A potential source of poisonous chemical fumes when welding is:

A potential source of poisonous chemical fumes when welding is:

• A. Carbon dioxide extinguishers
• B. Inert shielding gases
• C. Chlorinated degreasing solvents
• D. Anti-spatter nozzle sprays

Answer: (C)

Chlorinated degreasing solvents can release highly toxic fumes when they are heated by the welding arc. The heat decomposes the chlorine-containing solvents and can produce gases such as phosgene and hydrogen chloride, which are dangerous to breathe and can cause severe lung damage. That safety risk is why these solvents must be removed and replaced with safe cleaners before welding, and proper ventilation should be used. The other options don’t pose the same poisonous-fume risk in typical welding scenarios: inert shielding gases are nonreactive and don’t generate toxic fumes, carbon dioxide extinguishers aren’t a source of welding fumes, and anti-spatter nozzle sprays may contain solvents but are not known for producing the highly poisonous fumes associated with heated chlorinated solvents.

Chlorinated degreasing solvents can release highly toxic fumes when they are heated by the welding arc. The heat decomposes the chlorine-containing solvents and can produce gases such as phosgene and hydrogen chloride, which are dangerous to breathe and can cause severe lung damage. That safety risk is why these solvents must be removed and replaced with safe cleaners before welding, and proper ventilation should be used. The other options don’t pose the same poisonous-fume risk in typical welding scenarios: inert shielding gases are nonreactive and don’t generate toxic fumes, carbon dioxide extinguishers aren’t a source of welding fumes, and anti-spatter nozzle sprays may contain solvents but are not known for producing the highly poisonous fumes associated with heated chlorinated solvents.