Milder excessive exposure may have chronic effects such as pulmonary oedema and skin rashes. Iron is a very common constituent of welding fumes. Acute effects include respiratory irritation. Iron is also capable of causing siderosis, a benign accumulation of iron oxide in the lungs. Manganese is used in most stainless steel carbon alloys and welding electrodes.
Welders are unlikely to be exposed to hazardous concentrations if adequate ventilation is provided.
Lead is found in solder, brass, bronze and is also used as a metal primer and steel coating. Exposures must be controlled to prevent lead poisoning. Molybdenum can cause respiratory irritation and impaired breathing, but welders are unlikely to be exposed to excessive amounts. Nickel is found in many alloys and stainless steel. Eye and throat irritation are acute effects.