Apple has stated that it has not found any evidence to back up a French newspapers claims that Mac Pros are emitting benzene a toxic gas.
The original article in Libération claimed that Mac Pros build before 2008 emit an odour which contains several toxins including benzene which if can cause diseases such as cancer if exposure is prolonged.
Apple spokesman Bill Evans told Macworld, "We have not found anything that supports this claim, but continue to investigate it for the customer."