ATLAS LHC NON-COLLISION BACKGROUND BEAM BACKGROUND COSMICS 2011 2011 In this note we discuss the level of non-collision backgrounds and their properties in the ATLAS experiment. The data is collected with the ATLAS detector at a centre-of-mass energy of 7 TeV during the 2010 proton-proton run and during dedicated data-taking of cosmic-ray data at the Large Hadron Collider (LHC). The objective of the study is the understanding of the characteristics of the non-collision backgrounds in order to identify, estimate and reject them in the physics analyses.