Halogenated Volatile Organic Compounds

O’Doherty, Simon; Carpenter, Lucy J.

doi:10.1002/9780470988657.ch5

Cited by 8 publications

(8 citation statements)

References 116 publications

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“…The above implies that the atmospheric lifetime not only determines the global average concentration (or surface mixing ratio) of the organic compound in the atmosphere (seen in Table 5 ), but also plays an important role in the ozone variations of the troposphere and stratosphere, and the impacts on regional air quality and climate change. Table 5 summarizes the common environmental properties of the four chloromethanes, including CH 3 Cl, CH 2 Cl 2 , CHCl 3 , and CCl 4 [ 13 , 30 , 31 , 32 , 33 , 34 ]. These chlorinated compounds contain C-H and C-Cl bands with characteristic infrared (IR) absorption patterns in the atmosphere, suggesting that they are greenhouse gases, tropospheric ozone precursors, and stratospheric ozone-depleting initiators.…”

Section: Atmospheric Fate Of Chloromethanesmentioning

confidence: 99%

“… a Source [ 33 ]; b Source [ 33 , 34 ]; c Global warming potential with a 100-year time horizon (relative to GWP of CO 2 = 1.0); source [ 33 ]; d Ozone depletion potential (relative to the ODP of CFC-11 = 1.0); source [ 13 , 32 ]; e Photochemical ozone creation potential (relative to POCP of ethene = 100); source [ 31 ]; f Source [ 13 , 30 , 32 ]. …”

Section: Tablementioning

confidence: 99%

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Fate of Chloromethanes in the Atmospheric Environment: Implications for Human Health, Ozone Formation and Depletion, and Global Warming Impacts

Tsai

2017

Toxics

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Among the halogenated hydrocarbons, chloromethanes (i.e., methyl chloride, CH3Cl; methylene chloride, CH2Cl2; chloroform, CHCl3; and carbon tetrachloride, CCl4) play a vital role due to their extensive uses as solvents and chemical intermediates. This article aims to review their main chemical/physical properties and commercial/industrial uses, as well as the environment and health hazards posed by them and their toxic decomposition products. The environmental properties (including atmospheric lifetime, radiative efficiency, ozone depletion potential, global warming potential, photochemical ozone creation potential, and surface mixing ratio) of these chlorinated methanes are also reviewed. In addition, this paper further discusses their atmospheric fates and human health implications because they are apt to reside in the lower atmosphere when released into the environment. According to the atmospheric degradation mechanism, their toxic degradation products in the troposphere include hydrogen chloride (HCl), carbon monoxide (CO), chlorine (Cl2), formyl chloride (HCOCl), carbonyl chloride (COCl2), and hydrogen peroxide (H2O2). Among them, COCl2 (also called phosgene) is a powerful irritating gas, which is easily hydrolyzed or thermally decomposed to form hydrogen chloride.

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Section: Atmospheric Fate Of Chloromethanesmentioning

confidence: 99%

Section: Tablementioning

confidence: 99%

Fate of Chloromethanes in the Atmospheric Environment: Implications for Human Health, Ozone Formation and Depletion, and Global Warming Impacts

Tsai

2017

Toxics

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“…chloromethyl chloroacetate and 2-chloroethenyl-1,3-butadiene in <PM 1 and PM 10-2.5 , correspondingly. According to O'Doherty and Carpenter (2007), chlorine is the most abundant halocarbon in the atmosphere and sources of these compounds can be natural and anthropogenic. Natural sources of chlorine consist of sea salt, whereas anthropogenic sources are primarily manufactured compounds, mainly chlorofluororcarbons (CFCs), carbon tetrachloride (CCl 4 ), hydrochlorofluorocarbon (HCFC) and methyl chloroform (WMO/UNEP 1998).…”

