Polyhexamethylene Biguanide (PHMB) CAS 27083-27-8

Polyhexamethylene Biguanide (PHMB) – Polymeric Disinfectant with Prolonged Antimicrobial Activity

Basic Information

• CAS Number: 27083-27-8

• Chemical Class: Polymeric biguanide (guanidine polymer)

• Appearance: Colorless to pale yellow liquid (typically supplied as aqueous solution)

• Solubility: Soluble in water and polar solvents

• pH (1% solution): Typically 4.0–7.0

• Molecular Weight: Variable (polymeric, typically 1,000–5,000 Da)

Overview
Polyhexamethylene biguanide (PHMB) is a high‑molecular‑weight cationic polymeric biocide with broad‑spectrum antimicrobial activity. It is widely used in water treatment, healthcare, industrial cleaning, and personal care products. Its prolonged action and low cytotoxicity make it suitable for applications where long‑term microbial control is required without harming human cells or tissues.

Applications

• Water treatment: Used as a disinfectant in swimming pools, cooling towers, and industrial water systems to control algae, bacteria, and biofilm.

• Medical waste treatment: Applied in the sterilization of medical waste and contaminated equipment.

• Equipment cleaning: Used as a disinfectant in food processing, pharmaceutical manufacturing, and laboratory equipment.

• Healthcare: Employed as an antiseptic for wound care, contact lens solutions, and as a preservative in ophthalmic and topical formulations.

• Textile and paper: Used as a biocide to prevent microbial growth in textiles and paper products.

• Cosmetics: Added to personal care products (shampoos, lotions) as a preservative and antimicrobial agent.

Mechanism of Action
PHMB acts through a cationic mechanism: its positively charged biguanide groups adsorb to negatively charged microbial cell membranes, disrupting membrane integrity and causing leakage of intracellular components. This leads to rapid cell death. Additionally, PHMB can penetrate biofilms, ensuring effective control even in challenging environments.

Key Benefits

• Broad‑spectrum activity against bacteria, fungi, algae, and some viruses.

• Prolonged antimicrobial action – provides residual protection.

• Low cytotoxicity – safe for use on skin and mucous membranes at recommended concentrations.

• Compatible with many biomaterials and formulation ingredients.

• Effective in hard water and over a wide pH range.

• Non‑corrosive and stable under typical storage conditions.

Safety and Regulatory

• Generally recognized as safe (GRAS) for use in food‑contact and water treatment applications.

• Low acute toxicity; however, avoid inhalation and ingestion.

• May cause mild eye and skin irritation at high concentrations.

• Use appropriate personal protective equipment (gloves, safety goggles) during handling.

• Refer to Safety Data Sheet (SDS) for detailed safety information.

Handling and Storage

• Store in a cool, dry, well‑ventilated area, away from strong oxidizers and reducing agents.

• Keep containers tightly sealed to prevent contamination and evaporation.

• Avoid contact with anionic surfactants (may form precipitates).

• Use standard chemical handling precautions.

Packaging
Available in 1 L, 5 L, 25 L, and 200 L drums, and in bulk quantities (IBC containers). Custom packaging upon request.

Quality Assurance
Each batch is tested for active content, pH, and antimicrobial efficacy to ensure consistent performance.