books.google.com - 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...http://books.google.com/books/about/Spacecraft_Maximum_Allowable_Concentrati.html?id=3VZRtLk--BAC&utm_source=gb-gplus-shareSpacecraft Maximum Allowable Concentrations for Selected Airborne Contaminants
