Vacuum Collection. Vacuum (aspirator) systems with a wet-type collector that moistens explosive dust close to the point of origin and keeps it wet until the dust is removed for disposal are preferred. However, some dusts, (e.g., Explosive D) should be collected in a dry-type system.
5.47.1. Vacuum systems must be arranged so each type of explosive is collected separately or so dissimilar hazards (for example, black powder with lead azide) are not mixed.
5.47.2. Provision should be made for the proper liberation of gases that may be formed in a vacuum system.
5.47.3. Vacuum systems used to collect more sensitive explosives (such as black powder, lead azide, mercury fulminate, tracer, igniter, incendiary compositions, and pyrotechnic materials) should be used only for operations with fuzes, detonators, small arms ammunition, and black powder igniters. Wet-type collectors are required, with a compatible wetting agent close to the point of intake.