# NIOSH Pocket Guide to Chemical Hazards
Dichloromonofluoromethane | CAS 75-43-4
CHCl2F | RTECS PA8400000
Synonyms & Trade Names Dichlorofluoromethane, Fluorodichloromethane, Freon® 21, Genetron® 21, Halon® 112, Refrigerant 21 | DOT ID & Guide 1029 126
Exposure Limits | NIOSH REL: TWA 10 ppm (40 mg/m3)
OSHA PEL†: TWA 1000 ppm (4200 mg/m3)
IDLH 5000 ppm | Conversion 1 ppm = 4.21 mg/m3
Physical Description Colorless gas with a slight, ether-like odor. [Note: A liquid below 48°F. Shipped as a liquefied compressed gas.]
MW: 102.9 | BP: 48°F | FRZ: -211°F | Sol(86°F): 0.7%
VP(70°F): 1.6 atm | IP: 12.39 eV | RGasD: 3.57 |
Fl.P: NA | UEL: NA | LEL: NA |
Nonflammable Gas
Incompatibilities & Reactivities Chemically-active metals such as sodium, potassium, calcium, powdered aluminum, zinc & magnesium; acid; acid fumes
Measurement Methods NIOSH 2516
Personal Protection & Sanitation Skin: Frostbite Eyes: Frostbite Wash skin: No recommendation Remove: No recommendation Change: No recommendation Provide: Frostbite | First Aid (See procedures) Eye: Frostbite Skin: Frostbite Breathing: Respiratory support
Respirator Recommendations NIOSH Up to 100 ppm: (APF = 10) Any supplied-air respirator Up to 250 ppm: (APF = 25) Any supplied-air respirator operated in a continuous-flow mode Up to 500 ppm: (APF = 50) Any self-contained breathing apparatus with a full facepiece/(APF = 50) Any supplied-air respirator with a full facepiece Up to 5000 ppm: (APF = 1000) Any supplied-air respirator operated in a pressure-demand or other positive-pressure mode Emergency or planned entry into unknown concentrations or IDLH conditions: (APF = 10,000) Any self-contained breathing apparatus that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode/(APF = 10,000) Any supplied-air respirator that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode in combination with an auxiliary self-contained positive-pressure breathing apparatus Escape: (APF = 50) Any air-purifying, full-facepiece respirator (gas mask) with a chin-style, front- or back-mounted organic vapor canister/Any appropriate escape-type, self-contained breathing apparatus
Exposure Routes inhalation, skin and/or eye contact (liquid)
Symptoms Asphyxia, cardiac arrhythmias, cardiac arrest; liquid: frostbite
Target Organs respiratory system, cardiovascular system
See also: INTRODUCTION