Benzothiazole

SRP: At the time of review, criteria for land treatment or burial (sanitary landfill) disposal practices are subject to significant revision. Prior to implementing land disposal of waste residue (including waste sludge), consult with environmental regulatory agencies for guidance on acceptable disposal practices.

1.1 [mg/m3]

13 [mg/m3]

75 [mg/m3]

TERRESTRIAL FATE: Based on a recommended classification scheme(1), an estimated Koc value of 295(SRC), determined from an experimental log Kow(2,SRC) and a recommended regression-derived equation(3), indicates that benzothiazole will have moderate mobility in soil(SRC). Volatilization of benzothiazole will not be important from moist soil surfaces(SRC) given an estimated Henry's Law constant of 3.7X10-7 atm-cu m/mole(SRC), using a fragment constant estimation method(4). Biodegradation of benzothiazole occurs rapidly under aerobic conditions. Employing a standard BOD dilution technique and an activated sludge inoculum, a theoretical BOD of 100% was observed for a 0.0125 mM sample of benzothiazole over an unspecified time period(5). Unspecified concentrations of benzothiazole were degraded by both mixed cultures and activated sludge mediums(6).

AQUATIC FATE: Based on a recommended classification scheme(1), an estimated Koc value of 295(SRC), determined from an experimental log Kow(2,SRC) and a recommended regression-derived equation(1), indicates that benzothiazole may adsorb to suspended solids and sediment in water(SRC). Volatilization from water surfaces should be slow based upon an estimated Henry's law constant of 3.7X10-7 atm-cu m/mol (SRC), developed using a fragment constant estimation method(3). Estimated half-lives for a model river and model lake are 114 and 832 days, respectively(1,SRC). According to a classification scheme(4), an estimated BCF value of 20(1,SRC), from an experimental log Kow(2), suggests that bioconcentration in aquatic organisms is low(SRC). The biodegradation of benzothiazole occurs rapidly under aerobic conditions. Complete biodegradation of 72X10-6 mols/l of benzothiazole incorporated into an activated sludge medium obtained from a municipal wastewater treatment facility was observed after a period of 16 days(5).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), benzothiazole, which has an estimated vapor pressure of 0.014 mm Hg at 25 °C(2,SRC), will exist solely as a vapor in the ambient atmosphere. Benzothiazole 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 about 18 hours(3,SRC).

Quantities of benzothiazole were found in salt fermented anchovies and hair tail viscera shrimp at concentrations of 124 ng/g and 247 ng/g respectively(1). Unspecified amounts of benzothiazole were detected in samples of cassava roots from the Dominican Republic(2), nectarines from California(3), apples from Kogyoku, Japan(4) and volatiles of roasted filbert nuts(5).

ONE OF 2 TIRE PLANTS STUDIED FOR TRACE ORGANIC COMPDS IN WASTE WATERS RECYCLES ANTI-TACK SOLN & EMITS MOSTLY BENZOTHIAZOLE & 2-MERCAPTOBENZOTHIAZOLE.

Benzothiazole was detected in effluents of German incinerator plants at concentrations of about 3.1X10-7 g/cu m (1). Unspecified concentrations of benzothiazole were detected in pyrolytic oil waste streams in Winchester, Virginia following a fire at a tire storage facility(2). Unspecified concentrations of benzothiazole were detected in effluents from rubber vulcanization manufacturing facilities(3,4). Concentrations of 2 ppb were detected in wastewater streams in the vicinity of a specialty chemical manufacturing plant whose location was not specified(5). Benzothiazole was detected in tire manufacturing plant wastewater streams at unspecified locations at concentrations of 20-60 ppb(6).

The Koc of benzothiazole is estimated as approximately 295(SRC), using an experimental log Kow of 2.01(1,SRC) and a regression-derived equation(2,SRC). According to a recommended classification scheme(3), this estimated Koc value suggests that benzothiazole has moderate mobility in soil(SRC).

Benzothiazole's production and use as a synthetic reagent in organic chemistry(1) may result in its release to the environment through various waste streams(SRC). The degradation of fungicides containing 2-(thiocyanomethylthio)benzothiazole and the rubber vulcanization agent, 2-mercaptobenzothiazole results in the formation of benzothiazole(2).

Complete biodegradation of 72X10-6 mols/l of benzothiazole incorporated into an activated sludge medium obtained from a municipal wastewater treatment facility was observed after 16 days (1). Employing a standard BOD dilution technique and an activated sludge inoculum, a theoretical BOD of 100% was observed for a 0.0125 mM sample of benzothiazole over an unspecified time period, while a 0.125 mM sample produced a theoretical BOD of 10%(2). An activated sludge innoculum biodegraded benzothiozaole over a 6 month incubation period(3). This data would suggest that low levels of benzothiazole are totally biodegraded, while high concentrations are expected to be toxic to microbes(SRC).

An estimated BCF value of 20 was calculated for benzothiazole(SRC), using an experimental log Kow of 2.01(1) and a recommended regression-derived equation(2). According to a classification scheme(3), this BCF value suggests that bioconcentration in aquatic organisms is low(SRC).