What keeps them from revising their outdated 1999 standard is an onerous set of cost-benefit requirements that go far beyond that of any other government agency. If they can’t make an overwhelming case to change a rule, it doesn’t get touched. The requirement works like this: If an incremental safety improvement results in higher manufacturing costs, the realized value of the improvement must outweigh those costs. Preventing a theoretical number of concussions—that’s an extremely hard dollar value to prove.