Hydrofera Blue Classic Antibacterial Foam Dressing Heavy Drainage. A foam dressing made by preferentially binding two organic components, methylene blue and gentian violet to open-celled polyvinyl alcohol (PVA). Features: Broad-spectrum antibacterial protection, Rapid wicking and exudate retention, Assists in autolytic debridement, Resolution of epibole and flattening of wound edges, Non-cytotoxic, Compatible with enzymatic debriders and fibroblast growth factors, Helps maintain a moist wound environment.