Abstract: Apparatus for protecting persons trapped in burning buildings from injury resulting from breathing of combustion products comprises a plumbing pipe segment disposed between a plumbing trap element and a plumbing system vent line having a releasably sealed port therein. An easily removable fluid sealing cap is installed on the port to provide for normal drain operation. A flexible conduit sealingly attached to a breathing mask at one end and to a fluid sealing connector device adapted to be connected to the port at the other end is also provided. In the event of fire, the user releases the sealing cap from the port and connects the fluid sealing connector at one end of the flexible conduit to the port thereby being provided with access through the mask, conduit, port, and vent line to a supply of building exterior, breathable, air free from harmful combustion products.