He would be outside in the open, unfiltered air of Gnala.

And we vented unfiltered air to the outside environment.

Any Tracker breathing unfiltered air was at risk.

"Hate to break it to you, but I've breathed unfiltered air before and didn't take no lasting harm."

Veg knew this, but the unfiltered air seemed unclean and it upset him to inhale it.

This means that contact with unfiltered air may kill him, so he must live out his life in incubator-like conditions.

You were captured last June and you've been breathing unfiltered air ever since.

Once there, we could i:ount on real gravity underfoot, unfiltered air to breathe, and the chance to taste unsynthesized food.

The unfiltered air wrapped itself stickily around me, and I lunged for the window.

This planet's unfiltered air smelled like rotten eggs.