Part III - Historical Survey of the Porton Down Service Volunteer ...

a. Based on Porton work reported in June 1949 [24], it was decided in October
1949 [25, 26] that GA was of little value. GD was found to be the most toxic of
the G series but was ruled out because the raw material (pinacolyl alcohol)
necessary for its production was not available in any quantity. GB was generally
preferable to GE but GF showed some promise as a persistent agent that
attacked through the skin and it was decided that it should be examined further.
b. A further assessment of nerve gases published by Porton in August 1950 [27]
concluded that, from a toxicological aspect, GB is "in every way superior to" GE
as a chemical warfare agent. GD and GF were found to be highly toxic through
the skin but were thought to be of too low a volatility to be used in HE/chemical
munitions. The possibility of using GD and GF as an anti-personnel spray was
considered.
c. In December 1950 the War Office was noted to have "a definite aversion to
persistence" [28]. This ruled out GD and GF which evaporated much more
slowly than GB. In May 1951 it was decided that GB would be the agent used in
UK offensive weapons and would be produced on a large scale [29].
8.3.2. Preparatory work at Porton
Plans for a systematic physiological investigation of the G agents were produced by Porton
[30, 31]. From 1946 to 1948 assessments of nerve agents with animals were undertaken,
which allowed the members of the G series to be compared and paved the way for human
studies.
The remaining preparatory work immediately after the war saw the development of new
experimental techniques and equipment. Nerve agent studies required a supply of samples
of the G agents and the decision to develop weapons meant larger quantities of nerve agents
needed to be produced. Porton, therefore, studied ways of manufacturing G agents.
Existing experimental techniques and equipment at Porton had been developed largely for
mustard gas work. Some were unsuitable or inadequate for studies with nerve agents.
Apparatus for eye studies and techniques for chamber tests were needed [31]. Various
techniques and equipment were developed immediately after the war: new gas chambers
were fitted and calibrated, techniques for measuring the concentration of G agents were
developed, and simulants for G agents were sought.
A technique was developed to measure and compare the effects of G agents. It was thought
in 1946 that measuring ChE activity, and the degree to which it was inhibited by G agents,
would be a useful means of comparing nerve gases [31]. Measurement was a complicated
process and several methods were available at the time. Apparatus was set up to measure
ChE activity by the Warburg method [32] in 1946.
The role of ChE as a detector of nerve gases, an aid to detecting nerve agent poisoning and
a means of predicting lethal doses in man is described at Annex C.
8.4. Human studies with vapour
8.4.1. Detection: chamber studies
The possibility of recognising the presence of nerve gas vapour by a combination of smell,
chest and eye effects was recognised in the plans for nerve agent work produced for CDAB
by Porton in December 1946 [30]. The concern was whether men would recognise these
effects before a dangerous dose was inhaled.
A series of studies was conducted in late April 1948 [16, 33] in which sixteen volunteers from
among Porton staff [16] were exposed, with eyes protected by goggles, to GB, GD and GE.
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