1,2-Ethylene dibromide

Ethylene dibromide (EDB) is used extensively as a soil and postharvest fumigant for crops and as a quarantine fumigant for citrus, tropical fruits, and vegetables. It also may be used as a gas in termite and Japanese beetle control, beehive and vault fumigation, and spot fumigation of milling machinery. 

The acute exposure of EDB caused toxic effects in animals and produced severe skin burning. The acute oral toxicity to the male rat is approximately 146 mg/kg, and the acute vapor toxicity is 200 ppm. Prolonged exposure to vapor of EDB (210 mg/m3) of 7 hours/day, 5 days/week for 6 months was found to be tolerated by rats. EDB of single application on the skin has caused severe burning effects. The acute oral toxicity (LD50) in males was found to be 146 mg/kg, and the acute inhalation of the vapor was 200 ppm. 

LABORATORY CHEMICAL SAFETY SUMMARY ETHYLENE DIBROMIDE  

Substance Ethylene dibromide (1,2-Dibromoethane, ethylene bromide, EDB) CAS 106-93-4 

Toxicity Data LD50 oral (rat) 108 mg/kg LD50 skin (rabbit) 300 mg/kg LC50 inhal (rat) 14,300 mg/m (30 min) PEL(OSHA) 20ppm(150mg/m5) 

Major Hazards Suspected human carcinogen (OSHA select carcinogen ) moderate acute toxicity severe skin and eye irritant. 

Flammability and Explosibility Ethylene dibromide is a noncombustible substance (NFPA rating = 0). 

A study of EDA-sensitized workers (as determined by EDA-associated rhinitis, coughing, and wheezing) in an industrial population suggested that smoking may decrease the latency between first exposure to EDA and onset of respiratory symptoms.  

Exposure of rats to 4000 ppm for 8 hours was uniformly fatal, whereas 2000 ppm was not lethal. Rats exposed daily for 30 days to 484 ppm did not survive injury to lungs, liver, and kidneys was observed at 132 ppm there was no mortality.  

In chronic studies nonneoplastic effects on the liver (pleomorphic changes to hepatocytes) have been observed in rats after oral dosing at 45 mg/kg body weight (bw)/day for 2 years, with no effects seen at 9mg/kg bw/day. ° It was not carcinogenic in lifetime skin painting smdies in mice. Ethylenediamine was not genotoxic in a variety of in vivo and in vitro tests.  

No reproductive toxicity was found in rats exposed to 0.50g/kg/day for two generations. A reduction in body weight gain and changes in liver and kidney weights were observed in the Eo and Ei parent rats. A microscopic liver lesion occurred in the Fi rats, with a greater prevalence and severity in the females. In developmental toxicity studies signs of fetotox-icity and developmental delays occurred only at maternally toxic doses. 

In the eye of a rabbit, the liquid caused extreme irritation and corneal damage partial corneal opacity was produced by a 5% solution. The undiluted liquid applied to the shaved skin of rabbits and left uncovered produced severe irritation and necrosis.  

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Bromine is used in the manufacture of many important organic compounds including 1,2-dibromoethane (ethylene dibromide), added to petrol to prevent lead deposition which occurs by decomposition of the anti-knock —lead tetraethyl bromomethane (methyl bromide), a fumigating agent, and several compounds used to reduce flammability of polyester plastics and epoxide resins. Silver(I) bromide is used extensively in the photographic industry... 

B) FROM i,2-DIBROI IOETH. NE. Required Powdered potassium hydroxide, 25 g. rectified spirit, 100 ml. ethylene dibromide, 15 ml. (33 g.). 

Repeat the boiling point determination with the following pure liquids (a) carbon tetrachloride, A.R. (77°) (6) ethylene dibromide (132°) or chlorobenzene (132°) (c) aniline, A.R. (184-6°) and (d) nitrobenzene, A.R. (211°). An air condenser should be used for (c) and (d). Correct the observed boiling points for any appreciable deviation from the normal pressure of 760 mm. Compare the observed boiling points with the values given in parentheses and construct a calibration curve for the thermometer. Compare the latter with the curve obtained from melting point determinations (Section 111,1). 

There are no liquid alkynes whieh can be conveniently prepared by the elementary student. Some of the properties of aeetylenie hydrocarbons may be studied with the gas, aeetylene. Although the latter may be prepared in moderate 3deld by the addition of ethylene dibromide to a boiling aleoholic solution of potassium hydroxide or of sodium ethoxide,... 

The derivatives of ethylene dibromide, propylene dibromide, trimethylene dibromide and tao-butylene dibromide melt at 260°, 232°, 229° and 223° respectively. 

Polyhydric alcohols are compounds containing two or more hydroxyl groups in the molecule. The two most important are ethylene glycol HOCHjCHjOH (a dihydric alcohol) and glycerol HOCHjCH(OH)CH. OH (a trihydric alcohol). Ethylene glycol may be obtained by the hydrolysis of ethylene dibromide or ethylene dichloride with dilute aqueous sodium hydroxide or sodium carbonate solution ... 

