Bromochloromethane

Bromochloromethane
File:Bromochloromethane.svg	File:Bromochloromethane-3D-sf.png
IUPAC name Bromochloromethane
Other names Monochloromonobromomethane, Bromo(chloro)methane, Chloromethyl bromide, Methylene chlorobromide, Methylene bromochloride, Borothene, Halon 1011, BCM, CBM, UN 1887
style="background: #F8EABA; text-align: center;" colspan="2" | Identifiers
CAS number	74-97-5 Y
PubChem	6333
ChemSpider	6093
EC number	200-826-3
KEGG	C02661
ChEBI	17194
RTECS number	PA5250000
SMILES
InChI
InChI key	JPOXNPPZZKNXOV-UHFFFAOYAI
style="background: #F8EABA; text-align: center;" colspan="2" | Properties
Molecular formula	CH2BrCl
Molar mass	129.38 g/mol
Appearance	Colorless to yellow liquid with chloroform-like odor
Density	1.9344 g/cm3 at 20 °C
Melting point	-86.5 °C
Boiling point	68.1 °C
Solubility in water	16.7 g/l
Vapor pressure	15.6 kPa at 20 °C
style="background: #F8EABA; text-align: center;" colspan="2" | Hazards
R-phrases	R37, R38, R41, R59
S-phrases	S26, S39, S59
Y (what is this?)  (verify) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Bromochloromethane or methylene bromochloride and Halon 1011 is a mixed halomethane. It is a heavy low-viscosity liquid with refractive index 1.4808.

It was invented for use in fire extinguishers by the Germans during the mid-40s, in an attempt to create a less-toxic, more effective alternative to carbon tetrachloride. This was a concern in aircraft and tanks as carbon tetrachloride produced highly toxic by-products when discharged onto a fire. CBM was slightly less toxic, and used up until the late 1960s, being officially banned by the NFPA for use in fire extinguishers in 1969, as safer and more effective agents such as halon 1211 and 1301 were developed. Due to its ozone depletion potential its production was banned from 1 January 2002 at the Eleventh Meeting of the Parties for the Montreal Protocol on Substances that Deplete the Ozone Layer.

File:Aircraft A-20 CBM.jpg

A 1950s US CBM fire extinguisher.

It can be biologically decomposed using hydrolase enzyme alkylhalidase by the reaction:

CH₂BrCl (l) + H₂O (l) → CH₂O (l) + Br₂ (l) + Cl₂ (g)

In fiction

In the Enter the Matrix video game, the player can find a "Chloro-Bromo Methane Gun", which is used as a fire extinguisher. It fires a pressurized cartridge of CBM gas to put out fires. However, due to its chemical properties, firing a cartridge near people causes their lungs to fill with liquid, effectively drowning them.

External links

• International Chemical Safety Card 0392
• NIOSH Pocket Guide to Chemical Hazards 0123
• MSDS at Oxford University
• MSDS at Oxford University (deuterated bromochloromethane)
• Notice with Respect to n-Propyl Bromide and Bromochloromethane
• Chemical fact sheet
• Data sheet at arbemarle.com

de:Bromchlormethan