This White Paper is the fruit of collaboration between EUROCONTROL, ROMATSA (Romanian Air Traffic Services Administration) and a team of scientific researchers from the aeronautics and space research centre of Bucharest. It focuses on the safety issues related to atmospheric contamination with volcanic particulate matter.\r\n\r\nEuropean Safety Programme for ATM 2010-2014 (ESP+)\r\nJune 2011 - Edition 1.0