When formulating cosmetic preservatives, personal care preservatives, industrial biocides, and household disinfectants, choosing the right antimicrobial agent is critical. CMIT/MIT (Methylchloroisothiazolinone/Methylisothiazolinone) and PHMB (Polyhexamethylene Biguanide) are two of the most commonly used preservatives and biocides in multiple industries.

But which one is better for your formulation? This article provides a detailed comparison of CMIT/MIT and PHMB, covering:
Antimicrobial efficacy (bacteria, fungi, viruses)
Regulatory compliance (EU, FDA, China)
Toxicity & skin safety
Best applications & industries
Cost-effectiveness

Read on to discover which preservative solution is best for your needs.

1. What Are CMIT/MIT and PHMB?

(1) CMIT/MIT (Methylchloroisothiazolinone/Methylisothiazolinone)

• Broad-spectrum antimicrobial activity against bacteria, fungi, and yeast

• Highly effective in low concentrations

• Water-soluble and commonly used in aqueous formulations

Applications:

• Personal care products: Shampoos, conditioners, body washes (mainly rinse-off)

• Household products: Detergents, surface cleaners, fabric softeners

• Industrial applications: Paints, adhesives, and cooling water treatments

Regulatory Restrictions:

• EU (Cosmetic Regulation 1223/2009): Banned in leave-on cosmetics; allowed in rinse-off products up to 15 ppm (0.0015%)

• USA (FDA & CIR guidelines): Not banned, but usage levels depend on product type

• China: Follows similar regulations as the EU, banning it in leave-on formulations

• Other regions: Many countries have adopted similar restrictions due to skin sensitization concerns

(2) PHMB (Polyhexamethylene Biguanide)

Low-toxicity, non-irritating preservative safe for sensitive skin formulations
Strong antibacterial and antiviral properties, widely used in medical disinfection
Excellent water solubility, but less heat-resistant than CMIT/MIT

Common Applications:

• Cosmetic & personal care products: Skincare, facial creams, wet wipes
• Medical disinfection: Wound care, skin antiseptics, eye drops
• Water treatment: Swimming pools, industrial water disinfection

Regulatory Restrictions:

• EU limits PHMB to 0.1% in personal care products
• Approved for use in medical and disinfectant applications

2. CMIT/MIT vs. PHMB: Key Comparison

Criteria	CMIT/MIT	PHMB
Antimicrobial Efficacy	Effective against bacteria, fungi, yeast	Strong antibacterial and antiviral properties, less effective on fungi
Skin Sensitivity & Toxicity	Potential skin irritant, banned in EU leave-on products	Low irritation, safe for sensitive skin
Regulatory Compliance	Restricted in EU for leave-on cosmetics	Allowed in skincare, medical, and water treatment
Best for Personal Care?	Shampoos, soaps, detergents (rinse-off)	Lotions, creams, wet wipes (leave-on & sensitive skin)
Best for Industrial Use?	Paints, coatings, paper, adhesives	Swimming pools, medical disinfection
Water Solubility	Good for water-based formulations	Highly water-soluble, but heat-sensitive
pH Stability	2–9 (Stable in acidic conditions)	4–10 (Better in neutral environments)
Cost	Cost-effective	More expensive, but safer

3. Which Preservative Is Right for Your Product?

Choose CMIT/MIT if:
Your product is a rinse-off personal care product (shampoo, body wash, detergent)
You need cost-effective industrial biocides for paint, coatings, adhesives
Your formulation requires strong fungal and bacterial protection

Choose PHMB if:
Your product is a leave-on skincare product, wet wipes, or medical disinfectant
You need a preservative with low irritation, safe for sensitive skin
Your product requires antibacterial and antiviral efficacy

4. Can CMIT/MIT and PHMB Be Used Together?

Yes, but careful formulation adjustments are required.

• CMIT/MIT is strong against bacteria & fungi but has potential irritation risks
• PHMB is safer for sensitive skin but may not fully cover fungal contamination
• Combination use requires pH stability testing to optimize antimicrobial performance 

For custom preservative system formulations, contact us for expert guidance.

5. Conclusion: CMIT/MIT vs. PHMB – Which One Should You Choose?

If you prioritize cost and broad-spectrum efficacy → Choose CMIT/MIT
If you need safety for sensitive skin & medical applications → Choose PHMB
If you require a hybrid solution → Consider a combination preservative system

Looking for high-quality CMIT/MIT or PHMB preservatives?
We are a leading supplier of cosmetic preservatives and industrial biocides.
Contact us today for bulk pricing and formulation guidance!

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