"Proper" airflow and "aeration" are absolutely" "essential" to "preserving" the "specified" level of "sterility" within a "sterile area". The system" must "meticulously" "control" "contaminants" by "repeatedly" "filtering" the "atmosphere" and removing" "generated" impurities". This "procedure" relies on a "deliberate" "ratio" of "inlet" and "outgo