1,2-Dibromo-3-chloropropane

Production Methods

DBCP is produced by liquid phase addition of bromine to allyl chloride. It was first produced commercially in the United States in 1955.

Air & Water Reactions

Flammable. Soluble in water. Hydrolyzed in alkali.

Reactivity Profile

1,2-Dibromo-3-chloropropane reacts with chemically active metals such as aluminum, magnesium, tin and their alloys. 1,2-Dibromo-3-chloropropane will attack some rubber materials and coatings.

Trade name

BBC 12?; FUMAGONE?; FUMAZONE?[C]; MEMATOCIDE?; NEMABROM?; NEMAFUM?; NEMAGON?[C]; NEMAGON SOIL FUMIGANT?[C]; NEMANAX?; NEMAPAZ?; NEMASET?; NEMATOCIDE?[C]; NEMATOX?; NEMAZON?; OS 1897?; OXY BCP?[C]; SD 1897?

Safety Profile

Confirmed human carcinogen with experimental carcinogenic and teratogenic data. Poison by ingestion, inhalation, and subcutaneous routes. Moderately toxic by skin contact. An eye and severe skin irritant. Narcotic in high concentrations. Has been implicated in causing human sterihty in male factory workers. Human mutation data reported. A soil fumigant. Combustible. When heated to decomposition it emits toxic fumes of Cl and Br-. See also CHLORIDES and BROLVIDES.

Carcinogenicity

1,2-Dibromo-3-chloropropane is reasonably anticipated to be a human carcinogen based on sufficient evidence of carcinogenicity fromstudies in experimental animals.

Environmental Fate

Biological. Biodegradation is not expected to be significant in removing 1,2-dibromo- 3-chloropropane. In aerobic soil columns, no degradation was observed after 25 days (Wilson et al., 1981a). Soil. Soil water cultures converted 1,2-dibromo-3-chloropropane to n-propanol, bromide and chloride ions. Precursors to the alcohol formation include allyl chloride and allyl alcohol (Castro and Belser, 1968). The reported half-life in soil is 6 months (Jury et al., 1987). Groundwater. According to the U.S. EPA (1986) 1,2-dibromo-3-chloropropane has a high potential to leach to groundwater. Chemical/Physical. 1,2-Dibromo-3-chloropropane is subject to both neutral and basemediate hydrolysis (Kollig, 1993). Under neutral conditions, the chlorine or bromine atoms may be displaced by hydroxyl ions. If nucleophilic attack occurs at the carbon-chlorine bond, 2,3-dibromopropanol is formed which reacts further to give 2,3-dihydroxybromopropane via the intermediate epibromohydrin. 2,3-Dihydroxybromopropane will undergo hydrolysis via the intermediate 1-hydroxy-2,3-propylene oxide which further reacts with water to give glycerol. If the nucleophilic attack occurs at the carbon-bromine bond, 2- bromo-3-chloropropanol is formed which further reacts forming the end product glycerol (Kollig, 1993). If hydrolysis of 1,2-dibromo-2-chloropropane occurs under basic conditions, the compound will undergo dehydrohalogenation to form 2-bromo-3-chloropropene and 2,3-dibromo-1-propene as intermediates. Both compounds are subject to further attack forming 2-bromo-3-hydroxypropene as the end product (Burlinson et al., 1982; Kollig, 1993). The hydrolysis half-life at pH 7 and 25°C was calculated to be 38 years (Burlinson et al., 1982; Ellington et al., 1986). Emits toxic chloride and bromide fumes when heated to decomposition (Lewis, 1990).

Toxicity evaluation

DBCP in soil can volatilize from near-surface soil. Based on estimated Koc values of 149 in Lincoln fine sand and 128 in an unspecified soil, DBCP will be highly mobile in soil and has the capacity to leach into groundwater. It is estimated that the volatilization half-life for this chemical will vary between 0.6 days in dry soil with low soil organic content and 26.2 days in a wet soil containing high values of soil organic content. It is important to notice that fields treated with DBCP will present a significant retardation in the volatilization loss from the soil if plastic coverings are used.DBCP will exist primarily in the vapor phase in the ambient atmosphere. It is expected that very small amounts of this chemical will be present in the particulate phase, and this could explain the fact that dry deposition to the earth’s surface will not result in a significant removal process. DBCP presents high water solubility, and then small amounts present in the air can be removed by wet deposition.If found in water, DBCP will volatilize quite rapidly to the atmosphere; the estimated volatilization half-life from a pond is 8 days. Using again the estimated Koc values of 128–149, this chemical is not expected to adsorb significantly to sediment and suspended organic matter. Based on an estimated bioconcentration factor (BCF) of 11.2, it is not expected to bioconcentrate in fish and other aquatic organisms. There is no sufficient data to indicate that DBCP could be a potential risk in terms of biomagnifications in different aquatic or terrestrial food chains. However, some biodegradation of DBCP in groundwater might ensue under anaerobic conditions.

Physical properties

Colorless when pure, however, technical grades are yellowish to dark brown. Pungent odor at high concentrations

General Description

A colorless liquid. Denser than water. Flash point 170°F. Boiling point 195°F. Toxic by ingestion and inhalation. Used as a pesticide and fumigant.

Agricultural Uses

Nematicide, Fumigant: DBCP has been used in agriculture as a nematicide since 1955, being supplied for such use in the forms of liquid concentrate, emulsifiable concentrate, powder, granules, and solid material. A rebuttable presumption against registration for pesticide uses was issued by U.S. EPA on September 22, 1977, on the basis of oncogenicity and reproductive effects. Then, as of November 3, 1977, EPA in a further action suspended all registrations of end-use products, subject to various specific restrictions. Not listed as registered in EU countries.