The 854th Chemical Company was activated 1 May 1942 at Fort George Wright in Spokane, Washington, under the command of Captain John G. Harsch. Second Lieutenant Victor A. Ryan assumed command in August of that year and moved the company to Merced, California, and later to Reno Army Air Base (now Reno Stead Airport). There were two more changes of command before the unit boarded the RMS Queen Mary on 1 June 1943 bound for Greenock, Scotland. Upon arrival on 6 June 1943, the organization proceeded to AAF Station 110, Polebrook. The company was then divided into two detachments, one remaining at Polebrook and the other moving to Grafton Underwood. Lieutenant Paul W. Simpson assumed command of Detachment "A," the segment at Grafton.
The primary assignment of the company was handling and filling chemical weapons in protective clothing along with operating the station decontamination equipment in case of chemical attack. The CWC was assigned to the 443rd Sub Depot at Grafton Underwood but group headquarters exercised indirect daily control. There were 67 personnel assigned to the company including 65 Enlisted Men and two Officers.
In England, inasmuch as they never had to perform the function for which they were intended, chemical warfare, the CWC's primary job focused on ordnance handling. The CWC worked out of the bomb dump filling napalm bombs and sky-markers with chemicals. More often, company personnel assembled incendiary bomb clusters. The CWC performed this task due to the highly volatile properties of the early magnesium incendiaries used. The loading of incendiaries and sky-markers was the primary duty of the chemical company.