Section: Halogenated Organic Compoundsmentioning

confidence: 99%

Size-resolved characterisation of organic compounds in atmospheric aerosols collected at Welgegund, South Africa

et al. 2015

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The organic fraction of atmospheric aerosols is 20 to 90 % of which only a small percentage has been chemically characterised. Two-dimensional gas chromatography with a time-of-flight mass spectrometer (GCxGC-TOFMS) is a powerful instrument used to chemically characterise organic compounds. Size-resolved characterisation and semi-quantification of ambient organic aerosol compounds were performed with a GCxGC-TOFMS for the first time in South Africa. Twenty-four-hour samples were collected for 1 year for three different size ranges. A combined total of 1056 different organic compounds could be tentatively characterised. The largest number of organic compounds tentatively identified was PM 2.5-1 (particles in the size range 1-2.5 μm), while this size fraction also had the highest total number of normalised response factors (∑NRF). On average, 52, 26, 6, 13 and 3 % of species tentatively identified were oxygenated species, hydrocarbons, halogenated compounds, Ncontaining compounds and S-containing compounds, respectively. Oxygenated compounds were the most abundant species. Alkane and mono-aromatic species were the largest number of hydrocarbons tentatively identified with the highest ∑NRFs. The largest number of oxygenated species tentatively characterised were carboxylic acids and esters, while ether compounds had the highest ∑NRFs. Most of the halogenated compounds tentatively identified were chlorinated species with the highest ∑NRFs in two size fractions. Iodate species had a significantly higher ∑NRF in the PM 2.5-1 size fraction. The largest number of N-containing J Atmos Chem species tentatively characterised with the highest ∑NRFs were amines. A small number of Scontaining compounds with low ∑NRFs were tentatively identified. The major sources of organic compounds measured at Welgegund were considered to be biomass burning and air masses moving over the anthropogenically impacted source regions.

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“…Small polyhalogenated alkanes, commonly known as CFC gases, and their decay processes are of major interest because of their environmental impact on the atmosphere . CH 2 Cl 2 is applied in large quantities for industrial purposes such as decaffeination, and while it is moderately reactive in the atmosphere, , it can persist in the oceans for decades .…”

Section: Introductionmentioning

confidence: 99%

Electronic Predissociation in the Dichloromethane Cation CH₂Cl₂⁺ Electronic State ²A₁

et al. 2019

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The loss of a Cl atom from metastable CH2Cl2 + in the mass-analyzed ion kinetic energy experiment is characterized by a borderline zero kinetic energy release and large kinetic isotope effects on chlorine and hydrogen. Ab initio calculations are employed to assist the interpretation in terms of a nonadiabatic reaction involving electronic predissociation of the electronically excited state 2A1 and two-dimensional reaction dynamics. Strong curvature in the reaction coordinate leads to a bobsled effect that accounts for the low kinetic energy release. The kinetic isotope effects enter via the predissociation rate and are interpreted in terms of vibrational overlap integrals.

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Halogenated Volatile Organic Compounds

Cited by 8 publications

References 116 publications

Fate of Chloromethanes in the Atmospheric Environment: Implications for Human Health, Ozone Formation and Depletion, and Global Warming Impacts

Fate of Chloromethanes in the Atmospheric Environment: Implications for Human Health, Ozone Formation and Depletion, and Global Warming Impacts

Size-resolved characterisation of organic compounds in atmospheric aerosols collected at Welgegund, South Africa

Electronic Predissociation in the Dichloromethane Cation CH₂Cl₂⁺ Electronic State ²A₁

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Halogenated Volatile Organic Compounds

Cited by 8 publications

References 116 publications

Fate of Chloromethanes in the Atmospheric Environment: Implications for Human Health, Ozone Formation and Depletion, and Global Warming Impacts

Fate of Chloromethanes in the Atmospheric Environment: Implications for Human Health, Ozone Formation and Depletion, and Global Warming Impacts

Size-resolved characterisation of organic compounds in atmospheric aerosols collected at Welgegund, South Africa

Electronic Predissociation in the Dichloromethane Cation CH2Cl2+ Electronic State 2A1

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Electronic Predissociation in the Dichloromethane Cation CH₂Cl₂⁺ Electronic State ²A₁