The National Aeronautics and Space Administration (NASA) is aware of the potential toxicological hazards to crew members that might be associated with prolonged spacecraft missions. Despite major engineering advances in controlling the atmosphere within spacecraft, some contamination of the air appears inevitable. NASA has measured numerous airborne contaminants during space missions. As the missions increase in duration and complexity, ensuring the health and well-being of astronauts traveling and working in this unique environment becomes increasingly difficult. As part of its efforts to promote safe conditions aboard spacecraft, NASA requested the National Research Council (NRC) to develop guidelines for establishing spacecraft maximum allowable concentrations (SMACs) for contaminants, and to review SMACs for various spacecraft contaminants to determine whether NASA's recommended exposure limits are consistent with the guidelines recommended by the subcommittee. In response to this request, the NRC first developed criteria and methods for preparing SMACs for spacecraft contaminants, published in its 1992 report Guidelines for Developing Spacecraft Maximum Allowable Concentrations for Space Station Contaminants. Since then, the NRC's Subcommittee on Spacecraft Maximum Allowable Concentrations has been reviewing NASA's documentation of chemical-specific SMACs. This report is the fourth volume in the series Spacecraft Maximum Allowable Concentrations for Space Station Contaminants. The first volume was published in 1994 and the second and third in 1996. Spacecraft Maximum Allowable Concentrations for Selected Airborne Contaminants: Volume 4 has been reviewed in draft form by individuals chosen for their technical expertise and diverse perspectives in accordance with procedures approved by the NRC's Report Review Committee for reviewing NRC and Institute of Medicine reports. The purpose of that Independent review was to provide candid and critical comments to assist the NRC in making the published report as sound as possible and to ensure that the report meets institutional standards for objectivity, evidence, and responsiveness to the study charge. The review comments and draft manuscript remain confidential to protect the integrity of the deliberative process.

NASA is aware of the potential toxicologic hazards to crew that might be associated with prolonged spacecraft missions. Despite major engineering advances in controlling the atmosphere within spacecraft, some contamination of the air appears inevitable. NASA has measured numerous airborne contaminants during space missions. As the missions increase in duration and complexity, ensuring the health and well-being of astronauts traveling and working in this unique environment becomes increasingly difficult. As part of its efforts to promote safe conditions aboard spacecraft, NASA requested the National Research Council to develop guidelines for establishing spacecraft maximum allowable concentrations (SMACs) for contaminants and to review SMACs for various spacecraft contaminants to determine whether NASA's recommended exposure limits are consistent with the guidelines recommended by the committee. This book is the fifth volume in the series Spacecraft Maximum Allowable Concentrations for Selected Airborne Contaminants, and presents SMACs for acrolein, C3 to C8 aliphatic saturated aldehydes, C2 to C9 alkanes, ammonia, benzene, carbon dioxide, carbon monoxide, 1,2-dichloroethane, dimethylhydrazine, ethanol, formaldehyde, limonene, methanol, methylene dichloride, n-butanol, propylene glycol, toluene, trimethylsilanol, and xylenes.

The National Aeronautics and Space Administration (NASA) has measured numerous airborne contaminants in spacecraft during space missions because of the potential toxicological hazards to humans that might be associated with prolonged spacecraft missions. This volume reviews the spacecraft maximum allowable concentrations (SMACs) for various contaminants to determine whether NASA's recommended exposure limits are consistent with recommendations in the National Research Council's 1992 volume Guidelines for Developing Spacecraft Maximum Allowable Concentrations for Space Station Contaminants.

