Traces of vanadium in significant-temperature combustion products type droplets of molten vanadates. These attack the passivation layers on metals and result in substantial temperature corrosion, which happens to be a priority especially for inner combustion engines. Molten sulfate and lead particulates also have these types of effect. 1970 – https://broadfar.com/non-combusted-cigarettes-a-safer-alternative-or-just-a-myth/