Trifluoromethane

Description

Trifluoromethane, CHF3, also known as fluoroform, propellant 23, and refrigerant 23, is a colorless gas that is nonflammable. There are no hazards listed for trifluoromethane. It may be an asphyxiant gas and displace oxygen in the air and in confined spaces. The fourdigit UN identification number is 2035 for the compressed gas and 3136 for the cryogenic liquid. The primary uses for trifluoromethane are as a refrigerant, as a direct coolant for infrared detector cells, and as a blowing agent for urethane foams.

Strictly speaking, fluorocarbon compounds contain only the elements carbon, fluorine, and sometimes hydrogen. However, in industrial applications such as refrigerants and aerosol propellants, the term fluorocarbon has been used to include compounds containing chlorine and bromine atoms, or both. These industrial products have somewhat similar chemical and physical properties. Their relatively inert character and wide range of vapor pressures and boiling points make them especially well suited as refrigerants in a variety of applications, blowing agents for plastic foams, and aerosols.

Chemical properties

Trifluoromethane, also known as Halocarbon-23, is a colorless, nonflammable, and nontoxic gas with a slight ethereal odor at ambient conditions.

The Uses of Trifluoromethane

Refrigerant for low temperetures.

The Uses of Trifluoromethane

The fluorocarbons covered in this monograph are widely used as refrigerants, polymer intermediates, and blowing agents in the manufacture of polymerized foams used in insulation and comfort cushioning. They are also used for making packaging foams, as well as aerosol propellants for products applied in foam or spray form, and fire extinguishing agents. Special mixtures of two or more fluorocarbons, or fluorocarbons and hydrocarbons, are often used to provide desired special properties in particular refrigeration or aerosol propellant applications.
While Tetrafluoromethane is also used as a low-temperature refrigerant gas, it is also widely used by the electronics industry as a dry etchant in microchip manufacture. It is blended with oxygen and used to desmear and etch-back "through holes" on printed circuit boards.

Definition

ChEBI: Fluoroform is a member of fluoromethanes. It has a role as a refrigerant.

General Description

Trifluoromethane is a colorless nonflammable gas. Trifluoromethane is shipped as a liquid under pressure. Trifluoromethane may be narcotic in high concentrations. Under prolonged exposure to fire or heat the containers may rupture violently and rocket. Trifluoromethane is used as a refrigerant.

Reactivity Profile

TRIFLUOROMETHANE, R-23, is chemically inert in many situations, but can react violently with strong reducing agents such as the very active metals and the active metals. They suffer oxidation with strong oxidizing agents and under extremes of temperature.

Hazard

The four-digit UN identification number is 2035 for the compressed gas and 3136 for the cryogenic liquid. The primary uses for trifluoromethane are as a refrigerant, as a direct coolant for infrared detector cells, and as a blowing agent for urethane foams.

Health Hazard

Trifluoromethane is considered an asphyxiant.Vapors may cause dizziness or asphyxiation without warning. Vapors from liquefied gas are initially heavier than air and spread along ground. Contact with gas or liquefied gas may cause burns, severe injury and/or frostbite. Fire may produce irritating, corrosive and/or toxic gases.
At very high concentrations, trifluoromethane may produce cardiac arrhythmias or arrest due to sensitization of the heart to adrenaline and noradrenalin. Exposure to fluorocarbon thermal decomposition products may produce flu-like symptoms including chills, fever, weakness, muscular aches, headache, chest discomfort, sore throat, and dry cough. Complete recovery usually occurs within 24 hours after exposure.

Fire Hazard

Some may burn but none ignite readily. Containers may explode when heated. Ruptured cylinders may rocket.

Materials Uses

The fluorocarbons are generally compatible with most of the common metals except at high temperatures. At elevated temperatures, the following metals resist fluorocarbon corrosion (and are named in decreasing order of their corrosive resistance): Inconel, stainless steel, nickel, steel, and bronze. Water or water vapor in fluorocarbon systems will corrode magnesium alloys or aluminum containing over 2 percent magnesium. These metals are not recommended for use with fluorocarbon systems in which water may be present.

Safety Profile

Narcotic in high concentration. A mild respiratory irritant. Mutation data reported. See also FLUORIDES. When heated to decomposition it emits toxic fumes of F-.

Physiological effects

The fluorocarbons used in industry generally have low levels of toxicity, and hazards related to their use are minimal. These compounds have been extensively studied by many investigators under a variety of conditions.

storage

Use forced ventilation and local exhaust, or both, to prevent an accumulation of gas that could reduce the oxygen level to below 19.5%. Ensure good floor ventilation. Use a check valve or trap in the discharge line to prevent back flow into the cylinder. Where applicable, use a pressure-reducing regulator when connecting a cylinder to a low-pressure piping system. For flammable fluorocarbons, adherence to pertinent electrical standards is necessary. Personnel should not weld, solder, braze, or have an open flame of any type in atmospheres containing flammable or nonflammable fluorocarbons.

GRADES AVAILABLE

Fluorocarbons are available for commercial and industrial use in various grades with essentially the same composition from one producer to another. Purities of most fluorocarbon products are a minimum of 99 volume percent. For special applications very high purity grades are available.