The National Aeronautics and Space Administration (NASA) has developed spacecraft maximum allowable concentrations (SMACs) for contaminants that might be found in the atmosphere within spacecraft during space missions to ensure the health and well-being of astronauts traveling and working in this unique environment. In volume 1 of this series, NASA developed SMACs for 11 compounds: acetaldehyde, ammonia, carbon monoxide, formaldehyde, Freon 113, hydrogen, methane, methanol, octamethyltrisiloxane, trimethylsilanol, and vinyl chloride. Volume 2 includes SMACs for 12 more airborne contaminants: acrolein, benzene, carbon dioxide, 2-ethoxyethanol, hydrazine, indole, mercury, methylene chloride, methyl ethyl ketone, nitromethane, 2-propoanol, and toluene. In developing SMACs from the toxicological literature, NASA followed the Guidelines for Developing Spacecraft Maximum Allowable Concentrations for Space Station Contaminants published in 1992 by the National Research Council.

The National Aeronautics and Space Administration (NASA) is aware of the potential toxicological hazards to crew members that might be associated with prolonged spacecraft missions. Despite major engineering advances in controlling the atmosphere within spacecraft, some contamination of the air appears inevitable. NASA has measured numerous airborne contaminants during space missions. As the missions increase in duration and complexity, ensuring the health and well-being of astronauts traveling and working in this unique environment becomes increasingly difficult. As part of its efforts to promote safe conditions aboard spacecraft, NASA requested the National Research Council (NRC) to develop guidelines for establishing spacecraft maximum allowable concentrations (SMACs) for contaminants, and to review SMACs for various spacecraft contaminants to determine whether NASA's recommended exposure limits are consistent with the guidelines recommended by the subcommittee. In response to this request, the NRC first developed criteria and methods for preparing SMACs for spacecraft contaminants, published in its 1992 report Guidelines for Developing Spacecraft Maximum Allowable Concentrations for Space Station Contaminants. Since then, the NRC's Subcommittee on Spacecraft Maximum Allowable Concentrations has been reviewing NASA's documentation of chemical-specific SMACs. This report is the fourth volume in the series Spacecraft Maximum Allowable Concentrations for Space Station Contaminants. The first volume was published in 1994 and the second and third in 1996. Spacecraft Maximum Allowable Concentrations for Selected Airborne Contaminants: Volume 4 has been reviewed in draft form by individuals chosen for their technical expertise and diverse perspectives in accordance with procedures approved by the NRC's Report Review Committee for reviewing NRC and Institute of Medicine reports. The purpose of that Independent review was to provide candid and critical comments to assist the NRC in making the published report as sound as possible and to ensure that the report meets institutional standards for objectivity, evidence, and responsiveness to the study charge. The review comments and draft manuscript remain confidential to protect the integrity of the deliberative process.

The National Aeronautics and Space Administration (NASA) has developed spacecraft maximum allowable concentrations (SMACs) for contaminants that might be found in the atmosphere within spacecraft during space missions to ensure the health and well-being of astronauts traveling and working in this unique environment. In volume 1 of this series, NASA developed SMACs for 11 compounds: acetaldehyde, ammonia, carbon monoxide, formaldehyde, Freon 113, hydrogen, methane, methanol, octamethyltrisiloxane, trimethylsilanol, and vinyl chloride. Volume 2 includes SMACs for 12 more airborne contaminants: acrolein, benzene, carbon dioxide, 2-ethoxyethanol, hydrazine, indole, mercury, methylene chloride, methyl ethyl ketone, nitromethane, 2-propoanol, and toluene. In developing SMACs from the toxicological literature, NASA followed the Guidelines for Developing Spacecraft Maximum Allowable Concentrations for Space Station Contaminants published in 1992 by the National Research Council.

The National Aeronautics and Space Administration (NASA) has measured numerous airborne contaminants in spacecraft during space missions because of the potential toxicological hazards to humans that might be associated with prolonged spacecraft missions. This volume reviews the spacecraft maximum allowable concentrations (SMACs) for various contaminants to determine whether NASA's recommended exposure limits are consistent with recommendations in the National Research Council's 1992 volume Guidelines for Developing Spacecraft Maximum Allowable Concentrations for Space Station Contaminants.