Halocarbons trichloroethylene

Another study found that trichloroethylene can be absorbed from the atmosphere by foods and concentrated over time, so that acceptable ambient air levels may still result in food levels which exceed acceptable limits (Grob et al. 1990). The authors estimated that in order to limit food concentrations of trichloroethylene to 50 pg/kg (the maximum tolerated limit for food halocarbons in Switzerland), the level in surrounding air should not exceed 38.5 pg/m (0.007 ppm). Since the accepted levels found near emission sources are often far above this limit, foods processed or sold near these sources may routinely exceed the tolerated trichloroethylene concentration, thus making the setting of air emission standards problematic. It is also noteworthy that the limits recommended by Grob et al. (1990) exceed acceptable ambient air concentrations for many regions of the United States (see Chapter 7). 

See Dinitrogen tetraoxide Halocarbons Oxygen (Gas) Halocarbons Oxygen (Liquid) Halocarbons Perchloric acid Trichloroethylene... 

Similarly, our forcefield works equally well for unsaturated halocarbons. For example, calorimetric heats of adsorption for trichloroethylene in the same three faujasite zeolites are in excellent agreement with our (N.V.T) Monte Carlo simulations [16]. Our results at "zero" loading suggest, unlike hydrocarbons, an analogy between the adsorption processes of saturated and unsaturated halocarbons. 

Interestingly, the interactions between zeolites and unsaturated chlorocarbons like trichloroethylene (TCE) are found to be strikingly different from those between zeolites and unsaturated hydrocarbons (i.e. ethylene and benzene). Both our simulations and our spectroscopic results on the adsorption of TCE in faujasites show that interactions between the n electrons and the cations, which dominate in the case of hydrocarbons, are replaced by interactions between the chlorine atoms and the cations [18]. Figure 3 shows typical positions of TCE in NaY zeolite as predicted by energy minimizations. This is a consequence of the different charge distribution in hydrocarbons and halocarbons. 

Mixtures of lithium shavings and several halocarbon derivatives are impact-sensitive and will explode, sometimes violently [1,2]. Such materials include bromoform, carbon tetrabromide, carbon tetrachloride, carbon tetraiodide, chloroform, dichloromethane, diiodomethane, fhiorotrichloromethane, tetrachloroethylene, trichloroethylene and 1,1,2-trichlorotrifluoroethane. In an operational incident, shearing samples off a lithium billet immersed in carbon tetrachloride caused an explosion and continuing combustion of the immersed metal [3]. Lithium which had been washed in carbon tetrachloride to remove traces of oil exploded when cut with a knife. Hexane is recommended as a suitable washing solvent [4]. A few drops of carbon tetrachloride on burning lithium was without effect, but a 25 cc portion caused a violent explosion [5]. 

Halocarbons. Powdered beryllium in carbon tetrachloride or trichloroethylene will ignite on heavy impact.2... 

Halocarbons. Forms explosive mixtures with bromoform, carbon tetra-bromide, -chloride, and -iodide, chloroform, dichloro- and diiodomethane, fluorotrichloromethane, tetrachloroethylene, trichloroethylene, and 1,1,2-trichlorotrifluoroethane3-5 may explode when washed with carbon tetrachloride, and then cut with a knife hexane should be used for washing.3... 

Halocarbons. A vigorous and sometimes explosive reaction occurs on contact of Mg powder with chloromethane, chloroform, or carbon tetrachloride with carbon tetrachloride or trichloroethylene, heavy impact causes ignition with 1,1,1-trichloroethane, violent decomposition occurs.5... 

SAFETY PROFILE Confirmed carcinogen with experimental carcinogenic, neoplastigenic, and tumorigenic data. A deadly poison by intravenous route. Human systemic effects by inhalation lung fibrosis, dyspnea, and weight loss. Human mutation data reported. See also BERYLLIUM COMPOUNDS. A moderate fire hazard in the form of dust or powder, or when exposed to flame or by spontaneous chemical reaction. Slight explosion hazard in the form of powder or dust. Incompatible with halocarbons. Reacts incandescently with fluorine or chlorine. Mixtures of the powder with CCU or trichloroethylene will flash or spark on impact. When heated to decomposition in air it emits very toxic fumes of BeO. Reacts with Li and P. 

