Analytical work to identify gases used in enemy weapons was carried out in France and on the battlefield during the First World War, it was soon apparent that a need existed for an experimental site in the UK where the effective use of gas could be studied scientifically. After some initial trials at Cannock Chase - the War Department Experimental Ground was established at Porton, Wiltshire, in March 1916. An Experimental Company of the Royal Engineers [RE] was formed at Porton from Special Brigade personnel and - throughout the war - all experimental work was carried out by the Royal Engineers, assisted by an attached Royal Artillery [RA] Experimental Battery and officers of the Royal Army Medical Corps [RAMC].
In addition to the RE and RA units a Field Trials Department, a Chemical Laboratory, a Physiological Laboratory, a Meteorological Section and an Anti-Gas Laboratory were established.
Early work at Porton centred around the dissemination of gas from cylinders but first the Germans and then the Allies soon turned to the use of bursting munitions such as artillery shell, mortar bombs and grenades. Early in 1917 the trials range area was extended to provide for longer range artillery trials. At about the same time trials and proof of smoke weapons were added to the station's duties.
While these developments were taking place in the area of research and field trials many changes were also being made to the central administration of munitions supply. In June 1915 the Ministry of Munitions had been established and in December 1915 a Design Department was created within it. Among the Design Department's compass was responsibility for artillery design. The Director-General of Munitions Design was aided by the Ordnance Committee and a number of specialist committees, including a Chemical Advisory Committee and a Trench Warfare Committee. When the Munitions Council was formed in August 1917, a Design Group was created which incorporated the Design and Trench Warfare (Research) Departments. In October, responsibilities relating to gas and anti-gas research were transferred to the Ministry from the War Office. A Chemical Warfare Department was formed to deal with this work; it incorporated the Chemical Warfare Committee (as the Design Department's Chemical Advisory Committee was renamed) and some functions of the Trench Warfare (Research) Department. In April 1918 the Chemical Warfare Department was transferred from the Design Group to the Explosives Group of the Ministry. With the run-down of the Ministry of Munitions following the end of the war, the administration of chemical warfare matters passed back to the War Office, as a responsibility of the Master-General of the Ordnance.
When the war ended almost all work on chemical warfare virtually ceased, and most of Porton's staff were demobilized. In 1919, however, the Holland Committee recommended that research should continue on the means whereby the chemical industry might produce gases in any future war, and that there should be a factory for the production of those gases required for experimental work. A Chemical Warfare Research Department was established with Headquarters at the War Office in London, but also affiliated to the Admiralty and the Air Ministry. An advisory committee was also appointed. The Chemical Defence Research Establishment [CDRE] at Sutton Oak - which had been used for gas production during and following the war - assumed the functions of the factory, being constituted in 1925 as the Research Establishment, Sutton Oak. In the same year Porton - by then known as the Chemical Defence Experimental Station [CDES] was reorganized into six departments: Chemistry, Designs, Physiology, Physics, Meteorology and Technical.
On 1 August 1939 responsibility for the establishment passed to the Ministry of Supply and Portons efforts were transferred from defensive to offensive work. Although gas weapons were not used during the war, a number of areas of Porton's research did have substantial application: smoke was developed for screening purposes and coloured smoke for signalling.
An autonomous unit - the Biological Section - was established in 1940, independent for research purposes from CDES but relying on it for technical work, field trials and administration.
Other areas of research were nerve gases, biological warfare (leading to the constitution in July 1946 of the Microbiological Research Department [MRD]); field and ship gas detectors; new respirators to protect against highly toxic gases; microbiological studies; radioactive fall-out analyses on behalf of the Home Office; anti-riot grenades; radioactive decontamination; and on civil problems to assist non-government bodies. In 1957 the MRD became the Microbiological Research Establishment [MRE] and continued as such until its closure in 1979, and reemergence as the Public Health Laboratory Service Centre for Applied Microbiology and Research [CAMR].