The procedure (with ethylene dibromide replacing trimethyleiie dibromide) described for cycZobutanecarboxylic acid (previous Section) does not give satisfactory results when applied to the cyclopropane analogue the yield of the cyclopropane-1 1 dicarboxylic acid is considerably lower and, furthermore, the decarboxylation of the latter gives a considerable proportion (about 30 per cent.) of butyrolactone ... 

Much of the bromine output in the U.S. was used in the production of ethylene dibromide, a lead scavenger used in making gasoline antiknock compounds. Lead in gasoline, however, has been drastically reduced, due to environmental considerations. This will greatly affect future production of bromine. 

Until It was banned in the United States in 1984 1 2 di bromoethane (ethylene dibromide orEDB)waspro duced on a large scale for use as a pesticide and soil fumigant... 

Vinyl Bromide. Vinyl bromide [593-60-2] is prepared by the base-promoted dehydrobromination of ethylene dibromide [106-93 ]. It is used as a comonomer in the production of acrylic fibers. 

Quantitative Analysis of All llithium Initiator Solutions. Solutions of alkyUithium compounds frequentiy show turbidity associated with the formation of lithium alkoxides by oxidation reactions or lithium hydroxide by reaction with moisture. Although these species contribute to the total basicity of the solution as determined by simple acid titration, they do not react with allyhc and henzylic chlorides or ethylene dibromide rapidly in ether solvents. This difference is the basis for the double titration method of determining the amount of active carbon-bound lithium reagent in a given sample (55,56). Thus the amount of carbon-bound lithium is calculated from the difference between the total amount of base determined by acid titration and the amount of base remaining after the solution reacts with either benzyl chloride, allyl chloride, or ethylene dibromide. 

The various fumigants often exhibit considerable specificity toward insect pests, as shown in Table 8. The proper choice for any control operation is determined not only by the effectiveness of the gas but by cost safety to humans, animals, and plants flammabdity penetratabdity effect on seed germination and reactivity with furnishings. The fumigants may be used individually or in combination. Carbon tetrachloride has been incorporated with carbon disulfide, ethylene dichloride, or ethylene dibromide to decrease flammability, and carbon dioxide is used with ethylene oxide for the same purpose. 

In the manufacture of ethylene dibromide, gaseous ethylene is brought into contact with bromine by various methods, allowing for dissipation of the heat of reaction (100—102). Eree acids are neutralized and the product maybe fractionally distilled for purification. Typical specifications call for a clear Hquid with 99.5% purity min sp gr (25/25°C), 2.170—2.180 boiling range, 130.4—132.4°C APHA color, 200 max water, 200 ppm max acidity as HCl, 0.0004 wt % max and nonvolatile matter, 0.0050 wt % max. 

Ethylene dibromide is a suspected human carcinogen and worker exposure by all routes should be carefiiUy controUed to levels as low as reasonably achievable (67). Ethylene dibromide causes severe blistering of the skin if contact is prolonged. Eye contact with the Hquid will cause pain, irritation, and temporary impairment of vision. Recommended safety equipment includes safety goggles, a NIOSH approved canister-type gas mask for organic vapors, neoprene gloves, and neoprene overshoes. In case of contact with ethylene dibromide, contaminated clothing and shoes should be removed and eyes or skin washed with plenty of water for at least 15 minutes. Contaminated clothes should be washed before reuse and contaminated shoes should be discarded. 

About 10% is marketed ia elemental form. Eighteen percent is converted to ethylene dibromide [106-93 ] for use ia gasoline and 30% is used ia fire retardants. Fifteen percent is used as a soil fumigant methyl bromide [74-83-9]. Other commercial forms are alkaU metal bromides, ammonium bromide [12124-97-9] and hydrobromic acid [10035-10-6],... 

Addition. Addition reactions of ethylene have considerable importance and lead to the production of ethylene dichloride, ethylene dibromide, and ethyl chloride by halogenation—hydrohalogenation ethylbenzene, ethyltoluene, and aluminum alkyls by alkylation a-olefms by oligomerization ethanol by hydration and propionaldehyde by hydroformylation. 

The mechanism of poisoning automobile exhaust catalysts has been identified (71). Upon combustion in the cylinder tetraethyllead (TEL) produces lead oxide which would accumulate in the combustion chamber except that ethylene dibromide [106-93-4] or other similar haUde compounds were added to the gasoline along with TEL to form volatile lead haUde compounds. Thus lead deposits in the cylinder and on the spark plugs are minimized. Volatile lead hahdes (bromides or chlorides) would then exit the combustion chamber, and such volatile compounds would diffuse to catalyst surfaces by the same mechanisms as do carbon monoxide compounds. When adsorbed on the precious metal catalyst site, lead haUde renders the catalytic site inactive. 

Caution tevt-Butyllithium ie pyvophovia in air exaeee quantities of the reagent in the syringe should be discarded oery carefully- The checkers used the reagent available from Aldrich Chemical Company Ltd., England and standardized it by double titration with ethylene dibromide and hydrochloric acid. ... 

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