Spacecraft Maximum Allowable Concentrations for Selected Airborne Contaminants Volume 2 (1996) / Chapter Skim
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B1 Acrolein
B1 Acrolein
Pages 19-38
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From page 19... ...
Synonyms: Formula: CAS number: Molecular weight: Boiling point: Melting point: Vapor pressure: Conversion factors at25°C,latm: 2-Propenal, acrylic aldehyde CH2CHCHO 107-02-08 56 52.7°C -87 o C 214 mm Hg at 20°C 1 ppm = 2.29 mg/m3 1 mg/m3 = 0.44 ppm OCCURRENCE AND USE Acrolein is not used in the spacecraft, but acrolein is a potential atmospheric contaminant in spacecraft because it was found to be offgassed from the hardware of two Spacelab missions at a rate of 0.007 mg/d (Geiger, 19841.
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From page 20... ...
TOXICITY SUMMARY The major toxicity of acrolein is mucosal irritation. Acute and Short-Term Toxicity Mucosal Irritation The NRC's Committee on Toxicology cited a report by the Shell Chemical Corporation that acrolein produced moderate mucosal irritation at a concentration as low as 0.25 ppm in humans, but no information on the exposure duration was given (Shell Chemical Corp., 1958~.
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From page 21... ...
A 40-60 min exposure to acrolein at 0.3 ppm caused moderate eye irritation and slight nose irritation (WeberTschopp et al., 19771. In a 1.5-min exposure of human volunteers to acrolein, 0.6 ppm produced the same degree of irritation in the eyes and the nose (somewhat slight irritation)
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From page 22... ...
In guinea pigs exposed to acrolein at 0.4-1.0 ppm for 2 h, there were decreases in the respiratory rate and increases in the total pulmonary resistance (Murphy et al., 1963~. The respiratory effects of acrolein in both the mouse and guinea pig are readily reversible when the exposure ends (Steinhagen and Barrow, 1984; Murphy et al., 1963~.
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From page 23... ...
Dogs, rats, and guinea pigs were similarly exposed in the same study, but the rats and guinea pigs appeared to be less susceptible to acrolein than the monkeys; the rats and guinea pigs did not show any gross sign of irritation, tracheal metaplasia, or tracheal hyperplasia (Lyon et al., 1970~. Only two dogs were used in each exposure group, and in general the clinical signs of eye and nose irritation as well as lung injury in the dogs were similar to those in the monkeys.
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From page 24... ...
A similar exposure at 1.0 ppm was found to cause focal liver necrosis in guinea pigs and rats. The meaning of the finding of liver necrosis is uncertain, because a 90-d continuous exposure at a higher concentration of 1.S ppm failed to induce liver necrosis in the guinea pigs and rats (Lyon et al., 19701 In addition to the Lyon et al.
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From page 25... ...
classified acrolein as a possible human carcinogen on the basis of limited animal carcinogenicity data, mutagenicity in bacteria, and structural similarity with two probable human carcinogens, formaldehyde and acetaldehyde (EPA, 1990~. A 1-y exposure of hamsters to acrolein at 4 ppm failed to cause any increase in tumor incidence (Feron and Kruysse, 19771.
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2 6 SMACS FOR SELECTED AIRBORNE CONTAMINANTS sister chromatic exchange in Chinese hamster ovary ceils (Au et al., 1980~. However, acrolein failed to affect the dominant lethal assay in mice after an intraperitoneal injection (Epstein et al., 1972~.
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28 Cd ~ ._ _ Cal .s Vie of o As V)
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29 ~00 _ ~ cat cTN (ON c<: _ C; _ , ~ _ _^ _^ ~ ct , ~_ ~ ~ A ° ° ~ ~ LO m 3 ~ ~ ~ ~ i; ~ ~ 3 ~a Y O ~ 2 ~ ° - E ~ ~ c~.c ~ ~ ~ ~ Y i ~ e A E - ^ a,, ~.
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From page 32... ...
TABLE 1-3 Spacecraft Maximum Allowable Concentrations Duration ppm mg/m3 Target Toxicity 1 h 75 170 Mucosal irritation 24 h 35 80 Mucosal irritation 7 da 15 30 Mucosal irritation 30 d 15 30 Mucosal irritation 180 d 15 30 Mucosal irritation aFormer 7-d SMAC = 50 ppm. RATIONALE FOR ACCEPTABLE CONCENTRATIONS Mucosal irritation is the most important toxic end point to be used in setting SMACs for acrolein because mucosal irritation was detected in humans and mice after exposure to concentrations lower than those that produced histopathological changes in the respiratory systems of various laboratory animal species (Weber-Tschopp et al., 1977; Steinhagen and Barrow, 1984;Lyonetal., 1970;Feronetal., 19781.
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The 1-h and 24-h SMACs are designed for contingency scenarios, so they are aimed at preventing irreversible injuries and significant performance decrements. It is acceptable that these short-term SMACs might not protect against slight mucosal irritation.
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From page 34... ...
Moreover, in dogs exposed repetitively or continuously to acrolein, the signs of mucosal irritation were found to diminish after the first week, indicating the development of reduced susceptibility as acrolein exposure is lengthened (Lyon et al., 1970~. Therefore, long-term SMACs could be established by basing an estimate for a nonirritating concentration of acrolein on data of 1-h exposures.
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From page 35... ...
(1977) , who showed that, in a 1.5-min exposure of human subjects to acrolein, 0.60 ppm produced a slight eye irritation, 0.30 ppm caused a little eye discomfort, and 0.15 ppm resulted in no adverse effects on the eye (going from 0.60 ppm to 0.15 ppm is a factor of 2 x 2, or 41.
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From page 36... ...
1989. Acute vapor inhalation toxicity of acrolein and its influence as a trace contaminant in 2-methoxy-3,4-dihydro-2H-pyran.
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From page 37... ...
1989. Bronchial responsiveness and inflammation in guinea pigs exposed to acrolein.
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From page 38... ...
New York: Van Nostrand Reinhold. Shell Chemical Corp.
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