When you weld galvanized steel, remove the protective coatings next to the haz zone, thus leaving a raw, unprotected area in the weld zone.  This precautions must be taken to avoid porosity and cracking of the weld caused by penetration of zinc into the weld pool while using arc and oxyfuel processes.  Cold Galv can be applied after the welding.

Adequate ventilation combined with proper fume extraction will completely eliminate exposure to welding fumes.