CAS 64-18-6 · Strongest Simple Carboxylic Acid
Formic Acid
Methanoic Acid · HCOOH · MW 46.03 g/mol
The simplest carboxylic acid and the strongest of the common organic acids. Formic acid's combination of high acidity, complete water miscibility, and reducing properties makes it indispensable in leather tanning, textile processing, rubber production, and agriculture. Texas-Chem supplies formic acid in 85%, 90%, 94%, and anhydrous grades.
Formula
HCOOH
Boiling Point
100.8 °C
pKa
3.74
Grades
85% · 90% · 94% · 99%
Structural Formula
Simplest carboxylic acid — hydrogen atom directly bonded to the carboxyl group
Safety & Regulatory
- NFPA Health
- 3 — Serious hazard
- NFPA Flammability
- 2 — Moderate hazard
- NFPA Reactivity
- 0 — Stable
- OSHA PEL (TWA)
- 5 ppm (9 mg/m³)
- ACGIH TLV-TWA
- 5 ppm
- ACGIH TLV-STEL
- 10 ppm
- DOT Hazard Class
- 8 — Corrosive
- UN Number
- UN 1779
Corrosive and flammable — use acid-resistant PPE and adequate ventilation. SDS available upon request.
Grades & Packaging
Available Grades
Pack Sizes
Physical & Chemical Properties
| Molecular Formula | HCOOH |
| Molecular Weight | 46.03 g/mol |
| CAS Number | 64-18-6 |
| Boiling Point | 100.8 °C (213.4 °F) |
| Melting Point | 8.4 °C (47.1 °F) |
| Flash Point | 50 °C (122 °F) — Flammable |
| Density | 1.220 g/cm³ at 20 °C |
| Vapor Pressure | 4.5 kPa at 20 °C |
| Solubility in Water | Miscible in all proportions |
| pKa | 3.74 at 25 °C |
| Refractive Index | 1.3714 at 20 °C |
| Auto-ignition Temp. | 434 °C (813 °F) |
Industrial Applications
Leather Tanning
Primary acidulant in chrome tanning processes — formic acid adjusts bath pH and promotes uniform chromium uptake into hides. Its strong acidity and complete water miscibility make it ideal for leather processing.
Textile Dyeing & Finishing
pH regulator in acid dye baths for wool, nylon, and silk. Formic acid provides precise pH control (2.5–4.5) for optimal dye uptake and levelness without damaging fibers.
Silage Preservation
Preservative in animal feed silage — formic acid inhibits bacterial and fungal growth, reduces dry matter losses, and improves nutritional value of stored forage. Widely used in European agriculture.
Rubber Coagulation
Coagulant for natural rubber latex — formic acid precipitates rubber from latex in a controlled, uniform manner. Produces higher-quality rubber than sulfuric acid coagulation.
Chemical Synthesis
Reducing agent and formylating agent in organic synthesis. Used to produce formate esters, formamides, and as a hydrogen source in transfer hydrogenation reactions.
Cleaning & Descaling
Effective descaler for removing calcium and iron deposits from heat exchangers, boilers, and industrial equipment. Stronger than acetic acid but safer to handle than hydrochloric acid for many applications.
Why Source Formic Acid from Texas-Chem?
- 35+ years supplying industrial acids to Texas manufacturers
- Multiple concentration grades — 85%, 90%, 94%, and anhydrous
- Drums and totes with proper corrosive-rated packaging
- Competitive pricing backed by top-tier producer relationships
- Technical support and SDS documentation with every order
- Same-day quotes for standard quantities