Which item is NOT solid waste produced by welders?

Which item is NOT solid waste produced by welders?

• A. Filtered air from an environmentally friendly exhaust
• B. Metal shavings
• C. Used oil
• D. Scrap metal

Answer: (A)

The main idea is that waste types in welding differ by state: solid waste, liquids, and gases. Metal shavings and scrap metal are physical solids left over from cutting and grinding, so they’re clearly solid waste. Used oil is a liquid waste that carries contaminants and requires proper hazardous waste handling. The filtered air from an exhaust, however, is a gas—air that’s being moved or vented, not a solid residue. Even when filtered, it isn’t a solid byproduct, so it isn’t solid waste. Therefore, the item that isn’t solid waste is the filtered air from the exhaust.

The main idea is that waste types in welding differ by state: solid waste, liquids, and gases. Metal shavings and scrap metal are physical solids left over from cutting and grinding, so they’re clearly solid waste. Used oil is a liquid waste that carries contaminants and requires proper hazardous waste handling. The filtered air from an exhaust, however, is a gas—air that’s being moved or vented, not a solid residue. Even when filtered, it isn’t a solid byproduct, so it isn’t solid waste. Therefore, the item that isn’t solid waste is the filtered air from the exhaust.