Propyl gallate
[CAS# 121-79-9]

Identification

• Classification: Food additive >> Antioxidants
• Name: Propyl gallate
• Synonyms: Propyl 3,4,5-trihydroxybenzoate; 3,4,5-Trihydroxybenzoic acid propyl ester
• Molecular Formula: C₁₀H₁₂O₅
• Molecular Weight: 212.20
• CAS Registry Number: 121-79-9
• EC Number: 204-498-2
• FEMA: 2947
• SMILES: CCCOC(=O)C1=CC(=C(C(=C1)O)O)O

Properties

• Melting point: 146-150 °C
• Water solubility: 0.35 g/100 mL (25 °C)
• Flash point: 187 °C

Safety Data

• Hazard Symbols: GHS05;GHS07;GHS09 Danger
• Risk Statements: H302-H317-H318-H410
• Safety Statements: P261-P264-P270-P272-P273-P280-P301+P312+P330-P302+P352-P305+P351+P338+P310-P333+P313-P391-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Acute toxicity	Acute Tox.	4	H302
Skin sensitization	Skin Sens.	1	H317
Chronic hazardous to the aquatic environment	Aquatic Chronic	1	H410
Acute hazardous to the aquatic environment	Aquatic Acute	1	H400
Serious eye damage	Eye Dam.	1	H318
Skin sensitization	Skin Sens.	1B	H317

Discovery and Applications

Propyl gallate, a member of the gallate family of esters, is an important chemical compound used primarily as an antioxidant. Its discovery and application have made it a valuable component in various industries, particularly in food preservation and cosmetics.

Propyl gallate was first synthesized in the early 20th century. It is the propyl ester of gallic acid, a naturally occurring phenolic acid found in various plants. The synthesis of propyl gallate involves the esterification of gallic acid with propanol. This reaction produces a compound that exhibits significant antioxidant properties, making it useful in a range of applications.

One of the primary uses of propyl gallate is in the food industry. It is employed as an antioxidant to prevent the oxidation of fats and oils in food products. By inhibiting the oxidative degradation of these components, propyl gallate helps to extend the shelf life of processed foods and maintain their quality. This application is particularly valuable in products containing high levels of fats, such as snack foods, margarine, and baked goods.

In addition to its use in food preservation, propyl gallate is utilized in the cosmetic and pharmaceutical industries. It acts as an antioxidant in cosmetic formulations, helping to stabilize products and prevent the deterioration of active ingredients. This property is beneficial in extending the shelf life of cosmetics and personal care products, ensuring their effectiveness and safety over time.

Propyl gallate also finds application in the production of polymers and resins. Its antioxidant properties are advantageous in stabilizing these materials, preventing premature degradation caused by oxidation. This application is important in industries where durable and long-lasting materials are required.

The safety and efficacy of propyl gallate have been the subject of various studies. Regulatory agencies such as the Food and Drug Administration (FDA) and the European Food Safety Authority (EFSA) have reviewed its safety profile, and it is generally considered safe for use in food and cosmetic products within established limits. However, its use is subject to regulatory guidelines to ensure that it does not exceed acceptable levels in consumer products.

In summary, propyl gallate is a versatile chemical compound with important applications in food preservation, cosmetics, and polymer production. Its antioxidant properties play a crucial role in maintaining the quality and stability of various products, making it a valuable ingredient in multiple industries.

References

1979. Cytogenetic activity of some common antioxidants and their interaction with x-rays. Mutation Research/Genetic Toxicology.
DOI: 10.1016/0165-1218(79)90018-1

2007. Investigating the Location of Propyl Gallate at Surfaces and Its Chemical Microenvironment by 1H NMR. Lipids.
DOI: 10.1007/s11745-007-3053-5

2024. Mitigating Toxic Compounds in Deep-Fried Meat: The Antioxidant Potential of Edible Coatings. Food and Bioprocess Technology.
DOI: 10.1007/s11947-024-03606-7