PCMC - Chlorocresol

1. Product Core Information

Product Name4-Chloro-3-methylphenol

Common Name/SynonymPCMC / Chlorocresol

Other Namesp-Chloro-m-cresol, 4-Chloro-m-cresol, Chlorocresol

Chemical Name4-Chloro-3-methylphenol

IUPAC Name4-Chloro-3-methylphenol; p-chloro-m-cresol

Molecular FormulaC₇H₇ClO

Molecular Weight142.58 g/mol

CAS Number59-50-7

EC Number200-431-6

2. Product Characteristics

Property	Specification
Appearance	White to off-white crystalline powder or crystalline mass with characteristic phenolic odor
Antimicrobial Spectrum	Broad-spectrum; highly effective against Gram-positive bacteria, Gram-negative bacteria, molds, and yeasts
Safety Profile	Low toxicity, non-irritating; negative in skin irritation tests; EU BPC approved for human hygiene disinfectants
Stability	Good heat resistance; stable at pH 1-14; steam-volatile
Solubility	Slightly soluble in water (4 g/L at 20°C); readily soluble in ethanol, ether, acetone, chloroform, and alkaline solutions

Physical & Chemical Data:

Boiling Point: 235°C (atmospheric pressure) / 236°C
Melting Point: 63-67°C (64-66°C)
Flash Point: 118°C
Density: 1.37 g/mL (20°C)
Vapor Pressure (20°C): 0.08 hPa / 5.00×10⁻² mmHg
pKa: 9.55-9.6
Log Kow: 3.1

3. Quality Standards

Parameter	Specification	Test Method
Appearance	White or off-white crystalline powder or crystalline mass	Visual
Odor	Characteristic phenolic odor	Organoleptic
Purity (GC)	≥98.0% (Technical) / 98.0%-101.0% (Pharmacopoeia Grade)	GC
Melting Range	63°C-67°C (64-66°C)	Capillary Method
Acidity	Not more than 0.2 mL of 0.01 mol/L NaOH (methyl red indicator)	Acid-Base Titration
Clarity and Color of Solution	Clear and colorless; if colored, not darker than reference solution Orange-2	Colorimetric
Residue on Ignition	≤0.2%	Gravimetric
Acid Value	4.0-6.0	Titration
Identification	IR spectrum matches reference; blue-violet color with ferric chloride test; white precipitate with bromine test	IR Spectroscopy, Color Reaction

Note: Pharmacopoeia grade complies with Chinese Pharmacopoeia 2020 Edition Part IV. Technical grade meets enterprise standards.

4. Antimicrobial Activity (MIC Values)

Microorganism	MIC (mg/L)	Microorganism	MIC (mg/L)
Aspergillus niger	50	Chaetomium globosum	50
Aspergillus flavus	50	Bacillus subtilis	50
Aspergillus versicolor	50	Bacillus megaterium	50
Penicillium citrinum	50	Escherichia coli	250
Paecilomyces variotii	10	Pseudomonas fluorescens	100
Cladosporium cladosporioides	50	Staphylococcus aureus	50

Note: PCMC shows excellent inhibition against Paecilomyces variotii with MIC of only 10 mg/L

5. Applications

5.1 Personal Care & Cosmetics

Skincare: Face creams, lotions, baby care products (0.1%-0.2% concentration)
Hair & Body Care: Shampoos, shower gels, disinfectant soaps, hand washes
Color Cosmetics: Lipsticks, eye shadows, foundations
Maximum Permitted Concentration: 0.2% (w/w); prohibited for products contacting mucous membranes

5.2 Pharmaceutical Applications

Pharmaceutical Preservative: Injections, eye drops, nasal drops, and other liquid preparations (0.1%-0.2%)
Veterinary Medicine: Oral/injectable veterinary drugs and topical formulations
Medical Device Disinfection: Surgical instruments and medical supplies
Skin Care: Wound cleansing preparations, antiseptic products, nasal care vaporizers

5.3 Industrial Preservation

Metalworking Fluids: Cutting fluids and coolants (prevents microbial degradation and extends service life)
Coatings & Paints: Antifungal and antibacterial properties to prevent mold on paint films
Adhesives & Inks: Prevents colloidal contamination
Leather Processing: Antifungal and antibacterial treatment
Wood Protection: Preservative and insect-resistant treatment
Textiles & Paper: Fabric mildew prevention and pulp preservation
Rubber Industry: Antioxidant
Concrete & Building Materials: Additive preservation

5.4 Agriculture & Animal Husbandry

Environmental Disinfection: Poultry and livestock farm disinfection
Hospital & Household: Environmental cleaning and disinfection

6. Regulatory Compliance & Safety

Certification/Regulation	Details
EU BPC Approval	Approved in 2016 as active substance for PT-1, PT-2, PT-3, PT-6, and PT-13 biocidal products; approval valid until May 1, 2028
Chinese Pharmacopoeia	Listed in Chinese Pharmacopoeia 2020 Edition Part IV as pharmaceutical excipient preservative
Cosmetics Regulation	Technical Safety Standard for Cosmetics 2015 Edition: Maximum concentration 0.2%, prohibited for mucous membrane contact
US EPA	Registered as antimicrobial pesticide; currently under re-registration process

Toxicity Data:

Endpoint	Value
Acute Oral LD₅₀ (Rat)	1830-2810 mg/kg (Low toxicity)
Acute Dermal LD₅₀ (Rat)	>2000 mg/kg
Skin Irritation (Rabbit)	Non-irritating
Eye Irritation (Rabbit)	Corrosive (protective measures required)
Sensitization	Skin sensitizer Category 1B
Aquatic Toxicity	Harmful to aquatic organisms (WGK 2)

7. Usage Guidelines & Formulation Recommendations

Solubilization:

Readily soluble in ethanol, ether, acetone, and other organic solvents; dissolve in organic solvent first, then add to aqueous phase
Solubility significantly increases under alkaline conditions (320 g/L in 10% sodium hydroxide solution)
Fully compatible with oils and fats; suitable for oil-based systems

Recommended Dosage:

Personal Care Products: 0.1%-0.2%
Pharmaceutical Preparations: 0.1%-0.2%
Industrial Preservation: 0.5%-5.0% (adjust according to specific application)

8. Packaging & Storage

Packaging: 25kg fiber drum (PE-lined) / 20kg iron drum / 1kg aluminum foil bag

Storage: Cool, dry place (≤25°C); sealed, protected from light; away from strong acids, strong bases, and oxidizers

Shelf Life: 36 months (unopened)

Transport: Handle as general chemical; load/unload carefully to prevent package damage

9. Key Advantages

Long History: Classic preservative with extensive human use history and comprehensive safety data
Broad Spectrum & High Efficacy: Strong inhibitory effects on bacteria, molds, and yeasts with low MIC values
Complete Regulatory Status: Multi-use approval under EU BPC; listed in Chinese Pharmacopoeia; recognized in major global markets
Wide Applications: Covers pharmaceuticals, personal care, industry, and agriculture
High Stability: Stable across pH 1-14; compatible with various formulations
Cost-Effective: Lower molecular weight compared to PCMX and DCMX; lower cost per unit antimicrobial activity

PCMC (4-Chloro-3-methylphenol)