Explosive reaction with bromobenzene, carbon + lithium tetrachloroaluminate + sulfinyl chloride, diazomethane. Forms very friction- and impact-sensidve explosive mixtures with halogens (e.g., bromine, iodine (above 200°C)), halocarbons (e.g., bromoform, carbon tetrabromide, carbon tetrachloride, carbon tetraiodide, chloroform, dichloromethane, diiodomethane, fluorotrichloromethane, tetrachloroethydene, trichloroethylene, 1,1,2-trichloro-trifluoroethane). 

Certain halocarbons such as methylene chloride, trichloroethylene, (TCE) and fluorocarbons can be used as a secondary cooling medium at temperatures lower than — 50°C. These fluids are nonflammable and non-corrosive under normal operating conditions. However, chlorinated compounds such as methylene chloride or TCE are very toxic and regulated by the Environmental Protection Agency (EPA). So, these fluids will be removed from the existing systems in the next few years. 

Chang JS, Kaufman F. 1977. Kinetics ofthe reactions of hydroxyl radicals with some halocarbons Dichlorofluoromethane, chlorodifluoromethane, trichloroethane, trichloroethylene, and tetrachloroethylene. J Chem Phys 66 4989-4994. 

BERILIO (Spanish) (7440-41-7) Powder forms explosive mixture in air. Contact with acids or alkalis causes evolution of explosive hydrogen gas. Forms shock-sensitive mixtures with some chlorinated solvents, such as carbon tetrachloride and trichloroethylene. Violent reaction with chlorine, fluorine, lithium, phosphorus. Incompatible with alkalis, chlorinated hydrocarbons, halocarbons, oxidizable agents, oxidizers. 

HAZARD RISK Non-combustible solid moderate fire hazard in the form of powder moderate fire hazard when exposed to flame or by spontaneous chemical reaction incompatible with halocarbons reacts incandescently with fluorine or chlorine decomposition emits toxic fumes of beryllium oxide reacts with strong acids and strong bases forming combustible gas forms shock sensitive mixtures with some chlorinated solvents including carbon tetrachloride and trichloroethylene NFPA code H3 FI RO. 

Trichloroethylene. See Trichloroethylene 1,r-(2,2,2-Trichloroethylidene) bis (4-methoxybenzene). See Methoxychlor Trichloro ethylidene glycol. See Chloral hydrate Tri (2-chloroethyl) phosphate Tri-P-chloroethyl phosphate. See Tris (P-chloroethyl) phosphate Trichloroethylsilane Trichloroethylsilicane. See Ethyltrichlorosilane Trichlorofluoromethane CAS 75-69-4 EINECS/ELINCS 200-892-3 Synonyms CFC 11 F11 FC11 Fluorocarbon 11 Fluorotrichloromethane Freon 11 Freon HE Halocarbon 11 Methane, trichlorofluoro- Monofluorotrichloromethane Propellant 11 R11 Trichloromonofluoromethane Classification Halogenated aliphatic hydrocarbon... 

Some of the more important industries that produce solvent-contained air streams are printing dry cleaning and the manufacture of paints, polymers, adhesives, celluloid, rubber (e.g., rubber-coated fabrics), rayon, and gunpowder and extraction processes. The main solvents recovered by activated carbon adsorption are benzene, toluene, xylene, alcohols, acetone, petrol, ether, carbon disulfide, halocarbons (e.g., chloroform, carbon tetrachloride, trichloroethylene, methylene chloride, chlorobenzene, etc.). The major production facilities and the solvents recovered are listed in Table 5.3. In many cases the concentration of the organic solvent in waste gases is of the order of 1 to 2%. 

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