“When discharging industrial gas into the indoor environment in high altitude astronomy, we never wore breathing respirators that fed us oxygenated air at above the legally required 19.5% oxygen levels.” LevelsEnvironmentAirAstronomyBreathingOshaGasAltitudeOxygenLiquidHighAstrophysicsAstronomicalIndustrialAstronomerAstrobiologyFedIndoorAstrosociobiologyLegallyDischargingRespiratorsOxygenated Author:Steven Magee