Polyhexamethylene Biguanide (PHMB) Treatment
topic
Polyhexamethylene biguanide (PHMB, CAS 32289-58-0, MW 2,000–3,000 Da) is applied to textiles at 0.5–2.0% owf via exhaustion (pH 5.5–6.5, 40–60°C, 30 min) or pad-dry-cure (120°C). Cationic biguanide groups bind electrostatically to anionic cellulose and wool surfaces with high substantivity. Bactericidal mechanism involves irreversible disruption of cytoplasmic membranes at MIC of 1–5 µg/mL for most pathogens. Efficacy of 3–5 log reduction (AATCC TM100) persists through 30–50 wash cycles at 60°C. Active against MRSA, VRE, and Candida. EU BPR under active review for PT9 (fiber preservatives); current use permitted pending review outcome. Cost of $0.15–0.35/m² supports use in hospital textiles and wound dressings.
Role
Leading synthetic polymeric biocide for durable hospital textile finishing, providing high-temperature wash-fast antimicrobial protection against healthcare-associated pathogens in a single-application, low-cost treatment system.