Article · Wikipedia archive · Last revised Jul 27, 2026

Potassium formate

Potassium formate, HCO2K, HCOOK, or KHCO2, is the potassium salt of formic acid. This strongly hygroscopic white solid is an intermediate in the formate potash process for the production of potassium. Potassium formate has also been studied as a potential environmentally friendly deicing salt for use on roads. It has also been suggested for use in a less corrosive liquid desiccant. A 52% solution of potassium formate has a freezing point of −60 °C (−76 °F). Potassium formate brines are sometimes used for heat transfer, despite being much more corrosive than many other liquid coolants, especially to zinc and aluminum but even to many steels, though some formulations are compatible with aluminum and steels.

Last revised
Jul 27, 2026
Read time
≈ 2 min
Length
498 w
Citations
12
Source
Wikipedia ↗
Potassium formate1
source ↗
source ↗
source ↗
Names
Preferred IUPAC name
Potassium formate
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.008.799
UNII
  • InChI=1S/CH2O2.K/c2-1-3;/h1H,(H,2,3);/q;+1/p-1 X markN
    Key: WFIZEGIEIOHZCP-UHFFFAOYSA-M X markN
  • InChI=1/CH2O2.K/c2-1-3;/h1H,(H,2,3);/q;+1/p-1
    Key: WFIZEGIEIOHZCP-REWHXWOFAK
  • C(=O)[O-].[K+]
Properties
CHKO2
Molar mass 84.115 g·mol−1
Appearance Colorless deliquescent crystals
Density 1.908 g/cm3
Melting point 167.5 °C (333.5 °F; 440.6 K)
Boiling point Decomposes
32.8 g/100 mL (0 °C)
331 g/100 mL (25°C)
657 g/100 mL (80 °C)
Solubility soluble in alcohol
insoluble in ether
Basicity (pKb) 10.25
Hazards
GHS labelling:
GHS07: Exclamation mark
Warning
H315, H319, H335
P261, P280, P302+P352, P305+P351+P338
Lethal dose or concentration (LD, LC):
5500 mg/kg (oral, mouse)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
X markN verify (what is checkYX markN ?)

Potassium formate, HCO2K, HCOOK, or KHCO2, is the potassium salt of formic acid. This strongly hygroscopic white solid2 is an intermediate in the formate potash process for the production of potassium.3 Potassium formate has also been studied as a potential environmentally friendly deicing salt for use on roads.45 It has also been suggested for use in a less corrosive liquid desiccant.6 A 52% solution of potassium formate has a freezing point of −60 °C (−76 °F).7 Potassium formate brines are sometimes used for heat transfer, despite being much more corrosive than many other liquid coolants, especially to zinc and aluminum but even to many steels,8 though some formulations are compatible with aluminum and steels.9

Since 1995, potassium formate has been increasingly used in aqueous drilling fluids to increase density, stabilize the hole, and improve drilling performance.101112

References

References

  1. Olsen, J C (editor), Van Nostrand's Chemical Annual, Chapman and Hall, London, 1934
  2. "MSDS - 294454". www.sigmaaldrich.com. Retrieved 2019-03-18.
  3. Concise Encyclopedia Chemistry, Mary Eagleson (1994), page 888. ISBN 978-3-11-011451-5
  4. "Finnish Environment Institute > Main publications on the effect of de-icing chemicals on ground water". www.syke.fi. Retrieved 2015-11-18.
  5. Pasi P. Hellstén; Jani M. Salminen; Kirsten S. Jørgensen & Taina H. Nystén (2005). "Use of potassium formate in road winter deicing can reduce groundwater deterioration". Environ. Sci. Technol. 39 (13): 5095–5100. Bibcode:2005EnST...39.5095H. doi:10.1021/es0482738. PMID 16053115.
  6. "Module 71: Liquid desiccants for dehumidification in building air conditioning systems".
  7. "Potassium Formate for Runway Deicing".
  8. "Brines and antifreeze". Retrieved 2022-01-16.
  9. "Technical information on "TYFOXIT F15-F50: Ready-to-Use, High-Performance Ultra Low Viscous Secondary Refrigerants for Applications Down to –50 °C"" (PDF). Retrieved 2022-01-16.
  10. Hallman, John (August 1, 1996). "Use of formate-based fluids for drilling and completion". Offshore. Endeavor Business Media. Retrieved November 5, 2024.
  11. van Oort, Eric (April 2017). "Shale Stabilization by High-Salinity Formate Drilling Fluids" (PDF). www.aade.org. American Association of Drilling Engineers. Retrieved November 5, 2024.
  12. Kazemihokmabad, Parsa; Khamehchi, Ehsan; Kalatehno, Javad; Ebadi, Reza (June 1, 2024). "A comparative study of brine solutions as completion fluids for oil and gas fields". Scientific Reports. 14. Retrieved November 5, 2024.