Dichlorofluoromethane

Names
Preferred IUPAC name Dichloro(fluoro)methane
Other names Dichlorofluoromethane Fluorodichloromethane Monofluorodichloromethane Dichloromonofluoromethane Freon 21 Refrigerant 21 R 21 HCFC 21 Algofrene Type 5 Arcton 7 Halon 112 UN 1029 Genetron 21
Identifiers
CAS Number	75-43-4 Y
3D model (JSmol)	Interactive image
ChEMBL	ChEMBL116813 Y
ChemSpider	6130 Y
ECHA InfoCard	100.000.791
EC Number	200-869-8
PubChem CID	6370
RTECS number	PA8400000
UNII	7GAO4CRJ0B Y
UN number	1029
CompTox Dashboard (EPA)	DTXSID7052498
InChI InChI=1S/CHCl2F/c2-1(3)4/h1H Y Key: UMNKXPULIDJLSU-UHFFFAOYSA-N Y InChI=1/CHCl2F/c2-1(3)4/h1H Key: UMNKXPULIDJLSU-UHFFFAOYAU
SMILES ClC(Cl)F
Properties
Chemical formula	CHCl2F
Molar mass	102.92 g/mol
Appearance	Colorless gas
Odor	Ether-like[1]
Density	1.405 kg/m3 at 9 °C 1.366 kg/m3 at 25 °C
Melting point	−135 °C (−211 °F; 138 K)
Boiling point	8.92 °C (48.06 °F; 282.07 K)
Solubility in water	9.420 g/L at 30 °C
log P	1.55
Vapor pressure	160 kPa
Henry's law constant (kH)	0.19 (mol·kg·bar)−1
Magnetic susceptibility (χ)	−48.8·10−6 cm3/mol
Thermal conductivity	0.0086 W/m·K (300 K)[2]
Hazards
GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H280, H420
Precautionary statements	P410+P403, P502
Flash point	Non-flammable[1]
Autoignition temperature	522 °C (972 °F; 795 K)
Lethal dose or concentration (LD, LC):
LC50 (median concentration)	>800,000 mg/m3 (mouse, 2 hr) 49,900 ppm (rat, 4 hr)[3]
LCLo (lowest published)	100,000 ppm (guinea pig, <1 hr) 100,000 ppm (mouse, <1 hr)[3]
NIOSH (US health exposure limits):
PEL (Permissible)	TWA 1000 ppm (4200 mg/m3)[1]
REL (Recommended)	TWA 10 ppm (40 mg/m3)[1]
IDLH (Immediate danger)	5000 ppm[1]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is YN ?) Infobox references

Dichlorofluoromethane or Freon 21 or R 21 is a halomethane or hydrochlorofluorocarbon with the formula CHCl₂F. It is a colorless and odorless gas. It is produced by fluorination of chloroform using a catalyst such as antimony trifluoride:^[4]

CHCl₃ + HF → CHCl₂F + HCl

Dichlorofluoromethane was used as a propellant and refrigerant. Due to its role in ozone depletion, dichlorofluoromethane has been largely phased out. It has ozone depletion potential 0.04. Production and consumption has been since 2004 reduced to 15% of level from 1989 and it is to be phased out in 2015 according to Montreal Protocol.

Pyrolysis of a mixture of dichlorofluoromethane and chlorofluoromethane gives hexafluorobenzene:^[4]

3 CHCl₂F + 3 CH₂ClF → C₆F₆ + 9 HCl

Its critical point is at 178.5 °C (451.7 K) and 5.17 MPa (51.7 bar). At temperatures from 5 K to 105 K, it has one phase in the space group Pbca.

Its toxicity is comparable to that of chloroform. Its TLV is 10 ppm.^[4]

• International Chemical Safety Card 1106
• NIOSH Pocket Guide to Chemical Hazards. "#0197". National Institute for Occupational Safety and Health (NIOSH).
• Termochemistry data at chemnet.ru
• Entry at Air Gas Liquide Encyclopaedia Archived 2021-02-18 at the Wayback Machine