The fastest cross country half marathon wearing a functioning gas mask is 2 hr 35 min 51 sec achieved by Team X-T.R.E.M.E. members Jeremy Soles, Jim Snyder, Matt Small, Colin Bunn, and Ben Dyer (all USA) at the XTERRA XDURO 21K in Richmond, Virginia, USA, on 11 June 2011. The gas mask used by each team member was a fully-functioning Avon Protection C50.

All five team members crossed the finish line side by side, simultaneously setting the record. Team X-T.R.E.M.E. dedicated the run to SSgt. Ryan Major of the United States Army, who was injured while serving in Iraq.