DELTA DUST CAN"T BE SHIPPED TO NY OR CT Active Ingredient in Delta Dust is Deltamethrin. Delta Dust is a long term residual dust, killing crawling insects. Treats: For up to 8 months when left undisturbed. Odorless, non staining.Does not clump or absorb moisture. How do I properly use the hand duster? Remove black rubber cap from top of duster. The duster should be filled only halfway - no more than two-thirds full. This allows for adequate air space to create the desired air/dust mixture prior to application. If there is too much dust in the duster, clumps of dust on treated surfaces may result, leading to over application of the product and messy spills. Between each squeeze, the duster should be shaken slightly to get dust floating inside the duster. When applying dust , gently squeeze the duster to ensure the application of very thin layers of dust. When dusting correctly, you should barely be able to see the dust emerging from the tip of the duster. Before relaxing your grip on the duster, pull it away from the surface or crack you are treating to prevent sucking up lint, moisture or debris. Small amounts of these items will eventually cause lumping and/or clogging of the duster. In the event that the nozzle becomes clogged, you may unscrew the rod from the rear of the nozzle and insert it into the nozzle to break up any clogs.