Steel melts at 2,600-2,800 degrees Fahrenheit. That’s pretty hot and hot enough to vaporize other materials near the weld. Heavy metals, such as lead, mercury, cadmium, iron oxide, and so on, are definitely a concern. Also, physical burns or radiation from the bright light associated with welding can also cause injury. One of the greatest dangers to the home fabricator is welding on steel that has just been cleaned with chlorinated parts cleaner. This can form hydrogen chloride that can quickly damage lung tissue when inhaled. For this reason, we avoid chlorinated parts cleaner and make sure to wait for any parts cleaner to evaporate off any metal we are about to weld.