Posted On: May 24, 2024

Reducing Hazardous Fumes and Gases During Welding

What are Welding Fumes?

Welding fumes are a mixture of tiny solid particles (fume particles) and gases generated during the welding process. These fumes are produced when the intense heat of welding vaporizes the base metal, filler material, and any surface coatings, which then condense into fine particles and gases in the air.

What is in Welding Fume?

Welding fumes can contain a variety of hazardous substances, including:

• Metal Oxides: These are iron oxide, aluminum oxide, and zinc oxide. They're formed when the metals being welded convert into gas and react with oxygen in the air.
• Gases: Welding releases gases such as ozone, nitrogen oxides, and carbon monoxide into the air. Moreover, the mix may also include shielding gases like argon, helium, and carbon dioxide, which are utilized to safeguard the welding zone.

Factors that Affect Worker Exposure to Welding Fume

• Type Of Welding Process: This refers to the method used for welding, like stick welding or MIG welding. Different methods produce different amounts of smoke and gases.
• Welding Environment: Where the welding happens matters. If it's indoors with bad ventilation, there might be more smoke. And if it's in a small space, there's less room for the smoke to go.
• Welding Technique: How the welder performs the weld can affect their exposure. If they're directly in the path of the fumes, they might breathe in more fumes.
• Materials and Consumables: What's being welded and what's used to do the welding affect the smoke. For example, welding stainless steel makes smoke with chromium, and welding coated metals can make smoke with zinc.

Health Effects of Breathing Welding Fume

• Short-term exposure to welding fumes and gases can cause eye, nose, and throat irritation, nausea, and, dizziness. Workers experiencing these symptoms should leave the area, get fresh air, and seek medical help.
• Long-term exposure to welding fumes may result in lung damage and increase the risk of developing various cancers, including lung, larynx, and urinary tract cancer.
• Inhaling specific metal fumes, like zinc oxide emitted during the welding of galvanized steel, can lead to a condition known as metal fume fever. Symptoms include fever, chills, headache, and muscle aches, resembling flu-like symptoms.
• Breathing in certain welding fumes, like those containing manganese over time may result in neurological damage. This damage may lead to symptoms similar to Parkinson's disease, such as tremors, difficulty moving, and problems with thinking.
• Helium, argon, and carbon dioxide gases can reduce oxygen levels in the air, increasing the risk of suffocation, especially in confined spaces during welding. The formation of carbon monoxide gas presents a serious risk of asphyxiation.

Reducing Exposure to Welding Fumes

Ventilation System

• Local Exhaust Ventilation (LEV): This system captures fumes right where they are produced before they can spread. For example, a hood placed near the welding area can suck up the fumes directly, preventing them from reaching the welder's breathing zone.
• General Ventilation: Improves the overall airflow in the workspace to dilute and remove fumes. Using fans and exhaust systems to keep air moving can help disperse fumes and reduce their concentration in the air.

Respiratory Protection

When ventilation alone isn't enough, welders should wear respirators. These can be air-purifying respirators, which filter out contaminants from the air, or supplied-air respirators, which provide clean air from an external source. Choosing the right type of respirator depends on the specific welding process and materials used.

Work Practice Controls

• Following proper techniques and practices can effectively reduce exposure to fumes. For example, welders should position themselves away from direct fume contact. Keeping the head out of the fume plume and using a backhand welding technique can help minimize inhalation.
• Keeping the work area clean by regularly removing accumulated dust and residues also helps reduce the production of fumes.

Substitution

Whenever possible, use less hazardous materials or different welding processes that generate fewer fumes and gases. For example, using low-fume welding rods or switching from stick welding to MIG welding, known for its reduced fume emissions, can be effective.

Conclusion

Maintaining a safe work environment requires skillful management of the hazardous fumes and gases emitted during welding. By implementing measures such as proper ventilation, using the right respirators, and choosing safer materials or welding methods, welders and their coworkers can make the workplace safer and reduce health risks related to welding fumes and gases.

Written by: Muntaha Islam