3-(ジクロロメチル)-4-クロロ-5(2H)-フラノン

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational exposure or environmental contamination. Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in soil or water; effects on animal, aquatic, and plant life; and conformance with environmental and public health regulations.

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 59(SRC), determined from a structure estimation method(2), indicates that 3-chloro-4-(dichloromethyl)-2-(5H)-furanone is expected to have high mobility in soil(SRC). Volatilization of 3-chloro-4-(dichloromethyl)-2-(5H)-furanone from moist soil surfaces is expected to be an important fate process(SRC) given an estimated Henry's Law constant of 6.7X10-6 atm-cu m/mole(SRC), using a fragment constant estimation method(3). 3-Chloro-4-(dichloromethyl)-2-(5H)-furanone is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 2.3X10-3 mm Hg(SRC), determined from a fragment constant method(4). Biodegradation data were not available(SRC, 2008).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 59(SRC), determined from a structure estimation method(2), indicates that 3-chloro-4-(dichloromethyl)-2-(5H)-furanone is not expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(3) based upon an estimated Henry's Law constant of 6.7X10-6 atm-cu m/mole(SRC), developed using a fragment constant estimation method(4). Using this Henry's Law constant and an estimation method(3), volatilization half-lives for a model river and model lake are 7.9 days and 62 days, respectively(SRC). According to a classification scheme(5), an estimated BCF of 3.2(SRC), from an estimated log Kow of 0.95(6) and a regression-derived equation(7), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Biodegradation data were not available(SRC, 2008).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), 3-chloro-4-(dichloromethyl)-2-(5H)-furanone, which has an estimated vapor pressure of 2.3X10-4 mm Hg at 25 °C(SRC), determined from a fragment constant method(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase 3-chloro-4-(dichloromethyl)-2-(5H)-furanone is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC); the half-life for this reaction in air is estimated to be 2.2 days(SRC), calculated from its rate constant of 7.4X10-12 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). 3-Chloro-4-(dichloromethyl)-2-(5H)-furanone contains chromophores that absorb at wavelengths >290 nm(4) and therefore may be susceptible to direct photolysis by sunlight(SRC).

During a survey of 12 U.S. water treatment plants conducted between 2000-2002, the highest level of halogenated furanones (as a sum) occurred at a plant that disinfected water containing 11.3 mg/L of TOC and 0.27 mg/L of bromide with chlorine-chloramines (2380 ng/L in plant effluent drinking water) and at a plant that disinfected water containing 3.5 mg/L of TOC and 0.21 mg/L of bromide with chlorine dioxide-chlorine-chloramines (1000 ng/L in the distribution system). The authors noted that an effort was made to selects plants that treat water with high TOC and/or bromide to enable detection of priority disinfection byproducts. The median concentration of halogenated furanones (as a sum, measured in plant effluent) was 310 ng/L, with a 75th percentile concentration of 610 ng/L and a maximum concentration of 2,380 ng/L(1). /Halogenated furnanones/

3-Chloro-4-dichloromethyl)-2(5H)-furanone concentrations in six pairs of US drinking water plants from different geographical regions as defined by the EPA(1). [Table#7322]

Using a structure estimation method based on molecular connectivity indices(1), the Koc of 3-chloro-4-(dichloromethyl)-2-(5H)-furanone can be estimated to be 59(SRC). According to a classification scheme(2), this estimated Koc value suggests that 3-chloro-4-(dichloromethyl)-2-(5H)-furanone is expected to have high mobility in soil.

3-Chloro-4-(dichloromethyl)-2-(5H)-furanone's formation in water as a result of chlorine-treatment processes(1) may result in its release to the environment through various waste streams(SRC). Disinfection byproducts are formed when chlorine or other disinfectants, which are used to control contaminants in drinking water, react with naturally occurring organic and inorganic matter present in water(2).

