Pentafluoroethane

Pentafluoroethane is a refrigerant with the formula CF₃CHF₂. Although it has zero ozone depletion potential, it has high global warming potential, reported by the United States Environmental Protection Agency (EPA) as 3450 times that of carbon dioxide.

Pentafluoroethane in an 'near'zeotropic mixture with difluoromethane is known as R-410a, a common replacement for various chlorofluorocarbons (commonly known as Freon) in new refrigerant systems. Pentafluoroethane is also used as a fire suppression agent in fire suppression systems.

Fire Suppression Systems

HFC-125 (ECARO-25 / FE-25 / NAF S 125) is a gaseous fire suppression agent which can be used in clean agent fire suppression systems. It is generally used in situations where water from a fire sprinkler would damage expensive equipment, or where water-based fire protection is impractical, such as museums, banks, clean rooms and hospitals. HFC-125 does not deplete ozone (ODP 0). The HFC-125 clean agent is stored in a pressurized container and introduced into the hazard as a gas. The agent is odorless, colorless, electrically non-conductive, non-corrosive, and leaves no residue. It is used in occupied enclosed areas that contain high-value assets.

1,1,1,2,3,3,3-Heptafluoropropane

1,1,1,2,3,3,3-Heptafluoropropane, also called heptafluoropropane, HFC-227 or HFC-227ea (ISO name), as well as apaflurane (INN), is a colourless, odourless gaseous halocarbon commonly used as a gaseous fire suppression agent.

Chemistry

Its chemical formula is CF₃-CHF-CF₃, or C₃HF₇. With a boiling point of -16.4 °C, it is a gas at room temperature. It is slightly soluble in water (260 mg/L).

Use

HFC-227ea finds use in fire suppression systems in data processing and telecommunication facilities, and in protection of many flammable liquids and gases. HFC-227ea falls in the category of Clean Agents and is governed by NFPA 2001 - Standard for Clean Agent Fire Extinguishing Systems. Effective fire suppression requires introducing a concentration of the HFC-227ea agent between 6.25% and 9% depending on the hazard being protected. Its NOAEL level for cardiac sensitization is 9%. The United States Environmental Protection Agency allows concentration of 9% volume in occupied spaces without mandated egress time, or up to 10.5% for a limited time. Most fire suppression systems are designed to provide concentration of 6.25-9%.

Fluoroform

Fluoroform is the chemical compound with the formula CHF₃. It is one of the "haloforms", a class of compounds with the formula CHX₃ (X = halogen). Fluoroform is used in diverse niche applications and is produced as a by-product of the manufacture of Teflon. It is also generated biologically in small amounts apparently by decarboxylation of trifluoroacetic acid.

Synthesis

Fluoroform was first obtained by Maurice Meslans in the violent reaction of iodoform with dry silver fluoride in 1894. The reaction was improved by Otto Ruff by substitution of silver fluoride by a mixture of mercury fluoride and calcium fluoride. The exchange reaction works with iodoform and bromoform, and the exchange of the first two halogen atoms by fluorine is vigorous. By changing to a two step process, first forming a bromodifluoro methane in the reaction of antimony trifluoride with bromoform and finishing the reaction with mercury fluoride the first efficient synthesis method was found by Henne.

Industrial applications