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The information in this profile may be out-of-date. It was last revised in 1996. EXTOXNET no longer updates this information, but it may be useful as a reference or resource.

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E X T O X N E T

Extension Toxicology Network

Pesticide Information Profiles

A Pesticide Information Project of Cooperative Extension Offices of Cornell University, Oregon State University, the University of Idaho, and the University of California at Davis and the Institute for Environmental Toxicology, Michigan State University. Major support and funding was provided by the USDA/Extension Service/National Agricultural Pesticide Impact Assessment Program.

EXTOXNET primary files maintained and archived at Oregon State University

Revised June 1996

Ethylene dibromide (EDB), dibromoethane

Trade and Other Names: The chemical name for EDB is 1,2-dibromoethane, and synonyms include DBE; alpha, beta-dibromoethane; dibromoethane; ethylene bromide; glycol bromide; glycol dibromide; and sym-dibromoethane. Product names include Bromofume, Celmide, Dibrome, Dowfume, EDB-85, Fumo-Gas, Kopfume, Nephis, and Soilfume.

Regulatory Status: Ethylene dibromide (EDB) is a highly toxic compound in EPA Toxicity Class I. It is not registered for use in the U.S. In 1983, the EPA suspended the use of EDB as a fumigant when low-level residues were found in groundwater and some grains.

Chemical Class: Not Available

Introduction: Ethylene dibromide (EDB) is used extensively as a soil and post-harvest fumigant for crops, and as a quarantine fumigant for citrus and 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.

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

Toxicological Effects:

• Acute toxicity: EDB is highly toxic via ingestion, with reported oral LD50 values of 108 to 146 mg/kg in rats, 250 mg/kg in mice, and 55 mg/kg in rabbits [8]. The lowest fatal oral dose for humans was reportedly 90 mg/kg [8]. The dermal LD50 was unavailable, but EDB can be rapidly absorbed through the skin [8]. EDB is reportedly a severe skin and eye irritant, and can cause skin blistering with contact [8,175]. The reported 2-hour inhalation LC50 is 3 mg/L in rats; the reported 1-hour inhalation LC50 is 5 mg/L, indicating high toxicity. A woman who ingested 4.5 mL of an EDB concentrate experienced rapid breathing, vomiting, and diarrhea prior to expiring [8]. Liver and kidney damage were noted in her post-mortem examination [8]. Administration of very high single oral doses of EDB to rats and chicks caused changes in the livers of these animals within 22 hours [176]. In rats, inhalation of small concentrations of EDB vapors depresses weight gain, and slightly higher levels damage the lungs. Changes in the lungs and respiratory tract and temporary clouding of the corneas have been seen in animal studies after only 1 week of exposure to workplace levels of EDB [8]. Other effects of acute exposure may include headache, depression, and nausea or loss of appetite. Four deaths have been attributed to accidental poisoning by EDB [8].
• Chronic toxicity: Daily inhalation of EDB vapors for 6 to 13 weeks at levels comparable to human occupational exposures damaged the liver, kidney, and testes of rats, and changed chick livers [8].
• Reproductive effects: A study of male workers exposed to low air levels of EDB at four separate manufacturing sites showed no consistent association between EDB and reproductive effects [177]. However, another study of 46 men exposed to a lower average air concentration for 5 years showed adverse effects on sperm number, movement, survival, and structure [8]. Bulls had abnormal sperm after 12 to 21 days of EDB exposure [8]. Fetal deaths increased in offspring of adult male rats given high doses of EDB in the diet for 5 days before mating [8]. Cows and ewes given lower doses did not show any effects on reproduction [8]. The available data indicate that reproductive effects may be possible in humans, but that there may be a (threshold) level below which effects are very unlikely.
• Teratogenic effects: In one study, no teratogenic effects were observed in offspring of pregnant rats and mice who were exposed to various levels of EDB vapors for 23 hours a day during the sensitive period of gestation [178]. At all doses, both rats and mice showed body weight decreases, and a significant number of deaths occurred in the adults exposed to the high doses. Since these effects occurred at doses that caused serious adverse maternal effects, it was unclear whether the observed fetal toxicity was caused simply by reduced maternal health [178]. Hens fed daily diets of 1 to 2 ppm EDB had decreased egg weights [8]. The available evidence suggest that EDB does not cause teratogenic effects.
• Mutagenic effects: EDB has been shown to be weakly mutagenic in several bacterial and animal test systems [8]. It has not been shown to be mutagenic in humans, either in cell cultures or in the whole organism [8].
• Carcinogenic effects: Rats inhaling high daily doses of EDB for 18 months developed tumors of the mammary glands, spleen, adrenals, liver, and kidney [179]. When rats were subjected to airborne EDB and also given disulfiram orally over 14 months, increased tumors in the liver, kidneys, thyroids, and lungs appeared. The tumor increase was higher than that caused by EDB at the same levels over 18 months [179]. The available evidence indicates that EDB may be carcinogenic.
• Organ toxicity: EDB contact may damage the lung, skin, and eyes. Acute and chronic systemic effects may be seen in the liver, kidneys, and heart, and other internal organs and systems. Lung injury can also lead to secondary effects such as pneumonia and respiratory tract infections.

