Fluoroform

HFC-23 mm

Halogenated gas concentrations 1978-present

Fluoroform is a chemical compound with the formula CHF₃. It is a colorless, non-flammable gas under room temperature and is significantly colder than the air. Fluoroform is part of a group of compounds known as halomethanes, which are derivatives of methane where one or more hydrogen atoms have been replaced by halogen atoms. Fluoroform is specifically a fluorocarbon, with three fluorine atoms replacing three of the four hydrogen atoms in methane.

Properties

Fluoroform has several notable physical and chemical properties. It has a boiling point of -82.1 °C and a melting point of -155.15 °C, making it a gas at room temperature and pressure. Its high electronegativity due to the presence of fluorine atoms makes it relatively inert, although it can act as a weak Lewis acid. Fluoroform is slightly soluble in water but more soluble in organic solvents.

Production

Fluoroform is produced both as a byproduct in the manufacturing of Teflon (polytetrafluoroethylene) and through the intentional fluorination of methane or chloroform. The latter method involves the reaction of hydrogen fluoride with chloroform in the presence of a catalyst.

Uses

Historically, fluoroform was used as a refrigerant and as a fire extinguishing agent due to its non-flammable nature. However, its use has declined due to environmental concerns, particularly its high global warming potential (GWP). Fluoroform is a potent greenhouse gas, with a GWP over 11,000 times that of carbon dioxide over a 100-year period. Today, its applications are more specialized, including its use in the semiconductor industry for plasma etching in the production of microelectronics.

Environmental Impact

The environmental impact of fluoroform is significant due to its potent greenhouse gas effect. Its release into the atmosphere contributes to global warming. Consequently, there are international efforts to reduce emissions of fluoroform and other high-GWP gases through regulations and the development of alternative substances with lower environmental impacts.

Safety

Fluoroform is generally considered to have low toxicity, but it can cause asphyxiation in high concentrations by displacing air. Handling of fluoroform requires appropriate safety measures to prevent inhalation and direct contact.