Methyl Paraben

Product Details

CasNo： 99-76-3

MF： C8H8O3

Appearance： powder

Delivery Time： 15 days

Packing： 25kg/bag

Purity： 99%

1. Basic Information

• English Name: Methyl Paraben; Methyl 4-hydroxybenzoate
• Chinese Name: 对羟基苯甲酸甲酯；尼泊金甲酯
• CAS Number: 99-76-3
• Molecular Formula: C₈H₈O₃
• Molecular Weight: 152.15 g/mol
• Chemical Structure: Formed by the esterification of the carboxyl group (-COOH) of benzoic acid with methanol, featuring a hydroxyl group (-OH) at the 4-position of the benzene ring. This structure endows it with lipophilicity, enabling penetration of microbial cell membranes to exert antibacterial effects.
• Common Forms: Commercially available products are mostly white crystalline powders or needle-like crystals, odorless or with a slight characteristic smell. A small number are supplied as high-purity granules or 10% ethanol solutions for specialized applications.

2. Physical and Chemical Properties

3. Key Performance Characteristics

1. Broad-Spectrum Antibacterial Activity and Long-Term Preservation
   Methyl Paraben inhibits microbial growth by disrupting intracellular enzyme activity (e.g., dehydrogenase, oxidase) and damaging cell membranes. Its core advantages include:

• Comprehensive Antimicrobial Spectrum: Effective against molds (e.g., Aspergillus niger), yeasts (e.g., Saccharomyces cerevisiae), and both gram-positive/negative bacteria (e.g., Staphylococcus aureus, E. coli). The minimum inhibitory concentration (MIC) ranges from 0.02%–0.1%.
• Synergistic Enhancement: When combined with other parabens (e.g., propyl, butyl paraben), it exhibits a "synergistic effect," reducing the required dosage of individual components. For example, a mixture of 0.05% methyl paraben and 0.02% propyl paraben outperforms 0.1% methyl paraben alone.

1. High Safety and Regulatory Acceptance

• Low Toxicity: Acute oral LD₅₀ (rat) > 5000 mg/kg (classified as "practically non-toxic"); the acceptable daily intake (ADI) is 0–10 mg/kg body weight (FAO/WHO standard), posing minimal health risks under normal usage.
• Metabolic Safety: After ingestion, it is metabolized in the liver to 4-hydroxybenzoic acid, then conjugated with glycine and excreted harmlessly, without bioaccumulation concerns.

1. Strong Compatibility Across Applications

• Formulation-Friendly: Compatible with sugars, flavors, and pigments in food; emulsifiers, humectants, and thickeners in cosmetics; and excipients in pharmaceuticals, without causing precipitation, discoloration, or odor.
• Performance-Neutral: Does not alter the taste of food, the texture of cosmetics, or the efficacy of pharmaceuticals, making it ideal for products with strict sensory and functional requirements.

4. Main Application Fields

1. Food and Beverage Industry (Core Scenario)

2. Cosmetics and Personal Care Products

• Skincare (Lotions, Creams): Added at 0.1%–0.3% to prevent microbial growth in formulations (especially those with natural oils or plant extracts), avoiding product deterioration or separation.
• Color Cosmetics (Foundations, Lipsticks): Added at 0.05%–0.2% to inhibit bacterial and mold growth, ensuring product hygiene without affecting color payoff or texture.
• Oral Care (Toothpaste, Mouthwash): Added at 0.05%–0.15% to suppress oral pathogens (e.g., Streptococcus mutans), aiding in cavity and bad breath prevention.

3. Pharmaceutical and Industrial Fields

• Pharmaceuticals (Oral Liquids, Eye Drops): As a "pharmaceutical excipient" (listed in Chinese Pharmacopoeia CP2025), added at 0.03%–0.1% to prevent microbial contamination during storage, ensuring medication safety.
• Industrial Applications: Added to water-based coatings and adhesives (0.05%–0.2%) to inhibit bacterial and mold proliferation, preventing product odor and performance degradation.

5. Safety and Storage Specifications

1. Safety Warnings (Low-Risk Profile)

While Methyl Paraben is generally safe, precautions include:

• Potential skin sensitivity in a small percentage (<0.1%) of individuals; patch testing is recommended before use.
• Prohibited in infant foods (per China's GB 2760 standard); strict adherence to maximum usage limits is required for other applications.
• Use dust masks during handling to avoid inhalation of fine powders.

2. Regulatory Compliance

• International Standards: Approved by JECFA (Joint FAO/WHO Expert Committee on Food Additives), US FDA (21 CFR §181.23), and EU Regulation EC No 1333/2008, enabling use in over 180 countries.
• Chinese Standards: Complies with National Food Safety Standard for the Use of Food Additives (GB 2760-2024), Cosmetic Safety Technical Specification (2024 Edition), and Chinese Pharmacopoeia (2025 Edition), specifying maximum usage limits (e.g., 0.1% in food, 0.4% in cosmetics).

3. Packaging and Storage

• Packaging Specifications:
  • Food/Pharmaceutical Grade: 25 kg/bag (inner polyethylene film, outer kraft paper composite bag, moisture- and contamination-resistant).
  • Cosmetic Grade: 5 kg/aluminum foil bags (oxidation- and light-proof).
  • Small Batches: 1 kg/hermetically sealed bottles (for laboratory or small-scale trials).
• Storage Conditions:
  • Store in a cool, dry, well-ventilated area at 5–30℃ with relative humidity < 70%. Avoid mixing with strong oxidants, acids, or alkalis.
  • Seal tightly after opening to prevent moisture absorption; caking does not affect activity and can be crushed for normal use.
  • Shelf life of unopened products: 24 months for food grade, 36 months for cosmetic grade.