BacShield (PROTECTANT) Inhibits Growth of Odor Causing Bacteria, Mold and Mildew Each gallon is a 21:1 concentrate, making 22 ready-to-use gallons. BacShield is a product of modified carbohydrates found in crab shells, a plentiful renewable resource. BacShield incorporates the environmentally derived antimicrobial properties of these crab shells into a treatment for textiles and surfaces. This product is perfect for HARSH Environments and outdoor surfaces like fences, sidewalks, roofs, vinyl...