SCP: Containment Breach is not available for Mac but there are some alternatives that runs on macOS with similar functionality. The best Mac alternative is Amnesia: The Dark Descent. If that doesn't suit you, our users have ranked more than 10 alternatives to SCP: Containment Breach and seven of them are available for Mac so hopefully you can find a suitable replacement. Other interesting Mac alternatives to SCP: Containment Breach are Slender: The Eight Pages (Paid), Alien: Isolation (Paid), Layers of Fear (Paid) and Slender: The Arrival (Paid).
Amnesia: The Dark Descent is a first person survival horror game for Windows, Mac OS X and Linux. The game features a protagonist named Daniel exploring a dark and foreboding castle, while avoiding monsters and other obstructions as well as solving puzzles.
Slender: The Eight Pages is a free indie-developed psychological horror/survival horror video game for Microsoft Windows and OS X. The game is based on the Something Awful forums' creation, Slender Man.
Layers of Fear is an foray into madness, a first-person horror game that sets a tone of fear and dread through provocative story telling as you explore a Victorian setting complete with mood-setting art pieces.
Penumbra: Overture is the first in a series of episodic survival horror games developed by Swedish developer Frictional Games. It was originally intended as the first episode of a trilogy. Represent entire series of Penumbra games.