Methods for Developing Spacecraft Water Exposure Guidelines


Book Description

The National Aeronautics and Space Administration (NASA) maintains an active interest in the environmental conditions associated with living and working in spacecraft and identifying hazards that might adversely affect the health and well-being of crew members. Despite major engineering advances in controlling the spacecraft environment, some water and air contamination appears to be inevitable. Several hundred chemical species are likely to be found in the closed environment of the spacecraft, and as the frequency, complexity, and duration of human space flight increase, identifying and understanding significant health hazards will become more complicated and more critical for the success of the missions. NASA asked the National Research Council (NRC) Committee on Toxicology to develop guidelines, similar to those developed by the NRC in 1992 for airborne substances, for examining the likelihood of adverse effects from water contaminants on the health and performance of spacecraft crews. In this report, the Subcommittee on Spacecraft Water Exposure Guidelines (SWEGs) examines what is known about water contaminants in spacecraft, the adequacy of current risk assessment methods, and the toxicologic issues of greatest concern.




Methods for Developing Spacecraft Water Exposure Guidelines


Book Description

The National Aeronautics and Space Administration (NASA) maintains an active interest in the environmental conditions associated with living and working in spacecraft and identifying hazards that might adversely affect the health and well-being of crew members. Despite major engineering advances in controlling the spacecraft environment, some water and air contamination appears to be inevitable. Several hundred chemical species are likely to be found in the closed environment of the spacecraft, and as the frequency, complexity, and duration of human space flight increase, identifying and understanding significant health hazards will become more complicated and more critical for the success of the missions. NASA asked the National Research Council (NRC) Committee on Toxicology to develop guidelines, similar to those developed by the NRC in 1992 for airborne substances, for examining the likelihood of adverse effects from water contaminants on the health and performance of spacecraft crews. In this report, the Subcommittee on Spacecraft Water Exposure Guidelines (SWEGs) examines what is known about water contaminants in spacecraft, the adequacy of current risk assessment methods, and the toxicologic issues of greatest concern.




Refinements to the Methods for Developing Spacecraft Exposure Guidelines


Book Description

Human spaceflight is inherently risky, with numerous potential hazards posed at each phase of a mission. Potential health risks during spaceflights include short-term health consequences from being in microgravity, as well as long-term health consequences that arise, or continue, months or years after a flight. Additional health considerations are risks posed by exposure to environmental contaminants onboard spacecraft. Because the International Space Station and spacecraft are closed environments that require recirculation of air and water supplies, some contamination of the air and water will occur. Even with onboard air and water purification systems, chemicals will accumulate in the air and water as they recirculate or are recycled onboard. Therefore, it is necessary for the National Aeronautics and Space Administration (NASA) to identify hazardous contaminants and determine exposure levels that are not expected to pose a health risk to astronauts. NASA uses spacecraft maximum allowance concentrations (SMACs) and spacecraft water exposure guidelines (SWEGs) to provide guidance on acceptable exposures to air and water contaminants during normal operations and emergency situations. Refinements to the Methods for Developing Spacecraft Exposure Guidelines updates the methods for establishing SMACs and SWEGs and assists NASA with identifying chemicals that need updated SMACs or SWEGs and new chemicals for which these guidelines should be developed.




Spacecraft Water Exposure Guidelines for Selected Contaminants


Book Description

The International Space Station is a closed and complex environment, so some contamination of its internal atmosphere and water system is expected. To protect space crews from contaminants in potable and hygiene water, the National Aeronautics and Space Administration (NASA) requested that the National Research Council (NRC) provide guidance on how to develop water exposure guidelines and review NASA's development of the exposure guidelines for specific chemicals. NASA selects water contaminants for which spacecraft water exposure guidelines (SWEGs) will be established; this involves identifying toxicity effects relevant to astronauts and calculating exposure concentrations on the basis of those end points. SWEGs are established for exposures of 1, 10, 100, and 1,000 days. This report is the second volume in the series, Spacecraft Water Exposure Guidelines for Selected Chemicals. SWEG reports for acetone, alkylamines, ammonia, barium, cadmium, caprolactam, formate, formaldehyde, manganese, total organic carbon, and zinc are included in this report. The committee concludes that the SWEGs developed for these chemicals are scientifically valid based on the data reviewed by NASA and are consistent with the NRC (2000) report, Methods for Developing Spacecraft Water Exposure Guidelines. SWEG reports for additional chemicals will be presented in a subsequent volume.




Spacecraft Water Exposure Guidelines for Selected Contaminants


Book Description

The International Space Station is a closed and complex environment, so some contamination of its internal atmosphere and water system is expected. To protect space crews from contaminants in potable and hygiene water, the National Aeronautics and Space Administration (NASA) requested that the National Research Council (NRC) provide guidance on how to develop water exposure guidelines and review NASA's development of the exposure guidelines for specific chemicals. NASA selects water contaminants for which spacecraft water exposure guidelines (SWEGs) will be established; this involves identifying toxicity effects relevant to astronauts and calculating exposure concentrations on the basis of those end points. SWEGs are established for exposures of 1, 10, 100, and 1,000 days. This report is the second volume in the series, Spacecraft Water Exposure Guidelines for Selected Chemicals. SWEG reports for acetone, alkylamines, ammonia, barium, cadmium, caprolactam, formate, formaldehyde, manganese, total organic carbon, and zinc are included in this report. The committee concludes that the SWEGs developed for these chemicals are scientifically valid based on the data reviewed by NASA and are consistent with the NRC (2000) report, Methods for Developing Spacecraft Water Exposure Guidelines. SWEG reports for additional chemicals will be presented in a subsequent volume.




