What is formic acid
Formic acid is the simplest organic acid with the chemical formula HCOOH and CAS number 64-18-6. This material was first found in ant secretions, which is why it is also called “ant acid.” It is a clear, colorless liquid with a strong, sharp smell. It freezes around 8°C and boils at about 101°C, and it mixes easily with water, alcohol, and other liquids.
The structure of formic acid is unique—it shows both the properties of an organic acid and the reducing ability similar to formaldehyde. It is much stronger than common acetic acid (vinegar), about 10 times more acidic. It can also react with silver-mirror solutions and be oxidized by strong oxidizers like potassium permanganate into carbon dioxide and water. When heated with concentrated sulfuric acid to 60–80°C, it breaks down into carbon monoxide and water.
Main Types and Grades of Formic Acid
Depending on how it is made and what it is used for, formic acid is mainly divided into the following types:
Industrial Grade Formic Acid
This is the most common type, available in concentrations such as 85%, 90%, 94%, and 99%. The 85% grade is widely used in leather processing, textile dyeing, and as a preservative in animal feed. The 94% grade, with higher purity, is often used in making pharmaceutical intermediates and in rubber processing. The 99% high-purity formic acid serves as a special solvent or reducing agent in electronic cleaning and fine chemical production.
Food Grade Formic Acid
Food grade formic acid (food additive E236) must meet strict safety standards with very low heavy metal content. It is mainly used as a food preservative and feed additive. In the EU, it is allowed in pickles and fruit juices at levels usually below 0.15%. Specialized suppliers produce food-grade formic acid through advanced purification, resulting in high purity and low water content.
Bio-Based Formic Acid
This is an eco-friendly type produced recently, made from biomass fermentation or from carbon dioxide and hydrogen. It is greener than traditional chemical synthesis. Several large international companies now produce it on a large scale, mainly for hydrogen storage and transport in the energy sector. It stays liquid at low temperatures and has promising applications.
Industrial Uses of Formic Acid
Because it is both acidic and a reducing agent, formic acid is important in many industries:
Leather and Textile Industry
In leather processing, formic acid is essential for de-ashing and tanning. Before chrome tanning, adding a small amount (about 1–2% of the leather’s weight) helps adjust pH, allowing chromium salts to penetrate better. This reduces chromium use and makes the leather softer and fuller. Globally, about 35% of formic acid is used in tanning.
In textile dyeing, it acts as an aid for acid dyes, improving color fastness on wool and reducing wastewater pollution. In nylon carpet printing, adjusting the pH to 4.5–5.0 with formic acid solution gives sharper patterns and longer-lasting colors.
Agriculture and Feed Industry
In feed production, adding formic acid (about 0.8–1.2%) to silage quickly lowers pH, stops harmful bacteria and yeast from growing, reduces feed loss, and can help cut methane emissions from cows. Studies show that adding calcium formate (the calcium salt of formic acid) to piglet feed improves growth and reduces diarrhea.
In beekeeping, formic acid is an effective treatment against Varroa mites. Applying a 65% solution into beehives can kill over 95% of mites within 24 hours, with little harm to bee larvae. This method is now used by most beekeepers worldwide.
Chemical and New Energy Sectors
Formic acid is a key raw material in chemical production. In China, over half of it is used to make pharmaceuticals, such as caffeine and vitamin B1. It is also important in producing certain pesticides.
In new energy applications, formic acid is seen as a “liquid hydrogen carrier.” Hydrogen and carbon dioxide can be combined into formic acid for storage and transport, and then broken down to release hydrogen for fuel cells. Some countries already have formic acid hydrogen refueling stations, with refueling times similar to traditional gas stations.
How to Use Formic Acid Safely
Operating Guidelines and Dosage Control
When using formic acid, concentration and amount must be controlled based on the application. In leather de-ashing, high-concentration formic acid is usually diluted to 10–15% and sprayed evenly while stirring the leather to avoid local over-acidification that can make leather brittle. In textile dyeing, it is added in several steps after the dye bath reaches 60°C, with about 15 minutes between additions. Total usage is typically 1–3% of the fabric weight.
In chemical synthesis, formic acid is often used as a reducing agent or solvent. For example, to make chromium formate, a 20% formic acid solution is slowly added to chromic acid solution while keeping the temperature below 50°C. After adding, stirring continues for about 2 hours to obtain high-purity chromium formate crystals.
Safety Measures
Formic acid is highly corrosive and irritating. Skin contact can cause chemical burns, and its vapor can harm eyes and the respiratory tract. Always wear acid-resistant gloves (nitrile is recommended), safety goggles, and a respirator. Work areas must be well-ventilated to avoid high vapor concentrations.
Store formic acid in plastic or fiberglass containers. Keep it away from oxidizers (potassium nitrate) and strong bases (sodium hydroxide). Storage areas should have ventilation and flammable gas detectors. For small spills, cover with sand or absorbent material and neutralize with soda ash solution. Large spills require professional cleanup.
Emergency Response
Skin contact: Remove contaminated clothing immediately and rinse with plenty of water for at least 15 minutes. If blisters or sores appear, apply baking soda ointment and seek medical help.
Eye contact: Hold eyelids open and rinse with saline or clean water for 10 minutes. Then use vitamin C eye drops.
Inhalation: Move to fresh air immediately. Keep the airway clear and give oxygen if needed. Seek medical attention if coughing or chest tightness occurs.
Ingestion: Drink 100–200 mL of milk or egg white. Do not induce vomiting. Go to the hospital as soon as possible.
Purchasing Tips and Choosing a Supplier
Key Points for Buyers
When selecting a formic acid supplier, focus on product purity (check impurities and water content for industrial grade, heavy metals for food grade), production process, supply chain reliability, and technical support. Consider signing long-term agreements and request third-party test reports to ensure quality.
Why Choose Sinoright
Sinoright is a professional supplier of chemical products, offering a range of formic acid products. Located in Dalian, we (Sinoright) respond quickly to global needs of formic acid. Our industrial grade formic acid is made from quality materials, has stable purity, is certified, and comes in various packaging options.
For food additive customers, Sinoright provides food grade formic acid that meets international standards, with very low heavy metal content. Multiple packaging sizes and payment methods (T/T, L/C, D/P, D/A, O/A, Ali Pay) are available. The company also offers customized solutions and has supplied many large enterprises reliably.