1-Tetracosanol

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 5.1X10+5(SRC), determined from a structure estimation method(2), indicates that 1-tetracosanol is expected to be immobile in soil(SRC). Volatilization of 1-tetracosanol from moist soil surfaces is expected to be an important fate process(SRC) given an estimated Henry's Law constant of 2.9X10-3 atm-cu m/mole(SRC), using a fragment constant estimation method(3). However, adsorption to mosit soil is expected to attenuate volatilization(SRC). 1-Tetracosanol is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 2.4X10-9 mm Hg(SRC), determined from a fragment constant method(4). Biodegradation data were not available(SRC, 2006), but long chain linear alcohols are expected to biodegrade(5).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 5.1X10+5(SRC), determined from a structure estimation method(2), indicates that 1-tetracosanol is 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 2.9X10-3 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 6 hours and 7.6 days, respectively(SRC). However, volatilization from water surfaces is expected to be attenuated by adsorption to suspended solids and sediment in the water column. The estimated volatilization half-life from a model pond is 14 years if adsorption is considered(5). According to a classification scheme(6), an estimated BCF of 3(SRC), from an estimated log Kow of 11(7) and a regression-derived equation(8), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Biodegradation data were not available(SRC, 2006), but long chain linear alcohols are expected to biodegrade(8).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), 1-tetracosanol, which has an estimated vapor pressure of 2.4X10-9 mm Hg at 25 °C(SRC), determined from a fragment constant method(2), will exist in both the vapor and particulate phases in the ambient atmosphere. Vapor-phase lignoceryl alcohol 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 11 hours(SRC), calculated from its rate constant of 3.5X10-11 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). Particulate-phase 1-tetracosanol may be removed from the air by wet or dry deposition(SRC).

1-Tetracosanol emission rates from wood smoke were calculated as 2.9 ug/g, 0.7 ug/g, and 2.9 ug/g from oak, eucalyptus and pine, respectively(1). 1-Tetracosanol emission rate from road dust samples was 22 ug/g(2). 1-Tetracosanol emission rate from pine wood (Pinus elliottii) smoke was measured at 1163 ng/g of burnt wood(3). 1-Tetracosanol was identified in smoke from the burning of chitin biopolymers(4).

Using a structure estimation method based on molecular connectivity indices(1), the Koc of 1-tetracosanol can be estimated to be 5.1X10+5(SRC). According to a classification scheme(2), this estimated Koc value suggests that 1-tetracosanol is expected to be immobile in soil.

1-Tetracosanol's production and possible use as a chemical intermediate(1) may result in its release to the environment through various waste streams. It's possible use as a water reservoir evaporation inhibitor(1) would result in its direct release to the environment.

An estimated BCF of 3 was calculated for 1-tetracosanol(SRC), using an estimated log Kow of 10.66(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 1-tetracosanol is estimated as 2.9X10-3 atm-cu m/mole(SRC) using a fragment constant estimation method(1). This Henry's Law constant indicates that 1-tetracosanol 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 6 hours(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 7.6 days(SRC). However, volatilization from water surfaces is expected to be attenuated by adsorption to suspended solids and sediment in the water column. The estimated volatilization half-life from a model pond is 14 years if adsorption is considered(3). 1-Tetracosanol's Henry's Law constant indicates that volatilization from moist soil surfaces may occur(SRC). 1-Tetracosanol is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 2.4X10-9 mm Hg(SRC), determined from a fragment constant method(4).

The rate constant for the vapor-phase reaction of 1-tetracosanol with photochemically-produced hydroxyl radicals has been estimated as 3.5X10-11 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 11 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). 1-Tetracosanol is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(2).

NIOSH (NOES Survey 1981-1983) has statistically estimated that 1281 workers (1064 of these are female) are potentially exposed to 1-tetracosanol in the US(1). Occupational exposure to 1-tetracosanol may occur through dermal contact with products containing this compound(SRC). Monitoring data indicate that the general population may be exposed to 1-tetracosanol via inhalation of ambient air and through dermal contact with products containing 1-tetracosanol(SRC).