. The Chemical Corps branch insignia consists of a cobalt blue, enamel benzene ring superimposed over two crossed gold retorts. The branch insignia, which was adopted in 1918 by the fledgling Chemical Service, measures .5 inches in height by 1.81 inches in width. Crossed shells with a dragon head was also commonly used in France for the Chemical service. The Chemical Warfare Service approved the insignia in 1921 and in 1924 the ring adopted the cobalt blue enamel. When the Chemical Warfare Service changed designations to the Chemical Corps in 1946 the symbol was retained. The regimental
CB military symbol or have been, used by the United States: Material Testing Program EA (Edgewood Arsenal) numbers:<br> CB military symbol Chemical, biological (CB) — and sometimes radiological — warfare agents were assigned what is termed a military symbol by the U.S. military until the American chemical and biological weapons programs were terminated (in 1990 and 1969, respectively). Military symbols applied to the CB agent fill, and not to the entire weapon. A chemical or biological weapon designation would be, for example, "Aero-14/B", which could be filled with GB, VX, TGB, or with a biological modification kit – OU, NU, UL, etc. A