When working with flammable liquids, a potential hazard arises because of the possibility that sparks produced by metal tools striking each other might ignite the liquid or its vapour. In these circumstances, Non-sparking tools may be used. These are generally made from beryllium-copper or aluminium-bronze and significantly reduce the possibility of igniting dusts, gases, or flammable vapors. Although these tools may emit some sparks when striking metal, the sparks have a low heat content and are not likely to ignite most flammable liquids.