An estimated BCF of 3.2 was calculated in fish for 3-chloro-4-(dichloromethyl)-2-(5H)-furanone(SRC), using an estimated log Kow of 0.95(1) and a regression-derived equation(2). According to a classification scheme(3), this BCF suggests the potential for bioconcentration in aquatic organisms is low(SRC).

The Henry's Law constant for 3-chloro-4-(dichloromethyl)-2-(5H)-furanone is estimated as 6.7X10-6 atm-cu m/mole(SRC) using a fragment constant estimation method(1). This Henry's Law constant indicates that 3-chloro-4-(dichloromethyl)-2-(5H)-furanone is expected to volatilize from water surfaces(2). Based on this Henry's Law constant, the volatilization half-life from a model river (1 m deep, flowing 1 m/sec, wind velocity of 3 m/sec)(2) is estimated as 7.9 days(SRC). The volatilization half-life from a model lake (1 m deep, flowing 0.05 m/sec, wind velocity of 0.5 m/sec)(2) is estimated as 62 days(SRC). 3-Chloro-4-(dichloromethyl)-2-(5H)-furanone's Henry's Law constant indicates that volatilization from moist soil surfaces may occur(SRC). 3-Chloro-4-(dichloromethyl)-2-(5H)-furanone is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 2.3X10-3 mm Hg(SRC), determined from a fragment constant method(3).

/GENOTOXICITY/ The mutagenic activities of the chlorinated butenoic acids recently identified in chlorinated drinking waters were determined by the Salmonella microsome assay and by the SOS chromotest. The Salmonella typhimurium tester strains TA97, TA98 and TA100 were used without and with S9 mix. In the SOS chromotest Escherichia coli PQ37 was used as an indicator organism with and without metabolic activation. In addition, the extremely potent Ames test mutagen (Z)-2-chloro-3-(dichloromethyl)-4-oxobutenoic acid (MX, in the open form), was studied by the micronucleus test with mice using intraperitoneal treatment. The results of the Salmonella assay and the SOS chromotest showed that MX was by far the most potent mutagen of the compounds tested. Mutations were also induced by the reduced form of MX, (Z)-2-chloro-3-(dichloromethyl)-4-hydroxybut-2-enoic acid (red-MX), and by the geometric isomer of MX, (E)-2-chloro-3-(dichloromethyl)-4-oxobutenoic acid (EMX). However, since the solution of EMX contained approximately 5% MX, most of its activity might be attributable to MX. The oxidised form of EMX, (E)-2-chloro-3-(dichloromethyl)-butenedioic acid (ox-EMX), was marginally active in the SOS chromotest only. All these compounds were directly acting mutagens and in the presence of metabolic activation (S9 mix) they did not generate mutagenicity. The oxidized form of MX, (Z)-2-chloro-3-(dichloromethyl)-butenedioic acid (ox-MX), was not mutagenic at the dose levels tested. MX did not induce micronuclei in the bone marrow of mice.

/GENOTOXICITY/ The strong Ames mutagen 3-chloro-4-(dichloromethyl)-5-hydroxy-2 (5H)-furanone (MX) and its geometric isomer E-2-chloro-3-(dichloromethyl)-4-oxobutenoic acid (E-MX) have been shown to be present in chlorinated drinking waters. MX accounts for approximately 30% and E-MX for a few percent of the overall mutagenicity. MX and E-MX are unstable in water and undergo both pH dependent isomerization (MX in equilibrium E-MX) and hydrolytic degradation. ... The MX analogues 3-chloro-4-(dichloromethyl)-2 (5H)-furanone (red-MX) and 2-chloro-3-(dichloromethyl)-2-butenedioic acid (ox-MX) have also been identified in chlorinated water. However, the relatively low mutagenicity of these compounds suggests that their contribution to the overall mutagenicity of chlorinated water is of only moderate significance.

