1,1,1-Trichloroethane

Source: Wikipedia, the free encyclopedia.
1,1,1-Trichloroethane
Skeletal formula of 1,1,1-trichloroethane
Skeletal formula of 1,1,1-trichloroethane
Space-filling model of 1,1,1-trichloroethane
Space-filling model of 1,1,1-trichloroethane
Names
Preferred IUPAC name
1,1,1-Trichloroethane
Other names
1,1,1-TCA, Methyl chloroform, Chlorothene, Solvent 111, R-140a, Genklene, monochlorethylidene chloride (archaic)
Identifiers
3D model (
JSmol
)
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard
 100.000.688 Edit this at Wikidata
EC Number
  • 200-756-3
82076
IUPHAR/BPS
KEGG
RTECS number
  • KJ2975000
UNII
UN number 2831
  • InChI=1S/C2H3Cl3/c1-2(3,4)5/h1H3 checkY
    Key: UOCLXMDMGBRAIB-UHFFFAOYSA-N checkY
  • InChI=1/C2H3Cl3/c1-2(3,4)5/h1H3
    Key: UOCLXMDMGBRAIB-UHFFFAOYAP
  • ClC(Cl)(Cl)C
Properties
C2H3Cl3 or CH3CCl3
Molar mass 133.40 g/mol
Appearance Colorless liquid
Odor mild, chloroform-like[1]
Density 1.32 g/cm3
Melting point −33 °C (−27 °F; 240 K)
Boiling point 74 °C (165 °F; 347 K)
0.4% (20°C)[1]
0.480 g/litre at 20 °C[2]
Vapor pressure 100 mmHg (20°C)[1]
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
 Ozone layer impact. Irritant to the upper respiratory tract. Causes severe irritation and swelling to eyes.
GHS labelling:
GHS07: Exclamation mark
Warning
H332, H420
P261, P271, P304+P312, P304+P340, P312, P502
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g. chloroformFlammability 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g. canola oilInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
2
1
0
Explosive limits
 7.5%-12.5%[1]
Lethal dose or concentration (LD, LC):
9600 mg/kg (oral, rat)
6000 mg/kg (oral, mouse)
5660 mg/kg (oral, rabbit)[3]
3911 ppm (mouse, 2 hr)
18000 ppm (rat, 4 hr)[3]
NIOSH (US health exposure limits):
PEL (Permissible)
 TWA 350 ppm (1900 mg/m3)[1]
REL (Recommended)
 C 350 ppm (1900 mg/m3) [15-minute][1]
IDLH
(Immediate danger)
 700 ppm[1]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
checkY verify (what is checkY☒N ?)

The

1,1,2-trichloroethane. This colorless, sweet-smelling liquid was once produced industrially in large quantities for use as a solvent.[4] It is regulated by the Montreal Protocol
as an ozone-depleting substance and its use is being rapidly phased out.

Production

1,1,1-Trichloroethane was first reported by Henri Victor Regnault in 1840. Industrially, it is usually produced in a two-step process from vinyl chloride. In the first step, vinyl chloride reacts with hydrogen chloride at 20-50 °C to produce 1,1-dichloroethane:

CH2=CHCl + HCl → CH3CHCl2

This reaction is

catalyzed by a variety of Lewis acids, mainly aluminium chloride, iron(III) chloride, or zinc chloride. The 1,1-dichloroethane is then converted to 1,1,1-trichloroethane by reaction with chlorine under ultraviolet
irradiation:

CH3CHCl2 + Cl2 → CH3CCl3 + HCl

This reaction proceeds at 80-90% yield, and the hydrogen chloride byproduct can be recycled to the first step in the process. The major side-product is the related compound 1,1,2-trichloroethane, from which the 1,1,1-trichloroethane can be separated by distillation.

A somewhat smaller amount of 1,1,1-trichloroethane is produced from the reaction of

1,1-dichloroethene and hydrogen chloride in the presence of an iron(III) chloride
catalyst:

CH2=CCl2 + HCl → CH3CCl3

1,1,1-Trichloroethane is sold with stabilizers because it is unstable with respect to dehydrochlorination and attacks some metals. Stabilizers comprise up to 8% of the formulation, including acid scavengers (epoxides, amines) and

complexants
.

Uses

1,1,1-Trichloroethane is generally considered a non-polar solvent. Owing to the good

aerosol propellant, as a cutting fluid additive, and as a solvent for inks, paints, adhesives, and other coatings. 1,1,1-Trichloroethane was used to dry-clean leather and suede. [5] 1,1,1-Trichloroethane is also used as an insecticidal fumigant
.

