Name: Chlorodifluoroethane (HCFC)
CAS No: 1-Chloro-1, 1-difluoroethane [75-68-3]
None Adopted
1,1-Difluoro-1-chloroethane; Dymel 142b; Genetron 142b; HCFC 142b; P-142b; propellant 142b; refrigerant 142b; Solkane 142b.
1-Chloro-1, 1-difluoroethane [75-68-3]
C2H3ClF2 100.50
Chlorodifluoroethane is a hydrochlorofluorocarbon (HCFC) aerosol propellant previously used in topical pharmaceutical formtions. However, it is no longer permitted for use in pharmaceutical formulations because of its harmful effects on the environment. It was also generally used in conjunction with difluoroethane to form a propellant blend with a specific gravity of 1. Chlorodifluoroethane was also used in combination with chlorodifluoromethane and hydrocarbon propellants. Chlorodifluoroethane may be used as a vehicle for dispersions and emulsions.
Chlorodifluoroethane is a liquefied gas and exists as a liquid at room temperature when contained under its own vapor pressure, or as a gas when exposed to room temperature and atmospheric pressure. The liquid is practically odorless and colorless. Chlorodifluoroethane is noncorrosive and nonirritating
Autoignition temperature 6328C Boiling point 9.88C Critical temperature 137.18C Density 1.11 g/cm3 for liquid at 258C; 1.03 g/cm3 for liquid at 54.58C. Flammability Flammable. Limits of flammability 6.2–17.9% v/v in air. Melting point 1318C Solubility Soluble 1 in 715 parts of water at 208C. Vapor density (absolute) 4.487 g/m3 at standard temperature and pressure. Vapor density (relative) 3.48 (air = 1) Vapor pressure 339 kPa (49.2 psia) at 258C (29.1 psig at 21.18C); 772 kPa (112.0 psia) at 54.58C. Viscosity (dynamic) 0.33 mPa s (0.33 cP) for liquid at 218C.
Chlorodifluoroethane is a nonreactive and stable material. The liquefied gas is stable when used as a propellant and should be stored in a metal cylinder in a cool, dry place
Compatible with the usual ingredients used in the formulation of pharmaceutical aerosols. Chlorodifluoroethane can react vigorously with oxidizing material
Chlorodifluoroethane is prepared by the chlorination of difluoroethane in the presence of a suitable catalyst; hydrochloric acid is also formed. The chlorodifluoroethane is purified to remove all traces of water and hydrochloric acid, as well as traces of the starting and intermediate materials
Chlorodifluoroethane is no longer permitted for use as an aerosol propellant in topical pharmaceutical formulations. It is generally regarded as an essentially nontoxic and nonirritant material. Deliberate inhalation of excessive quantities of chlorofluorocarbon propellant may result in death, and the following ‘warning’ statements must appear on the label of all aerosols: WARNING: Avoid inhalation. Keep away from eyes or other mucous membranes. (Aerosols designed specifically for oral and nasal inhalation need not contain this statement.) WARNING: Do not inhale directly; deliberate inhalation of contents can cause death. or WARNING: Use only as directed; intentional misuse by deliberately concentrating and inhaling the contents can be harmful or fatal. Additionally, the label should contain the following information: WARNING: Contents under pressure. Do not puncture or incinerate container. Do not expose to heat or store at room temperature above 1208F (498C). Keep out of the reach of children. In the USA, the Environmental Protection Agency (EPA) additionally requires the following information on all aerosols containing chlorofluorocarbons as the propellant: WARNING: Contains a chlorofluorocarbon that may harm the public health and environment by reducing ozone in the upper atmosphere.
Chlorodifluoroethane is usually encountered as a liquefied gas and appropriate precautions for handling such materials should be taken. Eye protection, gloves, and protective clothing are recommended. Chlorodifluoroethane should be handled in a wellventilated environment. Chlorofluorocarbon vapors are heavier than air and do not support life; therefore, when cleaning large tanks that have contained chlorofluorocarbons, adequate provisions for oxygen supply in the tanks must be made in order to protect workers cleaning the tanks. Chlorodifluoroethane is flammable; see Section 10. When heated to decomposition, chlorodifluoroethane emits toxic fumes.
Chlorodifluoromethane. Chlorodifluoromethane Empirical formula CHClF2 Molecular weight 86.47 CAS number [75-45-6] Synonyms Arcton 22; difluorochloromethane; Dyriel 22; Frigen 22; HCFC 22; Isceon 22; P-22; propellant 22; refrigerant 22. Boiling point –40.88C Critical temperature 968C Density 1.19 g/cm3 for liquid at 258C. Melting point –1468C Solubility Freely soluble in acetone, chloroform, and ether; soluble 1 in 330 parts of water at 258C. Vapor density (absolute) 3.860 g/cm3 at standard temperature and pressure. Vapor density (relative) 2.98 (air = 1) Vapor pressure 1041 kPa (151 psia) at 258C; 2137 kPa (310 psia) at 54.58C. Handling precautions The long-term workplace exposure limit (8-hour TWA) for chlorodifluoromethane is 3590 mg/m3 (1000 ppm).(1) Comments Chlorodifluoromethane is a hydrochlorofluorocarbon (HCFC) aerosol propellant used in topical pharmaceutical formulations
Although not used in new formulations, chlorodifluoroethane may still be present in some commercial products. For a discussion of the numerical nomenclature applied to this aerosol propellant, see Chlorofluorocarbons. The PubChem Compound ID (CID) for chlorodifluoroethane is 6388.