テトラデシルベンゼン

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 1.7X10+6(SRC), determined from a structure estimation method(2), indicates that tetradecylbenzene is expected to be immobile in soil(SRC). Microbial metabolism is expected to be the primary degradation process for linear alkyl benzenes(LAB) in nature(3). LAB undergoes rapid primary biodegradation in natural waters and the same is expected to occur in soil environments(3). Volatilization of tetradecylbenzene from moist soil surfaces is expected to be an important fate process(SRC) given an estimated Henry's Law constant of 0.237 atm-cu m/mole(SRC), using a fragment constant estimation method(4). However, adsorption to soil is expected to attenuate volatilization(SRC). Tetradecylbenzene is not expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 2.38X10-5 mm Hg(5).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 1.7X10+6(SRC), determined from a structure estimation method(2), indicates that tetradecylbenzene is expected to adsorb to suspended solids and sediment in water(SRC). Volatilization from water surfaces is expected(3) based upon an estimated Henry's Law constant of 0.237 atm-cu m/mole(SRC), developed using a fragment constant estimation method(3). Volatilization half-lives for a model river and model lake are 5 and 160 hrs, respectively(SRC), using an estimation method(2). However, the volatilization half-life does not take into account the effects of adsorption. An estimated Koc of 1.7X10+6 suggests that volatilization could be attenuated by adsorption to suspended solids and sediments in water(SRC). This is apparent from the results of two EXAMS model runs, one in which the effect of adsorption was considered, yielding an estimated half-life of 17.7 yrs in a model pond 2 m deep, and one in which the effect of adsorption was ignored, yielding an estimated half-life of 6hrs in a model pond 2 m deep(4). River die-away tests have shown that linear alkyl benzenes (LAB) are readily biodegradable with half-lives ranging from 4.3 to 11.4 days(5). According to a classification scheme(6), an estimated BCF of 4.71(SRC), from an estimated log Kow of 8.92(7) and a regression-derived equation(8), suggests the potential for bioconcentration in aquatic organisms is low.

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), tetradecylbenzene, which has a vapor pressure of 2.38X10-5 mm Hg at 25 °C(2), is expected to exist in both the vapor and particulate phases in the ambient atmosphere. Vapor-phase tetradecylbenzene 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 16.8 hrs(SRC), calculated from its estimated rate constant of 2.29X10-11 cu cm/molecule-sec at 25 °C(SRC) determined using a structure estimation method(3). Particulate-phase tetradecylbenzene may be removed from the air by wet and dry deposition(SRC).

In California, concns of linear alkyl benzenes (LAB) ranging from 25 to 2,200 ug/l and 78 to 302 ug/l in final sewage effluents and from 1 to 34 mg/l in marine sediments near sewage outfalls were reported(1). Investigators attribute LAB concns in wastewaters and the environment to residual unsulfonated LAB in linear alkylsulfonate (LAS) detergents(1).

The Koc of tetradecylbenzene is estimated as 1.7X10+6(SRC), using an estimated log Kow of 8.92(1,SRC) and a regression-derived equation(2). According to a classification scheme(3), this estimated Koc value suggests that tetradecylbenzene is expected to be immobile in soil.

Tetradecylbenzene's production and use as in linear alkyl sulfonate detergents(1) may result in its release to the environment through various waste streams. The vast majority of manufactured linear alkylbenzes (LAB) are converted to linear alkyl sulfonate (LAS) detergents which may contain 1 to 3% residual unsulfonated LAB(1). Tetradecylbenzene may also be released to the environment through shoe-sole factory processes(2).

River die-away tests have shown that linear alkyl benzenes (LAB) (C10 to C13 alkyl chain length) are readily biodegradable with half-lives ranging from 4.3 to 11.4 days(1). The LAB compounds with longer alkyl chains degraded faster than shorter ones(1). Due to tetradecylbenzene's similar structure (C14 alkyl chain length), it is expected to readily biodegrade in the environment(SRC).

