Which metal is used for tin-plating for steel food cans against corrosion?

• A. Tin
• B. Zinc
• C. Lead
• D. Copper

Answer: (A)

Coatings for steel cans must provide a strong, food-safe barrier that stops corrosion from moisture, air, and the contents themselves. Tin is the best fit because it forms a thin, continuous, inert surface on steel that resists oxidation and doesn’t react with most foods. This creates a stable barrier between the steel and the interior contents, preventing rust and extending can life, while also being safe for contact with food.

Other metals don’t fit as well for different reasons. Zinc is highly reactive and would corrode more readily in acidic foods, potentially affecting taste and safety. Lead is toxic and unsuitable for anything that contacts food. Copper can react with acidic foods and is more expensive and less stable as a food-contact coating. Tin, therefore, provides the right combination of corrosion resistance, safety, and workability for steel food cans.