A gas-tight packaging arrangement for a device, such as a respirator containing an oxygen releasing chemical. The arrangement includes a safety device for checking the state of the packaging. The safety device acts on an elastic partial area of an evacuated envelope surrounding the device. The envelope may be made of foil or the like. The state of the packaging is indicated through a viewing window provided on a housing surrounding the envelope. A loss of vacuum is indicated by providing a tensioned non-elastic band surrounding at least part of the circumference of the envelope. The non-elastic band includes a visible mark band part which may be viewed through the viewing window. The visible mark band part includes a breaking point, the breakage of the visible mark band part being visible through the viewing window. To tension the non-elastic band, a strain relief element may be provided bridging the visible mark band part such that the belt may be tensioned without breaking the visible mark band part.