Chlorphenesin CAS 104-29-0

1. Physical and Chemical Properties

Chlorphenesin appears as a white crystalline powder. For a formulator, understanding its solubility profile is key to using it successfully.

2. Applications: The “Booster” Effect

Chlorphenesin is rarely a solo act. Its strength lies in its ability to boost the efficacy of other preservatives.

• Skincare (Creams, Lotions, Serums): It is a favorite in facial moisturizers because it is non-irritating and provides excellent protection against fungi and yeast, which are common spoilers in water-heavy formulas.
• Color Cosmetics: Widely used in mascara and liquid foundations where preventing mold growth is critical.
• Facial Masks: In wet sheet masks, where the water activity is very high, Chlorphenesin is often paired with Phenoxyethanol to ensure broad-spectrum protection without stinging the user’s face.
• Deodorants: Due to its antimicrobial properties, it helps control odor-causing bacteria.

3. A Formulator’s Guide: Overcoming Solubility

If there is one complaint about Chlorphenesin, it is that it can be “finicky” to dissolve. Here is how seasoned chemists handle it:

1. Heat is your friend: While it has low solubility in cold water, it dissolves readily in water heated to 50°C – 60°C.
2. Pre-mix in Glycols: The best practice is to pre-dissolve Chlorphenesin in a solvent like Butylene Glycol or Propylene Glycol before adding it to the water phase. This ensures a crystal-clear solution and prevents the powder from precipitating out later.
3. The “Synergy” Blend: It works exceptionally well when combined with Ethylhexylglycerin or Phenoxyethanol. This combination allows you to lower the total preservative load while maintaining a “Class A” preservation challenge test result.

4. Regulatory & Safety Profile

Chlorphenesin is valued because it has a long history of safe use.

• Global Compliance: It is approved for use in the USA, EU, China, and Japan.
• Concentration Limits:
  • EU & China: Maximum authorized concentration is 0.3%.
  • Japan: Maximum authorized concentration is 0.3%.
• Safety: It is considered non-sensitizing and non-toxic at approved levels. It does not contain formaldehyde and is not a paraben.

5. Safety Precautions for Handling

While safe in the finished cream, the raw powder requires standard chemical hygiene:

• Dust Hazard: The fine powder can irritate the respiratory tract. Workers should wear N95 dust masks during weighing and mixing.
• Eye Contact: Can cause irritation. Safety goggles are mandatory.
• Ingestion: Harmful if swallowed in large quantities (due to its muscle relaxant history).

6. Storage Conditions

Proper storage is essential to prevent caking and maintain flowability.

• Moisture Control: Chlorphenesin is stable, but high humidity can cause the powder to clump. Keep containers tightly sealed.
• Packaging: typically shipped in 25kg fiber drums with double PE inner liners.
• Temperature: Store in a cool, dry place away from direct sunlight and strong oxidizing agents.