4.2 Cleanroom environments

Cleanrooms are semi-closed environments in which bioburden can be monitored. Environmental conditions that might affect spacecraft instruments, e.g., humidity, temperature, might also be closely controlled. Cleanrooms must comply with international standards as defined by the International Standard Organization (ISO), regardless of whether they are being used for building spacecraft or other types of activity that might require cleanliness (e.g., healthcare and medicine, food).