The Hazards of MIG Welding on Mild Steel

MIG welding is very hazardous if you do it improperly.

MIG welding is an approach that relies on the use of inert shielding gas. Like all other types of welding, it can potentially pose severe personal hazards if you don't observe safety precautions. Although mild steel is unlikely to pose any special dangers, MIG welding involves some unique hazards associated with the shielding gas and the byproducts of the process.

Steel

Mild or low-carbon steel is a common construction material, and depending on the kinds of jobs you perform, you may find much of your work deals with mild steel. You have to be careful when welding carbon-rich steels to avoid cracking, but mild steels don't typically require unusual precautions. Regardless of the type of steel, however, welding is an inherently dangerous activity, so safety must always be a paramount concern.

Heat & Light

The intense heat created by the welding torch can cause severe burns, and sparks can potentially damage or destroy your eyes. Welding emits substantial amounts of UV light -- the same damaging form of radiation that causes skin cancer -- and intense infrared radiation. Without protection, this radiation may cause skin burns or damage your eyes in ways that could result in permanent blindness. Over time, loud noise can potentially reduce the sensitivity of your hearing.

Shielding Gas

Shielding gases like argon and nitrogen can quickly reach high concentrations in confined spaces. If the concentration becomes too high, the shielding gas will take the place of the air you would normally breathe and suffocate you. Argon tends to accumulate in low areas because it's heavier than air, and like nitrogen and helium, it has no scent. Inhaling pure argon can cause you to lose consciousness, often without much warning beforehand.

Gases

MIG welding also generates potentially toxic byproducts. Fumes may contain dangerous particulate matter or heavy metals, depending on the coatings on the steel items you're welding. The process may also create ozone, nitric oxide, nitrogen dioxide and carbon monoxide, all of which are toxic gases. If the mild steel has paint or primer coatings or has been treated with organic solvent, welding can potentially unleash a wide variety of organic compounds; the Texas Department of Insurance notes it's difficult to predict what you'll find in the fumes at that point, given the number of possible products from different kinds of carbon compounds.

References

• TWI: What Are the Hazards From Gases During Welding and Cutting?
• Center to Protect Workers' Rights: Welding Fumes and Gases
• Delta School of Trades: Welding Carbon Steel
• Texas Department of Insurance: Welding Hazards Safety Program