The Dorset Biological Warfare Experiments were a series of experiments conducted between 1953 and 1975 to determine the extent to which a single ship or aircraft could dispense biological warfare agents over the United Kingdom. The tests between 1971–1975 were known as the DICE trials. The tests were conducted by scientists from Porton Down, initially using Zinc cadmium sulfide (ZnCds) as a simulated agent. Early results clearly showed that one aircraft flying along the coast while spraying its agent could contaminate a target over 100 miles away, over an area of 10,000 square miles. This method of Biological warfare attack and the test program to study it was known as the Large Area Coverage (LAC) concept.
In the early 1960s, Porton Down was asked to expand the scope of their tests to determine if using a live bacteria instead of ZnCds would significantly alter the results. Scientists from Microbiological Research Establishment at Porton Down selected South Dorset as the site for this next phase of testing, with Bacillus subtilis (also known as Bacillus globigii or BG) selected as the test agent.