/GENOTOXICITY/ The mutagenicities of 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX, compound 1), 3-chloro-4-(dichloromethyl)-2(5H)-furanone (RMX, compound 6), and 2-(dichloromethyl)-3,3-dichloropropenal (TCB, compound 7) were determined in the same assay and in repetitive determinations using Salmonella typhimurium (TA100) without microsomal fraction activation. In addition, the mutagenicity of 2-methyl-3,3-dichloropropenal (compound 8) was assayed in the same manner although not simultaneously with MX, RMX, and TCB. This study was undertaken to ascertain the role of open- and closed-ring forms of MX in the mutagenicity of MX. MX proved to be roughly 100 times more mutagenic than the open-ring analogue TCB and 10 times more mutagenic than the closed-ring analogue RMX. Compound 8 was inactive. ... The enhanced mutagenicity of MX relative to RMX and TCB is attributed to the intrinsic mutagenicity of MX and its greater stability is judged to play only a minor role. Moreover, the greater mutagenicity of the closed-ring analogue RMX relative to the open-ring analogue TCB points to the ring form of MX as the active species even though the open form of MX is predominant under assay conditions.

The rate constant for the vapor-phase reaction of 3-chloro-4-(dichloromethyl)-2-(5H)-furanone with photochemically-produced hydroxyl radicals has been estimated as 7.4X10-12 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 2.2 days at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). The rate constant for the vapor-phase reaction of 3-chloro-4-(dichloromethyl)-2-(5H)-furanone with ozone has been estimated as 1.1X10-17 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(1). This corresponds to an atmospheric half-life of about 1.1 days at an atmospheric concentration of 7X10+11 ozone molecules per cu cm(2). 3-Chloro-4-(dichloromethyl)-2-(5H)-furanone is expected to undergo hydrolysis in the environment due to the presence of functional groups that hydrolyze under environmental conditions(3). 3-Chloro-4-(dichloromethyl)-2-(5H)-furanone contains chromophores that absorb at wavelengths >290 nm(3) and therefore may be susceptible to direct photolysis by sunlight(SRC).

3-Chloro-4-(dichloromethyl)-2-(5H)-furanone's formation in water as a result of chlorine-treatment processes may result in its release to the environment through various waste streams. Disinfection byproducts are formed when chlorine or other disinfectants, which are used to control contaminants in drinking water, react with naturally occurring organic and inorganic matter present in water. If released to air, an estimated vapor pressure of 2.3X10-3 mm Hg at 25 °C indicates 3-chloro-4-(dichloromethyl)-2-(5H)-furanone will exist solely as a vapor in the atmosphere. Vapor-phase 3-chloro-4-(dichloromethyl)-2-(5H)-furanone will be degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals; the half-life for this reaction in air is estimated to be 2.2 days. 3-Chloro-4-(dichloromethyl)-2-(5H)-furanone contains chromophores that absorb at wavelengths >290 nm and therefore may be susceptible to direct photolysis by sunlight. If released to soil, 3-chloro-4-(dichloromethyl)-2-(5H)-furanone is expected to have high mobility based upon an estimated Koc of 59. Volatilization from moist soil surfaces is expected to be an important fate process based upon an estimated Henry's Law constant of 6.7X10-6 atm-cu m/mole. Biodegradation data were not available. If released into water, 3-chloro-4-(dichloromethyl)-2-(5H)-furanone is not expected to adsorb to suspended solids and sediment based upon the estimated Koc. Volatilization from water surfaces is expected to be an important fate process based upon this compound's estimated Henry's Law constant. Estimated volatilization half-lives for a model river and model lake are 7.9 days and 62 days, respectively. An estimated BCF of 3.2 suggests the potential for bioconcentration in aquatic organisms is low. Hydrolysis is expected to be an important environmental fate process since this compound contains functional groups that hydrolyze under environmental conditions. The most likely pathway by which the general public is exposed to this compound is by ingestion of and dermal contact with chlorinated drinking water and effluent. (SRC)