Butyric acid
[CAS 107-92-6]

Identification

• Classification: Organic raw materials >> Carboxylic compounds and derivatives >> Acyclic carboxylic acid
• Name: Butyric acid
• Synonyms: n-Butyric acid
• Molecular Formula: C₄H₈O₂
• Molecular Weight: 88.11
• CAS Registry Number: 107-92-6
• EC Number: 203-532-3
• FEMA: 2221
• SMILES: CCCC(=O)O

Properties

• Density: 0.958
• Melting point: -7.9 °C
• Boiling point: 162-165 °C
• Refractive index: 1.3965-1.3995
• Flash point: 69 °C
• Water solubility: MISCIBLE

Safety Data

• Hazard Symbols: GHS05;GHS07 Danger
• Risk Statements: H314
• Safety Statements: P260-P264-P264+P265-P270-P280-P301+P317-P301+P330+P331-P302+P361+P354-P304+P340-P305+P354+P338-P316-P317-P321-P330-P363-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin corrosion	Skin Corr.	1B	H314
Acute toxicity	Acute Tox.	4	H302
Serious eye damage	Eye Dam.	1	H318
Specific target organ toxicity - single exposure	STOT SE	3	H335
Skin sensitization	Skin Sens.	1B	H317
Acute toxicity	Acute Tox.	3	H311
Eye irritation	Eye Irrit.	2	H319
Skin corrosion	Skin Corr.	1A	H314

• Transport Information: UN 2820

Discovery and Applications

Butyric acid, also known as butanoic acid, is a carboxylic acid with the molecular formula C₄H₈O₂. First isolated from rancid butter in 1814 by the French chemist Michel Eugène Chevreul, butyric acid is responsible for the distinctive odor of spoiled butter and other fermented products. Its name is derived from the Greek word “butyrum,” meaning butter, as it is one of the primary fatty acids found in dairy products. Over time, the chemical’s unique properties, including its relatively simple structure and reactivity, led to its use in numerous fields, ranging from food and fragrance to agriculture and pharmaceuticals.

Butyric acid is a short-chain fatty acid that is both water- and fat-soluble, allowing it to play a role in various biological and industrial processes. In its structure, the molecule consists of a four-carbon chain with a terminal carboxyl group, which provides its acidic characteristics. Butyric acid can be synthesized through chemical processes, but it is most commonly produced by anaerobic fermentation, where bacteria break down carbohydrates, yielding butyric acid as a byproduct. This microbial production pathway is also how butyric acid is generated in the human digestive system, where it supports gut health and energy metabolism in colon cells.

In the food industry, butyric acid is used as a flavoring agent, adding a buttery or tangy taste to processed foods and enhancing the aroma of dairy-based products. It also has preservative properties, and in some cases, it is used to inhibit microbial growth in packaged foods. Butyric acid is a precursor to several esters used in flavor and fragrance industries, where it contributes fruity or floral notes to perfumes and cosmetics.

In agriculture, butyric acid derivatives are used as feed additives in livestock, primarily for their benefits to gut health. Butyric acid has been shown to support digestion and nutrient absorption in animals, leading to improved growth and feed efficiency. In the pharmaceutical sector, butyric acid is being studied for its potential anti-inflammatory and anticancer effects, particularly in the context of colon health, where it helps regulate cellular growth and immune responses.

The discovery and continued research into butyric acid have highlighted its value across different industries. From its role as a natural component in digestion to its applications in food, agriculture, and medicine, butyric acid exemplifies the versatility of naturally occurring compounds in enhancing health, industrial processes, and product development.

References

1990. Regulation of thyroid hormone receptor and c‐erbA mRNA levels by butyrate in neuroblastoma (N2A) and glioma (C6) cells. Journal of Neuroscience Research.
DOI: 10.1002/jnr.490270102

1991. Rectal irrigation with short-chain fatty acids for distal ulcerative colitis. Preliminary report. Digestive Diseases and Sciences.
DOI: 10.1007/bf01300754

2024. Increasing the quality and complexity of pulped coffee fermentation with Lactiplantibacillus plantarum and selected yeasts. European Food Research and Technology.
DOI: 10.1007/s00217-024-04640-7