Benzalkonium Chloride (BAC) CAS 63449-41-2

Benzalkonium Chloride (BAC) – Broad-Spectrum Disinfectant and Preservative

Basic Information

• CAS Number: 63449-41-2

• Chemical Class: Quaternary ammonium compounds (alkyl dimethyl benzyl ammonium chlorides)

• Appearance: White to yellowish powder or gelatinous mass (typically supplied as aqueous solution)

• Solubility: Soluble in water, alcohol, and acetone

• pH: 5–8 (in solution)

Overview
Benzalkonium chloride (BAC) is a mixture of alkyl dimethyl benzyl ammonium chlorides with varying alkyl chain lengths (typically C₈–C₁₈). It is one of the most widely used quaternary ammonium compounds in disinfectant and preservative applications due to its broad-spectrum antimicrobial activity against bacteria, fungi, and some viruses. Its cationic nature allows strong adsorption to negatively charged surfaces, including microbial cell membranes and skin.

Applications

• Pharmaceuticals: Used as a preservative in ophthalmic solutions (eye drops), nasal sprays, and injectable formulations.

• Cosmetics: Acts as a preservative and antimicrobial agent in creams, lotions, shampoos, and contact lens solutions.

• Household and industrial cleaning: Disinfectant in surface cleaners, fabric softeners, and sanitizers.

• Healthcare: Used in antiseptic solutions, hand sanitizers, and instrument disinfection.

• Water treatment: Algaecide and biocide in swimming pools and industrial water systems.

Mechanism of Action
BAC disrupts microbial cell membranes through electrostatic interaction with negatively charged lipid components, causing leakage of intracellular contents and cell lysis. It also denatures proteins and enzymes, contributing to its rapid bactericidal and fungicidal effects.

Advantages

• Broad-spectrum efficacy against gram-positive and gram-negative bacteria, fungi, and enveloped viruses.

• Effective at low concentrations (0.01–0.1%).

• Good stability and long shelf life.

• Compatible with many formulation ingredients.

Precautions and Limitations

• May cause skin, eye, and respiratory irritation at higher concentrations.

• Not recommended for use on mucosal tissues in concentrations above 0.02% due to cytotoxicity.

• Incompatible with anionic surfactants (forms precipitates).

• Prolonged use in ophthalmic products may cause corneal damage; use with caution.

• Toxicity to aquatic organisms – avoid environmental release.

Handling and Storage

• Store in a cool, dry, well-ventilated area, away from light and moisture.

• Keep containers tightly sealed to prevent contamination and degradation.

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

• Avoid contact with skin and eyes; rinse thoroughly with water if contact occurs.

Packaging
Available in various concentrations (50%, 80% solutions) and packaging sizes (1 L, 5 L, 25 L, 200 L drums). Custom packaging upon request.

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