And they said filters kept it from escaping into the air outside.

To keep any of the gas from escaping, the air pressure in the building will be kept lower than the outside atmosphere.

And not for itself, but to keep people from escaping.

He realized two things; first, that this guard had not been set up about the house to keep R-1 from escaping.

"How can you call it murder if they're only trying to keep from escaping your justice? "

Why, to keep the ladies from escaping, if those are allowed to walk outdoors by day.

He opened his door, stepped outside, and shut it quickly, trying to keep the little heat in the room from escaping.

There would be nothing I could do to keep her from escaping.

Had they done this to his eyes to keep him from escaping?

They still had to keep any from escaping to give the warning.