Safety Design for Space Systems


Book Description

Progress in space safety lies in the acceptance of safety design and engineering as an integral part of the design and implementation process for new space systems. Safety must be seen as the principle design driver of utmost importance from the outset of the design process, which is only achieved through a culture change that moves all stakeholders toward front-end loaded safety concepts. This approach entails a common understanding and mastering of basic principles of safety design for space systems at all levels of the program organisation. Fully supported by the International Association for the Advancement of Space Safety (IAASS), written by the leading figures in the industry, with frontline experience from projects ranging from the Apollo missions, Skylab, the Space Shuttle and the International Space Station, this book provides a comprehensive reference for aerospace engineers in industry. It addresses each of the key elements that impact on space systems safety, including: the space environment (natural and induced); human physiology in space; human rating factors; emergency capabilities; launch propellants and oxidizer systems; life support systems; battery and fuel cell safety; nuclear power generators (NPG) safety; habitat activities; fire protection; safety-critical software development; collision avoidance systems design; operations and on-orbit maintenance. - The only comprehensive space systems safety reference, its must-have status within space agencies and suppliers, technical and aerospace libraries is practically guaranteed - Written by the leading figures in the industry from NASA, ESA, JAXA, (et cetera), with frontline experience from projects ranging from the Apollo missions, Skylab, the Space Shuttle, small and large satellite systems, and the International Space Station - Superb quality information for engineers, programme managers, suppliers and aerospace technologists; fully supported by the IAASS (International Association for the Advancement of Space Safety)




Safety Design for Space Systems


Book Description

The lack of widespread education in space safety engineering and management has profound effects on project team effectiveness in integrating safety during design. On one side, it slows down the professional development of junior safety engineers, while on the other side it creates a sectarian attitude that isolates safety engineers from the rest of the project team. To speed up professional development, bridge the gap within the team, and prevent hampered communication and missed feedback, the entire project team needs to acquire and develop a shared culture of space safety principles and techniques.The second edition of Safety Design for Space Systems continues to address these issues with substantial updates to chapters such as battery safety, life support systems, robotic systems safety, and fire safety. This book also features new chapters on crew survivability design and nuclear space systems safety. Finally, the discussion of human rating concepts, safety-by-design principles, and safety management practices have also been revised and improved. With contributions from leading experts worldwide, this second edition represents an essential educational resource and reference tool for engineers and managers working on space projects. - Provides basic multidisciplinary knowledge on space systems safety design - Addresses how space safety engineering and management can be implemented in practice - Includes new chapters on crew survivability design and nuclear space systems safety - Fully revised and updated to reflect the latest developments in the field




Acute Exposure Guideline Levels for Selected Airborne Chemicals


Book Description

Acute Exposure Guideline Levels for Selected Airborne Chemicals, Volume 15 identifies, reviews, and interprets relevant toxicologic and other scientific data for ethyl mercaptan, methyl mercaptan, phenyl mercaptan, tert-octyl mercaptan, lewisite, methyl isothiocyanate, and selected monoisocyanates in order to develop acute exposure guideline levels (AEGLs) for these high-priority, acutely toxic chemicals. AEGLs represent threshold exposure limits (exposure levels below which adverse health effects are not likely to occur) for the general public and are applicable to emergency exposures ranging from 10 minutes (min) to 8 h. Three level--AEGL-1, AEGL-2, and AEGL-3--are developed for each of five exposure periods (10 min, 30 min, 1 h, 4 h, and 8 h) and are distinguished by varying degrees of severity of toxic effects. This report will inform planning, response, and prevention in the community, the workplace, transportation, the military, and the remediation of Superfund sites.




Review of DOD's Approach to Deriving an Occupational Exposure Level for Trichloroethylene


Book Description

Trichloroethylene (TCE) is a solvent that is used as a degreasing agent, a chemical intermediate in refrigerant manufacture, and a component of spot removers and adhesives. It is produced in mass quantities but creates dangerous vapors and is an environmental contaminant at many industrial and government facilities, including facilities run by the U.S. Department of Defense (DoD). It is important to determine the safe occupational exposure level (OEL) for the solvent in order to protect the health of workers who are exposed to its vapors. However, there are concerns that the current occupational standards insufficiently protect workers from these health threats. Review of DOD's Approach to Deriving an Occupational Exposure Level for Trichloroethylene makes recommendations to improve the DoD's approach to developing an OEL for TCE, strengthen transparency of the process, and improve confidence in the final OEL value. This report reviews the DoD's approach using a literature review, evidence synthesis based on weight of evidence [WOE], point-of-departure derivation, physiologically based pharmacokinetic modeling, extrapolation tools, and explores other elements of the process of deriving an OEL for TCE. It examines scientific approaches to developing exposure values and cancer risk levels, defining the scope of the problem, and improving hazard identification.




Spacecraft Maximum Allowable Concentrations for Selected Airborne Contaminants


Book Description

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.