Jaeger Tri-Packs from Raschig USA are widely used as the packing in odor-control scrubbers. This packing, being almost spherical in shape, forms a random-packed bed. As a result, both the mass transfer and the chemistry used in the scrubber to absorb and destroy odors such as sewer gas are optimized. The odors are scrubbed in two stages — caustic only at a high pH to solubilize the H2S, then using caustic with bleach at a pH of approximately 9.5 to oxidize the H2S to sulfate. Typically in a two-stage system, the blowdown from the second stage is directed into the first stage sump in order to fully utilize the oxidizing chemical. The packs are NSF approved for potable water. 800/678-0345; www.raschig-usa.com.