The climbers were roped together for 'safety'. = The climbers were roped together 'for safety's sake'.
There is 'safety in numbers'. [=you are safer in a group of people than you are when you are alone]
His hobbies act as a 'safety valve', relieving some of the pressure he feels from his job.
(..) Come on! This way! Stay there! What are you doin'? Blake, MCU! I'm gettin' these boys to safety! If anyone crosses this bridge, they'll blow the city! It's gonna blow anyway! We need to open this bridge, now! Detective, if you take one step forward, (..)2012 The Dark Knight Rises
(..) I need you to take control of Wayne Enterprises... and this reactor. - To do what with it? - Nothing. Until we can guarantee its safety. - And if we can't? - Decommission it. Flood it. Destroy the world's best chance for a sustainable future? If the world's not ready, yes. (..)2012 The Dark Knight Rises