A Ministry of Defence scientist died following a blast during top secret explosives tests which were inappropriately planned and appeared to be inadequately organised, an inquest jury has ruled.
Jurors made a number of criticisms of the trial in which Terry Jupp, 46, of Hatfield, Hertfordshire, was involved at a testing station near Shoeburyness, Essex, in August 2002, following an inquest in Southend, Essex.
They concluded that: planning and risk assessment had not been appropriate; a small scale test could have been carried out in advance; adequate regard was not paid to personal protective equipment; and they said communication and organisation at the trials appeared inadequate.
Mr Jupp, who worked for the MoD's Defence, Science and Technology Laboratory (DSTL), was involved in explosives tests aimed at combating terrorists in the months following the 9/11 attacks on New York, the inquest heard.
Much of the hearing was held in secret to prevent sensitive information falling into the hands of terrorists and the chemicals involved in the fatal test were referred to only as A, B and C.
Jurors heard Mr Jupp and colleagues had just finished mixing the three chemicals when the explosion occurred.
He suffered severe burns and died a week later in hospital.
The tests were part of joint experiments between British and American experts, the inquest heard.
One witness said the results could be "catastrophic" if information about the testing fell into the wrong hands.