Chemical work at Edgewood Arsenal of Aberdeen Proving Ground began June 18, 1918. Later referred to as Edgewood Area, the facility was established in November 1917 and construction of the laboratory began in April 1918.
It provided chemical production and artillery shell filling facilities to respond to the chemical weapons that were being used in Europe during World War I. The main chemicals produced were phosgene, chloropicrin and mustard.
Source: Harford County Directory and GlobalSecurity.org