Due to infectious source staying time greatly impact on the safe social distance; we upgrade social distancing into Airflow Inaccessible Distancing code. Airborne infection must rely on airflow for transmission. This new code clearly states that only infectious airflow inaccessible places or where we can use some technological means to sterilize the airflow can be regarded as safe. In practice, a simple plastic film can physically stop any infectious agent to trespass over the film no matter how aggressive it is.