breathable

adj

1. suitable for breathing

   “The Wards are open-topped, with skyscrapers rising from the superstructure. Towers are sealed against vacuum, as the breathable atmosphere envelope is only maintained to a height of about seven meters. The atmosphere is contained by the centrifugal force of rotation and a "membrane" of dense, colorless sulphur hexafluoride gas, held in place by carefully managed mass effect fields.”

2. (usually)Letting air seep through.

   “breathable paint”

   “If you’re looking for the most breathable mask, Lukovics says, “Cotton is preferable, mainly for absorbing moisture/sweat.” She says multiple layers may be more protective but will also impact breathability.”