Space Toxicology Laboratory

    Exposure Guidelines (SMACs & SWEGs)



    The JSC toxicologists, in collaboration with the National Research Council's Committee on Toxicology (NRC COT), establish guidelines for safe and acceptable levels of individual chemical contaminants in spacecraft air(SMACs) and drinking water (SWEGs). The rationales for the values set are documented in books published by the National Academy Press. A table listing all the official NASA SMAC values is published in JSC 20584 (Last revised - November 2008).

    Those SMAC values which were published before the beginning of NASA's collaboration with the NRC COT and for which sufficient documentation of the rationales is unavailable are now no longer considered official. Unofficial SMACs, as well as "interim", "temporary" or "tentative" SMAC values will continue to be listed in NASA Marshall Space Flight Center's Materials and Processes Technical Information System ("MAPTIS") database. For access to the MAPTIS database, please e-mail Linda Huber.

    Spacecraft Maximum Allowable Concentrations for Selected Airborne Contaminants

    Click on the book to read the chapters for specific compounds at the National Academy of Sciences web site. You can also perform searches for specific information within each chapter. Click on the text links below to view lists of the chemicals included in each volume.

    SMACs Volume5 nap Tables of Contents


    Spacecraft Water Exposure Guidelines for Selected Waterborne Contaminants

    Space Toxicology Group has compiled all official spacecraft water exposure guidelines into a single document, released as JSC 63414 (Last revised - November 2008).

    SWEGs Volume 1 nap Click on the book to read the chapters for specific compounds at the National Academy of Sciences web site. You can also perform searches for specific information within each chapter. Click on the text links below to view lists of the chemicals included in each volume.

    Tables of Contents