It was also the standard cleaner for photographic film (movie/slide/negatives, etc.). Other commonly available solvents damage emulsion and base (

liquid paper. Many of its applications previously used carbon tetrachloride (which was banned in US consumer products in 1970). In turn, 1,1,1-trichloroethane itself is now being replaced by other solvents in the laboratory.[6]

Anaesthetic research

1,1,1-Trichloroethane was one of the volatile organochlorides that have been tried as alternatives to chloroform in anaesthesia.[7] In the 1880s, it was found to be a safe and strong substitute for chloroform[8] but its production was expensive and difficult.[9]

In 1880, 1,1,1-Trichloroethane was suggested as an anaesthetic. It was first referred to as "methyl-chloroform" in the same year. At the time, the narcotic effects of

1,1,2-trichloroethane isomer, which lacked a trichloromethyl group, exhibited anaesthetic effects even stronger than the 1,1,1 isomer.[10]

Safety

Although not as

Proposition 65 declaring it hazardous and toxic.[16][17]

Prolonged skin contact with the liquid can result in the removal of fats from the skin, resulting in skin irritation.

The International Agency for Research on Cancer places 1,1,1-trichloroethane in Group 2A as a probable carcinogen.[18]

Atmospheric concentration

1,1,1-Trichloroethane (Methyl chloroform, CH3CCl3) measured by the Advanced Global Atmospheric Gases Experiment (AGAGE) in the lower atmosphere (troposphere) at stations around the world. Abundances are given as pollution free monthly mean mole fractions in parts-per-trillion.
1,1,1-Trichloroethane timeseries at various latitudes.

The Montreal Protocol targeted 1,1,1-trichloroethane as one of those compounds responsible for ozone depletion and banned its use beginning in 1996. Since then, its manufacture and use have been phased out throughout most of the world. Its atmospheric presence has declined rapidly due to its relatively short atmospheric lifetime of about 5 years.[19]

References

  1. ^ a b c d e f g NIOSH Pocket Guide to Chemical Hazards. "#0404". National Institute for Occupational Safety and Health (NIOSH).
  2. ^ "International Programme On Chemical Safety, Environmental Health Criteria 136". World Health Organization, Geneva. 1990. Retrieved 2017-12-25.
  3. ^ a b "Methyl chloroform". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
  4. doi:10.1002/14356007.a06_233.pub2
    .
  5. ^ Morrison, R. D., Murphy, B. L. (2013). Chlorinated Solvents: A Forensic Evaluation. UK Royal Society of Chemistry. Page 203
  6. ^ Use of Ozone Depleting Substances in Laboratories. TemaNord 516/2003 Archived 2008-02-27 at the Wayback Machine
  7. ^ The American Practitioner 1881-01: Volume 23, page 28
  8. ^ Methyl-Chloroform (1887) in Saint Louis Medical and Surgical Journal, page 121
  9. ^ An introduction to modern therapeutics (1892), Brunton, T. Lauder, page 122
  10. ^ On Two New Anaesthetics (1880), The American Journal of Pharmacy 1881-03: Vol 53, pages 119–120
  11. ^ Toxicological Profile for 1,1,1-Trichloroethane Archived 2008-05-09 at the Wayback Machine, Agency for Toxic Substances and Disease Registry (ATSDR). 2006
  12. PMID 3974043. Archived
    from the original on 2013-02-23. Retrieved 2010-01-05. We describe four cases of sudden death in adolescents associated with recreational sniffing of typewriter correction fluid occurring during the period 1979 through mid-1984.
  13. PMID 2231588
    .
  14. PMID 9237378
    . A 13-year-old male was found dead in the woods subsequent to 1,1,1-trichloroethane (TCE) inhalation.
  15. PMID 2908837. Archived
    from the original on 2013-04-14. Retrieved 2010-01-05.
  16. ^ Paddock, Richard C. (29 September 1989). "Gillette Agrees to Remove Toxics From Its Paper Correction Fluid". Los Angeles Times. Sacramento. Archived from the original on 15 July 2012. Retrieved 5 January 2010.
  17. ISBN 0-8247-7516-3
    . Retrieved 5 January 2010. Gillette agreed to reformulate the product so that it would not pose a risk requiring a Proposition 65 warning
  18. ISBN 978-92-832-0197-7
    .
  19. ^ "Chapter 8, Table 8.A.1". AR5 Climate Change 2013: The Physical Science Basis. p. 733.

Further reading

  • Doherty, R.E. (2000). "A History of the Production and Use of Carbon Tetrachloride, Tetrachloroethylene, Trichloroethylene and 1,1,1-Trichloroethane in the United States: Part 2 - Trichloroethylene and 1,1,1-Trichloroethane". Environmental Forensics. 1 (2): 83–93.
    S2CID 97370778
    .
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