Didecyldimethylammonium Chloride (DDAC)

Didecyldimethylammonium Chloride (DDAC) – Broad-Spectrum Quaternary Ammonium Disinfectant

Basic Information

• CAS Number: 7173-51-5

• Molecular Formula: C₂₂H₄₈ClN

• Molecular Weight: 362.08 g/mol

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

• Solubility: Soluble in water, alcohols, and polar solvents

• pH (as supplied): Typically 5–9 (neutral to slightly alkaline)

Overview
Didecyldimethylammonium chloride (DDAC) is a widely used quaternary ammonium compound (QAC) recognized for its broad-spectrum antimicrobial activity. It is effective against bacteria (both Gram-positive and Gram-negative), fungi, yeasts, and enveloped viruses. Its cationic nature allows strong adsorption to negatively charged microbial surfaces, leading to membrane disruption and cell death. DDAC is employed in healthcare, food processing, agriculture, and household sanitation.

Mechanism of Action
DDAC disrupts microbial cell membranes through electrostatic interaction with phospholipid bilayers, causing leakage of intracellular contents. It also denatures proteins and enzymes, contributing to rapid bactericidal, fungicidal, and virucidal effects. Its efficacy is enhanced when combined with alcohols, nonionic surfactants, or oxidizing agents.

Applications

• Healthcare: Surface disinfectants, instrument sterilization, and hand sanitizers.

• Food industry: Disinfection of food contact surfaces, equipment, and processing areas.

• Agriculture: Used as a biocide in animal husbandry and crop protection.

• Household: Disinfectant sprays, wipes, and cleaning solutions.

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

• Industrial: Antimicrobial additive in paints, coatings, and textiles.

Key Benefits

• Broad-spectrum activity at low concentrations (0.05–0.5%).

• Effective against biofilm-forming microorganisms.

• Good compatibility with nonionic and cationic surfactants.

• Stable over a wide pH range (5–9).

• Long-lasting residual antimicrobial effect.

• Cost-effective compared to many alternative biocides.

Synergy with Other Ingredients

• Alcohols: Ethanol or isopropanol improves solubility and enhances rapid kill.

• Peroxides: Low concentrations of hydrogen peroxide boost bactericidal activity, but stability must be controlled.

• Nonionic surfactants: Improve wetting, reduce surface tension, and enhance penetration to pathogens.

Safety and Precautions

• May cause skin and eye irritation at high concentrations; use appropriate PPE (gloves, goggles).

• Incompatible with anionic surfactants (forms precipitates).

• Toxic to aquatic organisms; avoid environmental release.

• Handle with adequate ventilation; avoid inhalation of aerosols.

• Follow recommended exposure limits and safety guidelines.

Handling and Storage

• Store in a cool, dry, well-ventilated area, away from strong oxidizers and acids.

• Keep containers tightly sealed to prevent contamination.

• Shelf life: typically 24 months under recommended conditions.

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

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