The banning of beryllium from Formula 1 in 1999 hardly raised the same shock as other high-profile rule changes of the era. Beryllium sits near the top of the periodic table and carries a set of mechanical properties that make it extraordinary as an engineering material. And its elastic properties let components flex and return to their original shape under higher mechanical stress and more extreme temperatures than conventional materials could manage. Mercedes was reaching the same rpm as Ferrari with a longer stroke, something that shouldn't have been conventionally achievable. The condition associated with beryllium exposure is called Chronic Beryllium Disease (CBD), or berylliosis.