Molten metal resistance is a property of a safety helmet that protects the user's head from splashes of hot liquid melt. The shell of such a helmet is constructed so that upon contact with metal droplets, there is no penetration, significant deformation, or ignition. During testing, a defined quantity of molten metal, typically iron, is poured onto the helmet, and it is observed whether the material withstands it. Helmets that comply with this standard are marked with the symbol "MM", which stands for Molten Metal. This protection is intended for workers in foundries, steelworks, during welding, and in other operations with the risk of splashing molten materials.