236 Modern Welding Copyright Goodheart-Willcox Co., Inc. Do not weld in wet or damp areas. Avoid elec- tric shock by working on a dry fl oor, and wearing dry welding gloves. Do not touch energized parts of the welding gun with bare skin or wet gloves. A fatal shock could result. Protect welding cables from dam- age to prevent electrical hazards. Arc welding should be done only in an area that is well-ventilated. Fumes are generated by GMAW and especially FCAW electrodes. Position yourself so the fumes do not enter your welding helmet. If there is a slight breeze in the factory or on the job site, try to be on the upwind side. An exhaust system can be used to draw any fumes away from you before they enter your breathing area. You can also wear a positive-pressure respirator, which forces fi ltered or fresh air into your helmet. Carbon monoxide gas is generated when CO 2 is used as a shielding gas. Ozone, a highly toxic gas, is also produced during GMAW and FCAW. Welding should not be performed on any base metals with chemicals on them. Even metals that previously had chemicals on or in them must be cleaned per codes prior to welding. Many chemicals are hazardous or become hazardous when exposed to the heat of welding. Hot metal can cause severe burns. Always use pliers or other approved tools to handle hot metal. Treat all metal in the welding area as if it were hot. Handle shielding gas cylinders with great caution. Chapters 1, 12, and 13 cover handling high-pressure cylinders. Chapters 12 and 13 also contain instructions for setting up regulators and other gas equipment. Glen Jones/Shutterstock.com Gas metal arc welding is a common welding process in heavy industry due to its high production speed and versatility.