I'm not necessarily advocating carrying a $2 Chinese peanut lighter as one's only fire starting method. I'm just pointing out the results of my preliminary tests. While it does rely on an O-ring I agree that lots of things rely on them. Overall O-rings are fairly robust, and the way the lighter is constructed it's hard to imagine just how the O-ring would be subjected to much shock or stress. You could get aftermarket gaskets or carry spares if you were really worried.