An estimated BCF of 4.71 was calculated for tetradecylbenzene(SRC), using an estimated log Kow of 8.92(1,SRC) and a regression-derived equation(2). According to a classification scheme(3), this BCF suggests the potential for bioconcentration in aquatic organisms is low. The BCF for linear alkylbenzenes (LAB) was studied for bluegill fish(4). A BCF value of 35 was determined from the mean exposure concn of 0.092 mg/l and the steady state whole fish residue concn of 2.3 ug/g(4). This low value is suspected to be due mainly to metabolism(4).

The Henry's Law constant for tetradecylbenzene is estimated as 0.237 atm-cu m/mole(SRC) using a fragment constant estimation method(1). This Henry's Law constant indicates that tetradecylbenzene is expected to volatilize rapidly 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 5 hrs(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 160 hrs(SRC). Tetradecylbenzene's Henry's Law constant(1) indicates that volatilization from moist soil surfaces may occur(SRC). However, the volatilization half-life does not take into account the effects of adsorption. An estimated Koc of 1.7X10+6(SRC), from an estimated log Kow of 8.92(3) and a regression-derived equation(4), suggests that volatilization could be attenuated by adsorption to suspended solids and sediments in water(SRC). This is apparent from the results of two EXAMS model runs, one in which the effect of adsorption was considered, yielding an estimated half-life of 17.7 yrs in a model pond 2 m deep, and one in which the effect of adsorption was ignored, yielding an estimated half-life of 62 hrs in a model pond 2 m deep(5). Tetradecylbenzene is not expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 2.38X10-5 mm Hg(6).

The rate constant for the vapor-phase reaction of tetradecylbenzene with photochemically-produced hydroxyl radicals has been estimated as 2.29X10-11 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 16.8 hrs at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). Tetradecylbenzene is not expected to undergo hydrolysis in the environment due to the lack of hydrolyzable functional groups(2) nor to directly photolyze due to the lack of absorption in the environmental UV spectrum.

Occupational exposure to tetradecylbenzene may occur through inhalation and dermal contact with this compound at workplaces where linear alkylsulfonate (LAS) detergents(1) and shoe-soles are produced(2). The general population may be exposed to tetradecylbenzene via ingestion of drinking water(1) and dermal contact with this compound and detergents containing tetradecylbenzene.

Tetradecylbenzene production and use in linear alkylsulfonate (LAS) detergents may result in its release to the environment through various waste streams. If released to air, a vapor pressure of 2.38X10-5 mm Hg at 25 °C indicates tetradecylbenzene will exist in both the vapor and particulate phases in the ambient atmosphere. Vapor-phase tetradecylbenzene 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 16.8 hrs. Particulate-phase tetradecylbenzene will be removed from the atmosphere by wet and dry deposition. If released to soil, tetradecylbenzene is expected to be immobile based upon an estimated Koc of 1.6X10+6. Volatilization from moist soil surfaces is expected to be an important fate process based upon an estimated Henry's Law constant of 0.237 atm-cu m/mole. However, adsorption to soil is expected to attenuate volatilization. Tetradecylbenzene is not expected to volatilize from dry soil surfaces based upon its vapor pressure. If released into water, tetradecylbenzene is expected to adsorb to suspended solids and sediment based upon the estimated Koc. River die-away tests have shown that linear alkyl benzenes(LAB) are readily biodegradable with half-lives ranging from 4.3 to 11.4 days. 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 5 and 160 hrs, respectively. However, volatilization from water surfaces is expected to be attenuated by adsorption to suspended solids and sediment. An estimated BCF of 4.71 suggests the potential for bioconcentration in aquatic organisms is low. Hydrolysis is not expected to occur due to the lack of hydrolyzable functional groups. Occupational exposure to tetradecylbenzene may occur through inhalation and dermal contact with this compound at workplaces where LAS detergents and shoe-soles are produced. The general population may be exposed to tetradecylbenzene via ingestion of drinking water and dermal contact with this compound and LAS detergents containing tetradecylbenzene. (SRC)