1,1,1 -trichloroethane ozone depletion

Finally, nitromethane has been used in large quantities as a stabilizer for 1,1,1-trichloroethane. The use of this degreasing solvent is expected to decHne and disappear under the provisions of the Montreal Protocol (116), which bans ozone-depleting substances, of which this is one. 

Does the Toller use a primary ozone depleting compound (ODC, for example, a CFC or 1,1,1, -trichloroethane) m their process Are ODC management practices followed (for example no uncontrolled releases of ODCs, installation of capture and recycle equipment, leak detection and repair, use of well trained personnel) ... 

A separate set of processibility issues involves health, safety, and environmental concerns. Ozone-depleting compounds (ODCs), such as trichloroethane and... 

There now exist alternatives or sufficient quantities of controlled substances for almost all applications of ozone-depleting solvents. Exceptions have been noted for certain laboratory and analytical uses and for manufacture of space shuttle rocket motors. HCFCs have not been adopted on a large scale as alternatives to CFC solvents. In the near term, however, they may be needed as the conventional substances in some limited and unique applications. HCFC-141b is not a good replacement for methyl chloroform (1,1,1 -trichloroethane) because its ODP is three times higher. Alternatives for specific uses of ozone-depleting solvents are briefly described below. 

An overview of the reactions involving trihalomethanes (haloforms) CHXYZ, where X, Y, and Z are halogen atoms, has been given in the context of ozone depletion (Hayman and Derwent 1997). Interest in the formation of trichloroacetaldehyde formed from trichloroethane and tetrachloroethene is heightened by the phytotoxicity of trichloroacetic acid (Frank et al. 1994), and by its occurrence in rainwater that seems to be a major source of this contaminant (Muller et al. 1996). The situation in Japan seems, however, to underscore the possible significance of other sources including chlorinated wastewater (Hashimoto et al. 1998). Whereas there is no doubt about the occurrence of trichloroacetic acid in rainwater (Stidson et al. 2004), its major source is unresolved since questions remain on the rate of hydrolysis of trichloroacetaldehyde (Jordan et al. 1999). 

Ozone depleters (e.g. CFCs, 1,1,1-trichloroethane) Least acceptable Toxic and carcinogenic solvents (CCI4, benzene)... 

Generally considered to be among the least toxic of the alkyl halides, 1,1,1-trichloroethane was once produced at levels of several hundred million kilograms per year. However, it is persistent in the atmosphere and is a strong stratospheric ozone-depleting chemical, so production has been severely curtailed and there is now little reason for concern over its toxicity. 

Trichloroethane was a major solvent, particularly for cold and vapor degreasing. It was phased out for emissive uses in the United States in 1996 because of its ozone depletion potential. The only application left is as chemical precursor for HCFC-141b and HCFC-142b. However, both are subject to phaseout schedule of the Montreal Protocol,... 

Many of the commonly used solvents for precision cleaning are being eliminated due to their suspected involvement in reduction of the earth s ozone layer. Production of these chemicals, known as ozone depleting substances (ODS), is being eliminated by an international treaty known as the Montreal Protocol. This is an international agreement, first proposed in 1987 and entered into force in 1989, which limits production of chlorofluorocarbons (CFCs) and halons due to concerns that these substances were damaging the earth s ozone layer. The Montreal Protocol was modified in 1990 and again in 1992 to completely eliminate the production of chlorofluorocarbons, carbon tetrachloride, methyl chloroform (1,1,1 -trichloroethane) and halons by 1996. 

In September 1991 Statikil, Inc., Akron, OH announced the reformulation of its Statikil antistatic agents, which no longer contain the ozone-depleting 1,1,1-trichloroethane (6). 

