Headspace vials are designed to withstand a small amount of internal pressure, therefore all MicroSolv brand headspace vials have a wall thickness of 1.2mm for added safety, thus it is assured that the vial will not burst. 

Contrary to popular belief, the seal and not the vial represents the weakest part of the entire system. Under pressure the septa will bulge against the aluminum cap with such a force that the cap is torn apart. It has been reported the some of our vials with a pressure relief cap system will hold up to 10 bar but most caps will break up at 10 bars with no pressure relief system in place.