Http://lsag.web.cern .ch/lsag/LSAG-Report .pdf

The Large Hadron Collider (LHC) Safety Assessment Group reviewed the safety of LHC collisions, confirming and updating the 2003 LHC Safety Study Group's conclusions that they present no danger. The LHC reproduces collisions at energies less than those reached by cosmic rays bombarding the Earth, and the stability of astronomical bodies indicates that such collisions are not dangerous. The group studied the possible production of hypothetical objects like vacuum bubbles, magnetic monopoles, microscopic black holes, and strangelets, finding no associated risks. Microscopic black holes would decay by Hawking radiation, and if stable, would be stopped inside the Earth or other astronomical bodies, with their accretion rate constrained by the stability of these bodies. Strangelets are also unlikely to pose a danger, with experimental measurements at RHIC constraining their production. The Universe replicates the LHC's collisions over 10^13 times per second, and the fact that astronomical bodies withstand cosmic-ray bombardment imposes strong upper limits on hypothetical sources of danger.