In a pyrotechnic facility, a fire followed by an explosion ripped through a warehouse storing anti-hail rockets and rocket motors charged with black powder. The effects of this blast and projected debris were readily observable. 2 employees were slightly injured and the warehouse entirely destroyed. Property damage and production losses amounted to 7 M francs. An incompatibility between the nitrate explosive components (ammonium nitrate and pentolite) and impurities introduced during a splitting step (intermediate container used in the operation inadequately cleaned) caused this accident. Regarding these aspects, pyrotechnic experts generally recommend a careful cleaning of all tooling, yet still prefer (whenever possible) the use of tools dedicated to each single product.