PARABENS (METHYL, ETHYL, PROPYL, BUTYL)

GENERAL DESCRIPTION

Benzoic acid, the simplest aromatic carboxylic acid containing carboxyl group bonded directly to benzene ring, is a white, crystalline organic compound; melting at 122 C (starting sublime at 100 C);  boiling at 249 C; slightly soluble in water, soluble in ethanol, very slightly soluble in benzene and acetone. Its aqua solution is weakly acidic. It occurs naturally in many plants  and resins. Benzoic acid is also detected in animals. The most of commercial benzoic acid is produced by the reaction of toluene with oxygen at temperatures around 200 C in the liquid phase and in the presence of cobalt and manganese salts as catalysts. It can be prepared also by the oxidation of benzene with concentrated sulphuric acid or carbon dioxide in the presence of catalysts. Other methods are such as by the oxidation of benzyl alcohol, benzaldehyde, cinnamic acid; by hydrolysis of benzonitrile, benzoyl chloride. More than 90% of commercial benzoic acid is converted directly to phenol and caprolactam. Its use in the production of glycol benzoates for the application of plasticizer in adhesive formulations is increasing. It is also used in the manufacture of alkyd resins and drilling mud additive for crude oil recovery applications. It is used as a rubber polymerization activators and retardants. Benzoic acid is converted to its salts and esters for the use of preservative application in foods, drugs and personal products. Sodium benzoate, sodium salt of benzoic acid, is used preferably as one of the principal anti-microbial preservatives used in foods and beverages (but it's concentration is limited usually not exceeding 0.1% because it is poisonous), as it is about 200 times more soluble than benzoic acid. Sodium Benzoate is also used in medications, anti-fermentation additives and tabletting lubricant for pharmaceuticals. The industrial applications are as a corrosion inhibitor, as an additive to automotive engine antifreeze coolants and in other waterborne systems, as a nucleating agents for polyolefin, as a dye intermediate, as a stabilizer in photographic processing and as a catalyst. Wide range of benzoic esters are used as solvents, dying carrier, disinfectant additive, penetrating agent and pesticides and manufacturing other compounds.

Benzoic acid derivatives substituted by hydroxy group or ether containing oxygen atom have active bacteriostatic and  fragrant properties. They are typically used in pharmaceutical and perfumery industry. The destructive metabolic property of oxygen containing benzoic acid derivatives such as protocatechuic acid (3,4-dihydroxybenzoic acid) and veratric acid (3,4-dimethoxybenzoic acid) is used in the application for pharmaceuticals. Protocatechuic acid is a catabolite of epinephrine. Prazosin, a peripheral vasodilator and antihypertensive, is also an example of the applicaion of veratric acid. Hydroxy and ether substituted benzoic acids feature analogue metabolite of aspirin (acetylsalicylic Acid). They are used as intermediates for pharmaceuticals (especially for antipyetic anlgesic, antirheumatism) and other organic synthesis. They are used as matrix for ionization of peptides, proteins and carbohydrates.

Estesrs of hydroxybenzoic acid are recognized as antiseptics. Especially parabens, substituted at 1,4 position, are widely used as preservatives in food and pharmaceuticals.

PRODUCT IDENTIFICATION

METHYL PARABEN

CAS NO. : 99-76-3
FORMULA : C
8H8O3
MOL WT.: 152.15
CHEMICAL NAME : Methyl-4-hydroxybenzoate

METHYL PARABEN

ETHYL PARABEN

CAS NO. : 120-47-8
FORMULA :
C9H10O3
MOL WT.: 166.18
CHEMICAL NAME : Ethyl-4-hydroxybenzoate

ETHYL PARABEN

PROPYL PARABEN

CAS NO. : 94-13-3
FORMULA :
C10H12O3
MOL WT.: 180.20
CHEMICAL NAME :Propyl-4-hydroxybenzoate

PROPYL PARABEN

BUTYL PARABEN

CAS NO. : 94-26-8
FORMULA :
C11H14O3
MOL WT.: 194.23
CHEMICAL NAME : Butyl-4-hydroxybenzoate

BUTYL PARABEN

SPECIFICATION

PROPERTY
METHYL PARABEN

ETHYL PARABEN

PROPYL PARABEN

BUTYL PARABEN

Bibliography

BP USP JP

Appearance

White to Off-white crystalline powder

Assay
99.0 % - 100.5 %
99.0 % - 100.5 %
99.0 % - 100.5 %
99.0 % - 100.5 %
Melting Range
125-128
115-118

95 - 98 ºC.

67.5-72
Acidity
Pass

Pass

Pass

Pass

Sulfate
0.024% max
0.024% max
0.024% max
0.024% max
Loss on Drying
0.5% max
0.5% max
0.5% max
0.5% max
Residue on Ignition
0.10% max
0.10% max
0.10% max
0.10% max
Volatile Impurity
Pass
Pass
Pass
Pass
As
0.001% max
0.001% max
0.001% max
0.001% max

Pb

0.0001% max

0.0001% max

0.0001% max

0.0001% max

SYNONYMS

METHYL PARABEN

Methyl 4-hydroxybenzoate; Methyl Chemosept; Methyl Parasept; 4-Hydroxybenzoic acid methyl ester; Nipagin M; Tegosept M; Aseptoform; Nipagin; 4-Hydroxy methyl benzoate

ETHYL PARABEN

Ethyl 4-hydroxybenzoate; 4-Hydroxybenzoic acid ethyl ester; Nipagin A; Ethyl Parasept; Solbrol A

PROPYL PARABEN

Nipasol; Propyl Chemosept; Solbrol P; Propyl Parasept; Propyl 4-hydroxybenzoate; 4-Hydroxybenzoic acid propyl ester; p-hydroxy propyl benzoate; n-propyl p-hydroxybenzoate; aseptoform p; betacide p; paseptol; propyl aseptoform; protaben p; tegosept p; 4-hydroxybenzoic propyl ester

BUTYL PARABEN

n-Butyl paraben; n-Butyl p-Hydroxybenzoate; Butyl 4-hydroxybenzoate; Butoben; Butyl Chemosept; Butyl Parasept; p-hydroxybenzoic acid n-butyl ester; 4-(butoxycarbonyl)phenol; aseptoform butyl; butyl tegosept; nipabutyl; solbrol b; tegosept butyl; butyl butex; p-Hydroxy butyl benzoate; 4-Hydroxybenzoic acid butyl ester

COMMENTS

A preservative is an additive for foods, pharmaceuticals, personal care products, cosmetics and other industrial products to reduce spoilage that air, fungi, bacteria, or yeast can cause. Members of common preservative for foods, pharmaceuticals, personal care products and cosmetics include:

PRICE INFORMATION