Which solvent is a potential source of poisonous fumes when welding if not properly handled?

Which solvent is a potential source of poisonous fumes when welding if not properly handled?

• A. Water-based cleaners
• B. Chlorinated degreasing solvents
• C. Soap
• D. Alcohol-based cleaners

Answer: (B)

When you weld, heat from the arc can vaporize any solvent left on the surface. Chlorinated degreasing solvents are especially dangerous because their chlorine-containing molecules can decompose under the high heat into toxic gases like phosgene and hydrogen chloride. Phosgene is a highly poisonous gas, so even small amounts can pose serious health risks to anyone nearby. That’s why these solvents require extra caution: remove them completely or replace them with non-chlorinated cleaners before welding, and ensure good ventilation. Other cleaners like water-based products, soaps, or even alcohol-based cleaners don’t form phosgene in typical welding conditions, though alcohol-based cleaners still pose flammability and fume considerations. The key is to avoid chlorinated solvents in the welding area and clean surfaces with safer methods.

When you weld, heat from the arc can vaporize any solvent left on the surface. Chlorinated degreasing solvents are especially dangerous because their chlorine-containing molecules can decompose under the high heat into toxic gases like phosgene and hydrogen chloride. Phosgene is a highly poisonous gas, so even small amounts can pose serious health risks to anyone nearby. That’s why these solvents require extra caution: remove them completely or replace them with non-chlorinated cleaners before welding, and ensure good ventilation. Other cleaners like water-based products, soaps, or even alcohol-based cleaners don’t form phosgene in typical welding conditions, though alcohol-based cleaners still pose flammability and fume considerations. The key is to avoid chlorinated solvents in the welding area and clean surfaces with safer methods.