4-Hydroxybenzoic acid, methyl ester
Synonyms
Methyl p-hydroxybenzoate;
Methyl 4-hydroxybenzoate;
Benzoic acid, 4-hydroxy-, methyl ester;
Methyl parahydroxybenzoate;
Methylparaben;
Category
Non-ionic surfactant
> Phenol
>> Ester-group Phenol
Chemical Numbering System
CAS: 99-76-3
EINECS: 202-785-7
Molecular Formula & Molecular Weight
Molecular Formula: C8H8O3
Molecular Weight: 152.15
Structure
Properties
Appearance (1), white crystal powder.
Solubility soluble in water.
Physical - chemical properties
|
Water solubility, g/L |
2.5 (25°C)[1] |
Stability stable. Under strong acid or strong alkali condition, easily hydrolyzed.
Risk Solid form: flammable material; irritation, irritation to skin, eye, respiratory system. Harmful products of combustion are CO, CO2 and so on. Contact with strong oxidants, can cause to burn.
GHS label: 
Animal Toxicity
Table 1 Animal toxicity values
|
rat subcutaneous LD50 |
> 500mg/kg[2] |
|
rabbit oral LD50 |
6000mg/kg[2] |
|
guinea pig oral LD50 |
3000mg/kg[2] |
|
mouse oral LD50 |
> 8000mg/kg[2] |
|
mouse subcutaneous LD50 |
1200mg/kg[2] |
|
mouse intraperitoneal LD50 |
960mg/kg[2] |
Ecology may be hazardous to environment. Water body should be given special attention.
Biodegradability biodegradable.
Characteristics excellent antimicrobial, antibacterial, preservative abilities. It is often used in combination with other nipagin esters. Among homologues, weakest antimicrobial capacity. Can potentiate UV-induced damage of skin.
Synthesis
Quality Standards & Test Methods
1, Physical and chemical indexes
|
Item |
Physical and chemical indexes |
|
Solid |
|
|
Actives, %, ≥ |
95.0 |
Test Methods
(1), Actives
GB/T 13173 Surface active agents -- Detergents -- Testing methods
2, Hazardous substances indexes
|
Item |
Hazardous substances indexes |
|
Solid |
|
|
Heavy metals (as Pb), mg/kg, ≤ |
20 |
|
As, mg/kg, ≤ |
3 |
Test Methods
(1), Heavy metals (as Pb)
Safety and Technical Standards for Cosmetics (2015 Edition)
GB/T 30799 The test method of food detergents -- Determination of heavy metals
(2), As
Safety and Technical Standards for Cosmetics (2015 Edition)
GB/T 30797 The test method of food detergents -- Determination of total arsenic
3, Product standards
(1), Chinese standards
(1a), Chinese Pharmacopoeia (2015 Edition) Methylparaben
4, Further explanation
(a), On physical and chemical indexes: firstly, shall be indicated carbon atom distribution; secondly, shall be indicated average molecular weight.
(b), Used in cosmetics, should be test for harmful substances or furtherly test for microorganisms, according to local regulations and standards.
Major Uses
1, Typical applications
Use as antimicrobial agent, preservative.
2, Personal care products
Preservative in personal care products.
Further information:
(1), In accordance with Safety and Technical Standards for Cosmetics (2015 Edition) of China, be included in the allowed preservatives.
Maximum concentration:
0.4% (as acid) for single ester;
0.8% (as acid) for mixtures of esters, and the sum of the individual concentrations of butyl and propylparaben and their salts does not exceed 0.14%.
(2), In accordance with EU regulations (EC) No 1004/2014, be included in Annex V/12.
Maximum concentration:
0.4% (as acid) for single ester;
0.8% (as acid) for mixtures of esters, and the sum of the individual concentrations of butyl and propylparaben and their salts does not exceed 0.14%.
3, Medicine
Pharmaceutical excipient, use as bacteriostat. (This section is for reference only, should be implemented according to local Pharmacopoeia.)
Manufacturers
References
[1]: HSDB. 99-76-3, Methylparaben
[2]: ChemIDplus. 99-76-3, Methylparaben
Update: 20140929(1); 20190908(2)