Benzalkonium Chloride

INCI: Benzalkonium Chloride

Benzalkonium chloride (BKC) is a quaternary ammonium compound (a “quat”) used as:

• Preservative
• Antimicrobial agent
• Disinfectant
• Cationic surfactant
• It is very effective against:
• Bacteria (Gram+ and Gram–)
• Fungi
• Some viruses

🔹 Key Functions in Cosmetics & Personal Care

1. Antimicrobial / Preservative

• Controls microbial growth in:
• Lotions
• Creams
• Wet wipes
• Rinse-off products
• Some leave-on products (within limits)

2. Disinfectant (High Concentration)

Used in:

• Hand sanitizers (non-alcohol types)
• Surface sprays
• Antiseptic solutions
• Medical wipes

3. Cationic Surfactant

Provides mild conditioning effects in:

• Hair products
• Skin cleansers
• Some ophthalmic products (at very low levels)

🔹 Usage Levels

In Cosmetics

• 0.05 – 0.1% typical
• Often used at 0.05% in lotions & creams
• Max allowed in rinse-off products: 0.1%

In Antiseptic / Disinfectant Products

• 0.1 – 0.2% → hand sanitizers
• 0.13% → common hand disinfectant strength
• Up to 0.5% in some medical antiseptics

🔹 Solubility & Compatibility

Solubility

• Water soluble
• Alcohol soluble
• Works well in water-based systems

Compatible With

• Cationic surfactants
• Amphoteric surfactants
• Many humectants
• Alcohols
• Avoid Mixing With
  ❌ Anionic surfactants (SLES, SLS, AOS, etc.) → they deactivate BKC
  ❌ Harsh acids & strong oxidizers → instability
  ❌ High concentrations of clays → adsorption reduces efficacy
  To preserve activity, pair with:
  Nonionic surfactants
  Cationic emulsifiers

🔹 Formulation Considerations

✔ Add during the water phase or cool-down

Avoid high heat for long durations.

✔ Works well with chelators (EDTA)

Boosts antimicrobial efficacy.

✔ pH Range

Best at: pH 5–10

Below pH 4, stability decreases.

✔ Skin Sensitivity

At high concentrations, it may:

• Be irritating
• Cause redness
• Dry the skin
• But at cosmetic levels (0.05–0.1%), it is generally well tolerated.

Widely used in medical and personal care industries

🔹 Common Applications

Cosmetics & Personal Care

• Wet wipes (0.05–0.1%)
• Facial cleansers
• Deodorants
• Pharmaceutical / Medical
• Antiseptic wipes
• Eye drops (0.004–0.02%)
• Nasal sprays
• Mouthwashes
• Household
• Surface disinfectants
• Fabric softeners
• Sanitizer sprays