Catalytic hydrotreatment is widely used in the petroleum Industry to remove sulfur, nitrogen, and oxygen from crude oil fractions. However, its use to treat chlorocarbons has not been widely reported despite the widespread use of these compounds in industrial and military operations, and despite the negative environmental impact associated with most disposal options. Catalytic hydrotreatment has the potential to be a safe alternative for the treatment of chlorinated wastes and has advantages over oxidative destruction methods such as thermal incineration and catalytic oxidation. Some of these advantages include the ability to reuse the reaction products, and minimal production of harmful byproducts, such as CI2, COCI2, or fragments of parent chlorocarbons. 1,1,1- Trichloroethane was chosen for this research because it is widely used in industry as a solvent and is on the EPA Hazardous Air Pollutant list as a toxic air contaminant and ozone depleter. ... 

Features Non-VOC, non-ozone depleting 1,1,1-trichloroethane alternative VOC-exempt status Regulatory SARA nonreportable... 

Features Non-ozone depleting 1,1,1 -trichloroethane alternative not hazardous waste... 

Uses Non-ozone depleting solvent for industrial solvent cleaning, aerosols, adhesives, coatings, inks, electronic applies. 1,1,1-trichloroethane alternative dye intermediate chemical intermediate dielec, fluid Manuf./Distrib. Aldrich Fluka Occidental Sigma Trade Names Oxsol 100... 

Vertrel KCD-9547 is a proprietary azeotrope-like blend of Vertrel XF hydrofluorocarbon with trans-1,2-dichioro-ethylene and cyclopentane. It is ideally suited for use in vapor degreasing equipment to remove light oils, fingerprints, and particulate contaminants. Vertrel KCD-9547 is specially formulated to provide a high degree of compatibility with plastics, elastomers, and other nonferrous metals, such eis in aerospace parts. Vertrel KCD-9547 is nonflammable, has "zero" ozone depletion potential, and heis low global warming potential. It can replace CFC-113,1,1,1 -trichloroethane (1,1,1 -TCA), hydrochlorofluorocarbons (HCFC), and perfluorocarbons (RFC) in many applications. 

Montreal Protocol on Substances that Deplete the Ozone Layer. An international agreement signed by almost all industrialized nations which sets a phase out for the production of ozone depleting substances (ODS s). The compounds to be phased out include chlorofluorocarbons (CFC s), halons, carbon tetrachloride, methyl chloroform (1,1,1-trichloroethane), and hydrochlorofluorocarbons (HCFC s). The original phaseout dates were revised in the 1992 modification of the Montreal Protocol, morbidity. Rate of incidence of disease. 

Some halogenated solvents (carbon tetrachloride, 1,1,1-trichloroethane), along with chlorofluorocarbons (CFCs) and hydrofluorocarbons (HCFCs) are very stable in the lower atmosphere and can reach the stratosphere where they contribute to the problem of ozone depletion. Almost worldwide agreement has been reached to eliminate the manufacture and use of these materials. 

Stratospheric ozone depletion as a result of the reaction of certain chlorinated hydrocarbons (e.g. CFCs, HCFCs, CCI4, trichloroethane) with ozone. 

The first of these issues, stratospheric ozone depletion, is caused by certain halogenated materials, some of which (CTC and 1,1,1-trichloroethane) are still used as solvents. 

The second tier solvents are more harmful to health and environment than the first five most frequently released and transferred solvents. Ketones are suspected carcinogens by some sources. Dichloromethane is a probable human carcinogen. 1,1,1-trichloroethane is an ozone depleter. Because of their volatility, these solvents reside mostly in the lower atmosphere causing pollution and participating in radical processes. 

CAAA-90, Title VI (Stratospheric Ozone Protection), will not affect coatings much because chlorofluorocarbons are not used. One interesting case is 1,1,1-trichloroethane (TCE). Since TCE is VOC exempt, its use in coatings increased significantly in the late 1970s. Later it was fonnd that TCE contributes to stratospheric ozone depletion, and therefore it is on the HAPs list. Title VI provides staged phase out of TCE use as a solvent. 

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