• Fate in humans and animals: EDB is readily and rapidly absorbed across the lung, skin, and gastrointestinal tract in liquid and vapor forms [8]. Once absorbed, it is rapidly broken down, and metabolites may be found in the urine, kidneys, liver, adrenal glands, pancreas, and spleen of EDB-exposed animals shortly after application [8]. About two thirds of the applied dose are excreted through urine or expired air [178]. EDB has a biological half-life of less than 48 hours in rats, chicks, mice, and guinea pigs [8].

Ecological Effects:

• Effects on birds: EDB is most likely to be in vapor form, and unless birds are in the fumigation area, during the fumigation, they are unlikely to be exposed.
• Effects on aquatic organisms: EDB is slightly toxic to fish [8]. The reported LC50 value in the shiner is 40.3 mg/L. The calculated bioconcentration factor for EDB in aquatic organisms ranges between 9.3 to 10.2, suggesting that it has a low potential for bioaccumulation [180].
• Effects on other organisms: No data are currently available.

Environmental Fate:

• Breakdown in soil and groundwater: The fastest degradation of EDB occurs at or near the soil surface. EDB is moderately persistent in the soil environment; a representative field half-life was estimated to be 100 days [11]. In one study, after 2 months, almost all of EDB was dissipated [11,181]. Sunlight readily degrades EDB. EDB near the soil surface is converted to ethylene and bromide ions, and that small percentage which remains is unchanged, possibly adsorbed to soil organic matter or clay particles or entrapped in soil micropores [181]. EDB thus entrapped may be inaccessible to microbial degraders and may slowly leach to groundwater over very long periods [181]. Such leaching is very slow at normal temperatures, but increases with higher temperatures [181]. Groundwater contamination of EDB has been confirmed at levels up to 0.3 mg/L [182,183]. Usual levels of EDB found in groundwater were approximately 0.001 to 0.02 mg/L, which are similar to levels found in stored grain products [182].
• Breakdown in water: EDB can be widely distributed in aqueous systems. The primary removal process for ethylene dibromide in water is evaporation [182]. EDB has a half-life of slightly over 1 day in river water, and about 5 days in lake water [182,184]. Binding to sediment is relatively low. EDB decomposes in the presence of heat and/or light and can be slowly broken down by moisture. The major degradation products in water are also ethylene and bromide ions.
• Breakdown in vegetation: Because of the inability of plants to take EDB up from soil, it is not likely to accumulate in plants. However, EDB's breakdown product, inorganic bromide, is taken up by plants in small amounts. Residues of EDB persist in fumigated food products for 6 to 12 weeks. EDB residues in grain and feed do not accumulate in livestock to any significant extent. Cooking may dramatically reduce the levels of EDB residues in foods [8].

Physical Properties:

• Appearance: Ethylene dibromide is a heavy, colorless liquid with a mildly sweet, chloroform odor [1].
• Chemical Name: 1,2-dibromoethane [53]
• CAS Number: 109-93-4
• Molecular Weight: 187.90
• Water Solubility: 4300 mg/L @ 20 C [53]
• Solubility in Other Solvents: soluble in alcohols, ethers, acetone, benzene, and most organic solvents [8]
• Melting Point: 9.8 C [8]
• Vapor Pressure: 1.5 x 10^6 mPa [53]
• Partition Coefficient: 53.7-61.7 (calculated) [8]
• Adsorption Coefficient: 34 (estimated) [53]

Exposure Guidelines:

• ADI: 1.0 mg inorganic bromide mg/kg/day [12]
• MCL: 0.00005 mg/L [65]
• RfD: Not Available
• PEL: 154 mg/m3 (8-hour)
• HA: Not Available
• TLV: Not Available

Basic Manufacturer:

United Phosphorous Ltd.
Readymoney Terrace
167 Dr. Annie Besant Rd.
Bombay 400 018 India

• Phone: 22-493-0681
• Emergency: 22-493-2427
  

References:

References for the information in this PIP can be found in Reference List Number 10

DISCLAIMER: The information in this profile does not in any way replace or supersede the information on the pesticide product labeling or other regulatory requirements. Please refer to the pesticide product labeling.