Acetic Acid vs. Formic Acid

What's the Difference?

Acetic acid and formic acid are both organic acids commonly found in nature. They have similar chemical structures, with acetic acid having two carbon atoms and formic acid having one carbon atom. However, they differ in their physical properties and uses. Acetic acid, also known as vinegar, has a pungent smell and is commonly used in cooking, food preservation, and as a cleaning agent. On the other hand, formic acid has a strong, irritating odor and is primarily used in industries such as agriculture, textile, and leather as a preservative, disinfectant, and dyeing agent. Additionally, formic acid is known for its use in the production of rubber, plastics, and pharmaceuticals.


AttributeAcetic AcidFormic Acid
Chemical FormulaCH3COOHHCOOH
Molecular Weight60.052 g/mol46.025 g/mol
Common NameVinegarFormic Acid
OdorPungent, vinegar-likePungent, strong, irritating
Boiling Point118.1 °C100.8 °C
Solubility in WaterFully miscibleFully miscible
AcidityWeak acidStrong acid
UsesFood preservative, cleaning agent, solventPreservative, pesticide, leather tanning

Further Detail


Acetic acid and formic acid are both organic acids commonly found in nature. They have distinct chemical properties and applications, making them important compounds in various industries. In this article, we will explore the attributes of acetic acid and formic acid, including their chemical structures, physical properties, uses, and potential health effects.

Chemical Structures

Acetic acid, also known as ethanoic acid, has the chemical formula CH3COOH. It consists of two carbon atoms, four hydrogen atoms, and two oxygen atoms. The carbon atoms are bonded to each other, with one carbon atom bonded to three hydrogen atoms and the other carbon atom bonded to an oxygen atom and a hydroxyl group (-OH). The hydroxyl group gives acetic acid its acidic properties.

Formic acid, on the other hand, has the chemical formula HCOOH. It contains one carbon atom, two hydrogen atoms, and two oxygen atoms. The carbon atom is bonded to two oxygen atoms, one through a double bond and the other through a single bond. The hydrogen atom is bonded to the carbon atom, and the hydroxyl group is attached to the same carbon atom. The presence of the hydroxyl group makes formic acid an acid as well.

Physical Properties

Acetic acid is a colorless liquid with a pungent odor. It has a boiling point of approximately 118 degrees Celsius and a melting point of around 16 degrees Celsius. Acetic acid is miscible with water, meaning it can mix with water in all proportions. It is also flammable and can form explosive mixtures with air when its concentration is high enough.

Formic acid, on the other hand, is a colorless liquid with a strong, pungent odor similar to that of acetic acid. It has a lower boiling point of about 100 degrees Celsius and a melting point of around 8 degrees Celsius. Like acetic acid, formic acid is also miscible with water and flammable. However, it has a higher vapor pressure than acetic acid, making it more volatile.


Acetic acid has a wide range of applications in various industries. One of its most well-known uses is as a key component in vinegar, which is commonly used in cooking and food preservation. Acetic acid is also used in the production of various chemicals, including vinyl acetate monomer (VAM), which is used in the manufacturing of adhesives, coatings, and textiles. Additionally, it is utilized in the production of solvents, dyes, and pharmaceuticals.

Formic acid also finds applications in different industries. It is commonly used as a preservative and antibacterial agent in livestock feed and silage. Formic acid is utilized in the leather industry for tanning and dyeing processes. It is also employed as a coagulant in the rubber industry and as a reducing agent in various chemical reactions. Furthermore, formic acid is used in the production of formate salts, which have applications in electroplating, oil drilling, and textile dyeing.

Health Effects

Acetic acid is generally recognized as safe for consumption in small amounts, such as in vinegar. However, exposure to concentrated acetic acid can cause irritation to the skin, eyes, and respiratory system. Ingesting large quantities of acetic acid can be harmful and may lead to corrosive damage to the gastrointestinal tract. It is important to handle acetic acid with care and follow safety guidelines when using it in industrial settings.

Formic acid, when inhaled or exposed to the skin, can cause irritation and burns. It is considered to be more toxic than acetic acid. Inhalation of high concentrations of formic acid vapor can lead to severe respiratory distress and damage to the respiratory system. Ingesting formic acid can cause severe burns to the mouth, throat, and gastrointestinal tract. It is crucial to handle formic acid with caution and use appropriate protective measures to prevent exposure.


Acetic acid and formic acid are two organic acids with distinct chemical structures, physical properties, and applications. Acetic acid is commonly used in the food industry, chemical production, and pharmaceuticals, while formic acid finds applications in livestock feed, leather tanning, and various chemical processes. Both acids have potential health effects and should be handled with care. Understanding the attributes of acetic acid and formic acid is essential for their safe and effective use in different industries.

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