Sweller refers to which condition in canned goods?

• A. One or both ends is distended
• B. Rust that cannot be removed with a soft cloth
• C. Flat sides on the container causing two or more ridges
• D. A dark discoloration on the interior of the can body as a result of high acid reacting with the tinplate

Answer: (A)

Gas buildup inside a sealed can pushes outward on the ends, causing distension or bulging. This swelling, often called a sweller, directly indicates that the can’s internal environment has been compromised and microbes may be growing, producing gas. That core idea—bulging ends signaling potential spoilage and safety risk—makes this the best indicator among the signs listed.

Other signs describe different issues: rust that won’t come off with a soft cloth signals corrosion, not gas pressure; flat sides with ridges point to physical denting or deformation, not internal gas; and a dark interior discoloration from high acidity reacting with tinplate shows chemical interaction, not internal gas production. These do not indicate a can is swollen from gas, so they’re not the same as a sweller.