Welding, cutting and heating of toxic metals is a dangerous and hazardous job.  Adequate ventilation must be provided to protect the welder and other employees from toxic fumes and gases released during the welding process.  Always wear all required personal protective equipment and follow all safe welding procedures to help eliminate hazards posed by the chemical agents used during welding.  Some of the metals and their hazards used during welding include:

Beryllium.  This is sometimes used as an alloying element with copper and other base metals.  Acute exposure to high concentrations can result in chemical pneumonia.  Chronic exposure (long-term) may result in cough, weight loss, shortness of breath, and fatigue.

Zinc. This is used in large quantities when manufacturing brass, galvanized metals and other alloys. 

Exposure to zinc fumes during the welding process may cause metal fume fever.  Metal fume fever symptoms are similar to the flu.

Iron Oxide.  Iron is the principle alloying substance in the manufacture of steel.  Iron oxide fumes arise during welding not only from the base metal, but also the electrode.  Acute affect results in irritation of nasal passages, throat and lungs.

Cadmium.  Frequently used as a rust-preventive coating on steel.  Acute exposure to high levels of cadmium fumes may produce pulmonary edema, severe lung irritation and even death.  Long-term exposure can result in kidney damage or emphysema.  Cadmium is classified as a potential cancer-causing agent.