3,3-Dimethyl-2-butanol

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 150(SRC), determined from a log Kow of 1.48(2)and a regression-derived equation(3), indicates that pinacolyl alcohol is expected to have high mobility in soil(SRC). Volatilization of pinacolyl alcohol from moist soil surfaces may be an important fate process(SRC) given an estimated Henry's Law constant of 1.8X10-5 atm-cu m/mole(SRC) using a fragment constant estimation method(4). Pinacolyl alcohol is expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 8.8 mm Hg(SRC) determined from a fragment constant method(5). Biodegradation data for pinacolyl alcohol were not available(SRC, 2009).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 150(SRC), determined from a log Kow of 1.48(2) and a regression-derived equation(3), indicate that pinacolyl alcohol is not expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces may be important(3) based upon an estimated Henry's Law constant of 1.8X10-5 atm-cu m/mole(4) 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 53 hours and 19 days, respectively(SRC). According to a classification scheme(5), an estimated BCF of 2.8(SRC), from its log Kow(2) and a regression-derived equation(6), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Biodegradation data for pinacolyl alcohol were not available(SRC, 2009).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), pinacolyl alcohol, which has an estimated vapor pressure of 8.8 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 pinacolyl 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 42 hours(SRC), calculated from its rate constant of 9.2X10-12 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). Pinacolyl alcohol does not contain chromophores that absorb at wavelengths >290 nm(4) and therefore is not expected to be susceptible to direct photolysis by sunlight(SRC).

/AQUATIC SPECIES/ The aquatic toxicity of a secondary alcohol, 3,3-dimethyl-2-butanol (pinacolyl alcohol (PA)), was determined. Acute tests were conducted on Pimephales promelas, 48 hr EC50 = 443.1 mg PA/L, and Daphnia magna, 24 hr EC50 = 513.2 mg PA/L. Growth inhibition tests (96 hr) were conducted using Ankistrodesmus falcatus, EC50 = 257.7 mg PA/L. In general, the toxicity of straight-chained alcohols increases proportionally with the molecular weights. Using the structure activity equation (Log EC50 = 1.10 (LogP) + 0.05 (LogP)squared - 1.22) for P. promelas, the calculated toxicity of PA (EC50 = 547.0 mg/L) agrees with experimental determinations.

The Koc of pinacolyl alcohol is estimated as 150(SRC), using a log Kow of 1.48(1) and a regression-derived equation(2). According to a classification scheme(3), this estimated Koc value suggests that pinacolyl alcohol is expected to have high mobility in soil.

An estimated BCF of 2.8 was calculated for pinacolyl alcohol(SRC)using a log Kow of 1.48(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 pinacolyl alcohol is estimated as 1.76X10-5 atm-cu m/mole at 25 °C(SRC) using a fragment constant estimation method(1). This Henry's Law constant indicates that pinacolyl alcohol 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 53 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 19 days(SRC). Pinacolyl alcohol's Henry's Law constant indicates that volatilization from moist soil surfaces may occur(SRC). Pinacolyl alcohol is expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 8.8 mm Hg(SRC), determined from a fragment constant method(3).

/LABORATORY ANIMALS: Acute Exposure/ Sprague-Dawley rats were given 15, 70 and 140 min exposures to 15 mg/L pinacolyl alcohol (PA), or 6-hour exposures to 0.2, 1.0 and 5.0 mg/l PA (1 mg/L = 240 ppm). A 50% mortality rate was obtained at the longest exposure to 15 mg/L. Sex related differences in the blood levels of PA and pinacolone were noted, and the surviving male rats failed to gain weight normally in the first week after exposure. In rats exposed to 5.0 mg/L for 6 hours, there were reductions in horizontal and vertical activity and the minute volume was 55% of controls at the end of exposure. Like many secondary alcohols, PA poses only a possible inhalation hazard; however, male rats may be somewhat more susceptible than females.

/LABORATORY ANIMALS: Acute Exposure/ Rat data showed the kidney, ureter, and bladder to be effected, changes in the tubules including acute renal failure and acute tubular necrosis in some cases.

/LABORATORY ANIMALS: Subchronic or Prechronic Exposure/ Four groups of male and female Sprague-Dawley rats were exposed for 13 weeks to 3,3-dimethyl-2-butanol (Pinacolyl alcohol (PA)) at concentrations of 0.00, 0.20, 1.00 or 5.00 mg/L (1 mg/l = 240 ppm). Exposures were for 6 hr per day, 5 days per week with sacrifices at 7 and 13 weeks of exposure, and at 4 weeks after exposure. The test animals were evaluated for abnormalities in physiology, behavior, clinical laboratory parameters, and gross and microscopic morphology. No abnormalities were detected in electrocardiograms, respiratory indices, spontaneous activity, passive avoidance activity and open-field behaviour. Clinical signs related to PA exposure included alopecia, ataxia and lacrimation. There were no biologically significant between-group differences in body-weights during the study. The clinical laboratory data demonstrated a 30% increase in serum cholesterol and bilirubin at 7 weeks in high-dose males and an increase in urea nitrogen in intermediate and high-dose males at 13 weeks. There were no abnormalities in hematologic or coagulation parameters. At necropsy there were no significant gross abnormalities; however, examination of organ weights revealed enlarged kidneys in high-dose male rats at 13 weeks, enlarged ovaries in high-dose female rats at 13 weeks, and microscopic study of tissue sections revealed minimal to mild renal tubular injury in high and possibly intermediate dose males at several sacrifices. These findings suggest that the primary target organ of PA, when given by inhalation, is the kidney in male rats and possibly the ovary in female rats. The renal changes in the high-dose males were not fully reversible during the recovery period.

/LABORATORY ANIMALS: Neurotoxicity/ Rat studies shown to have similar effects to ethanol on the CNS, ataxia, and CNS depression.

/ALTERNATIVE and IN VITRO TESTS/ ... The CellSoft computer-assisted digital image analysis system...was used to follow motion parameter changes occurring in spermatozoa incubated for 6 hr with or without exposure to chemicals. Mean amplitude of lateral head displacement (AALH) increased over the 6 hr period, while curvilinear velocity (Vc) first increased and then decreased. Values for linearity (Lin), or beat cross frequency (BCF), were unchanged. The majority of spermatozoa progressed linearly, with rapid rotation of the sperm head, but subpopulations of spermatozoa with different swimming patterns appeared after 1-3 hr of incubation. Percentage motile sperm and Vc were most sensitive to the action of the compounds (pyrogallol, hydroquinone, ammonium oxalate, triethyl phosphite, and pinocolyl alcohol), while BCF was least affected...

The rate constant for the vapor-phase reaction of pinacolyl alcohol with photochemically-produced hydroxyl radicals has been estimated as 9.2X10-12 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 42 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). Pinacolyl alcohol is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(2). Pinacolyl alcohol does not contain chromophores that absorb at wavelengths >290 nm(2) and therefore is not expected to be susceptible to direct photolysis by sunlight(SRC).