Spacecraft Maximum Allowable Concentrations for Selected Airborne Contaminants Volume 3 (1996) / Chapter Skim
Currently Skimming:
B3: tert-Butanol
B3: tert-Butanol
Pages 78-104
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 78... ...
Synonyms: 2-methyI-2-propanol, tert-buty} alcohol, tertiary butanol, t-butano! Formula: CAS number: Molecular weight: Boiling point: Melting point: Specific gravity: Vapor pressure: Lower flammability limit: Solubility: Conversion factors: (CH3~3COH 75-65-0 74.1 82°C 25°C 0.79 42 mmHg at 25°C 2.4% Soluble in water, miscible with ethanol and other organic solvents lppm=3.0Smg/m3 1 mg/m3 = 0.325 ppm 78
|
From page 79... ...
Elimination Because the metabolic pattern for tert-butanol is qualitatively and quantitatively much different from primary and secondary butanols, its means of elimination differs from that of other butanols. The "major portion" of a 500-mg/kg oral dose given to rats was exhaled as the iAssumes vol/vol dilution.
|
From page 80... ...
(1981) reported that female rats given 25 mmol/kg (~.8 g/kg)
|
From page 81... ...
Some animal models indicate that much of the alcohol is eliminated unchanged by respiration, and a lesser amount is conjugated to glucuronic acid and excreted in the kidney (Bechte} and Cornish, 1975; Kami!
|
From page 82... ...
were reported in male rats given oral doses as low as 1.0% (wt/vol) in drinking water (Lindamood et al., 1992~.
|
From page 83... ...
An abstract, data tables, and a pathologist's summary of observations were made available on a subchronic inhalation study contracted by the National Toxicology Program (NTP) and conducted in 1988 by Battelle (1988b)
|
From page 84... ...
Shifts in the relative counts of white blood cells were reported in female rats exposed by inhalation at 2100 ppm (Battelle, 1988b)
|
From page 85... ...
In mice, 6 of 10 males and 4 of 10 females in the high-dose group died. Male and female rats had reduced urinary volumes in association with crystaluria (probably uric acid)
|
From page 86... ...
The incidence of transitional epithelial hyperplasia in rat kidney was statistically increased in males exposed at 2.5 and 5.0 mg/mL and in females at 10 mg/mL. The average severity of nephropathy in female rats increased from 1.6 in controls to 2.9 in the high-dose group (one, minimally; two, mildly, and three, moderately)
|
From page 87... ...
Reproductive Toxicity Studies were not found that examined the in vivo functional capacity of the reproductive system after exposure to tert-butanol; however, histological evidence from the 2-y drinking-water study gave no indication of reproductive effects (NTP, 19941. No increased incidence of lesions was found in male rats and mice after histopathological examination of the epididymis, penis, preputial gland, prostate, seminal vesicle, and testes.
|
From page 88... ...
Dams exposed at 2000, 3500, or 5000 ppm for 7 hid during gestational days ~ to 19 produced fetuses with subnormal weight gain (all three exposures) and increased skeletal variations (top two exposures)
|
From page 89... ...
(1989) concluded that developmental effects would be likely to occur only in the presence of maternal toxicity.
|
From page 90... ...
go ·c~ · x a EM c)
|
From page 91... ...
91 ~- ^ ~ ~en ~ ~at ce on oo ~^ ^ ^ ~cd cd 'e 'e oo ~oO ~a' ~ ~o o ~ ~ ~ ~ ~ ~ m^ =^ ~ =^ ~ ,~ o ~o 4^ 4^ 4^ 4^ .= ~ ~ ~ ~ ~ ~ ~ Ad A - ~A' ~ ~ cn ~ct a ~ 0= ~ ~ ~ ~ ,, ~ ~ ~ aft 5 ~ ~ ~ D ~D D ~o ~ ~ ~m o ~ ~ Z ~ Z Z ~ ~ ~ ~ ~ .
|
From page 93... ...
TABLE 3-S Spacecraft Maximum Allowable Concentrations Exposure Concentration, Concentration, Duration ppm mg/m3 50 50 50 50 Target Toxicity CNS depression CNS depression CNS depression Kidney injury, CNS depression Kidney injury, CNS depression, urinarybladder injury 1 h 24 h 7 d 30 d 180 d 40 150 150 150 150 120 RATIONALE FOR ACCEPTABLE CONCENTRATIONS Because no data are available on human exposures to tert-butanol, the rationale for acceptable concentrations must depend entirely on data obtained in animal models. in 1987, WHO considered the toxicity data base inadequate for setting occupational exposure guidelines, and in 1989, the Cosmetics Ingredient Review Expert Pane} concluded that the available data were insufficient to support the safety of tert-butano!
|
From page 94... ...
. This limit is independent of exposure time since blood concentrations stabilize a few hours after the start of an exposure and prolonged exposure leads to reduced blood concentrations for a given airborne concentration (McComb and Goldstein, 1979a)
|
From page 95... ...
, as was evident in the 2-y drinking-water study (NTP, 1994~. The risk analysis for renal injury must consider the fact that nephropathy was reported only in female rats in the 13-w drinking water study, and only in male rats in the 13-w inhalation study.
|
From page 96... ...
for extrapolation to shorter exposure times, that is, by not increasing the exposure concentration. Using the default species factor of 10, the 7-d AC was calculated to be 650 mg/m3 for nephropathy.
|
From page 97... ...
by any route; however, the incidence of follicular-cell hyperplasia statistically increased in male mice given the alcohol in drinking water for 2 y at concentrations of 5, 10, or 20 mg/mL and in female mice given 10 or 20 mg/mL. The incidence of follicular-cell adenomas was increased only in the 20-mg/mL group of female mice.
|
From page 98... ...
. Because the highest concentration in the rodent inhalation study was 2100 ppm, it is very unlikely that a less susceptible species, such as humans, would have a significant risk of thyroid tumors at a 40-fold lower concentration (50 ppm vs.
|
From page 100... ...
Other alcohols show significant irritant properties and cause readily measured performance decrements. The data base for long-term exposures appears to be relatively complete, particularly in view of the recent completion of a 13-w inhalation study.
|
From page 101... ...
1989. The pharmacokinetics of tertiary butanol.
|
From page 102... ...
1990. The in vivo erythrocyte micronucleus test: Measurement at steady state increases assay efficiency and permits integration with toxicity studies.
|
From page 103... ...
1992. Guidelines for Developing Spacecraft Maximum Allowable Concentrations for Space Station Contaminants.
|
From page 104... ...
1960. Relative intoxicating effects on rats of ethyl, propy!
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.