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A large number of chemical and biological materials will be on the International Space Station (ISS) for use in experiments or as utility chemicals. In the event of accidental crew exposure to such materials, the ISS crew, flight controllers, flight surgeons, and toxicologists on the ground will need accurate information about the materials to which the crew was exposed. To meet this need, the HazMat chemical inventory database that is used on the Shuttle is being modified by Johnson Space Center’s (JSC’s) Portable On-board Computing and Tools Group to interface with an in-flight computerized Inventory Management System (IMS) that is being developed for ISS. HazMat will have toxicological information on chemicals and biologicals contained in hardware. IMS will use bar codes to track hardware from the time it is brought on board the ISS (from any supply vehicle) until it is removed from the ISS.

Since the early years of the manned space program, NASA has developed and used exposure limits called Spacecraft Maximum Allowable Concentrations (SMACs) to help protect astronauts from airborne toxicants. Most of these SMACS are based on an exposure duration of 7 days, since this is the duration of a “typical” mission. A set of “contingency SMACs” is also being developed for scenarios involving brief (1-hour or 24- hour) exposures to relatively high levels of airborne toxicants from event-related “contingency” releases of contaminants. The emergency nature of contingency exposures dictates the use of different criteria for setting exposure limits. The NASA JSC Toxicology Group recently began a program to document the rationales used to set new SMACs and plans to review the older, 7-day SMACs. In cooperation with the National Research Council's Committee on Toxicology, a standard procedure has been developed for researching, setting, and documenting SMAC values.