Objectives of this project were (1) to determine the effects of blasts on filtration devices and typical gas-cleaning systems in the 3-and 1-psi overpressure range, (2) to measure dust dislodged from AEC filters and dry plates by blast and reentrained in reverse-flow air, (3) to determine the pressure attenuation and dust recovery characteristics of typical wire mesh viscous filters and dry Fiberglas filters, (4) to determine the natural damping effect of duct work and stacks, and (5) to compare field and laboratory data to determine if present and future laboratory tests can be extrapolated to predict field conditions. Test results showed no damage to AEC filters and only minor damage to Fiberglas filters. Total reentrainment ranged from 73 per cent of total AFC filter loading (3.4-psi area) to 53 per cent (l,5 psi). Dry plates lost 95 per cent of their original dust holding. Prefilters recovered approximately 30 per cent of dust dislodged from AEC filters. Wire mesh afterfilters reduced dust loss from 53 to 4.5 per cent. Field tests appear to agree with laboratory studies and indicate that future tests can be performed successfully in laboratory shock tubes.