CRYSTAL® STAIN BLOCK stain resist additive is an effective product for stain protection from food dyes. It helps prevent carpet fibers from being stained by wine, coffee, red soft drinks, fruit juices, and more. Simply add on bottle of CRYSTAL® STAIN BLOCK stain resist additive to one gallon of CRYSTAL DRY® solution for conference rooms, food service areas, lobbies, and any areas requiring extra stain protection. No VOCs and neutral pH. CRYSTAL® STAIN BLOCK is the only stain block to be approved by WoolSafe.