Ketchup stored in a tin can may lead to chemical contamination.

The given statement is True.

Ketchup is acidic, having a pH of 3.9. The acidic component, acetic acid, will react with the metal tin. This reaction will result in a metal acetate that will contaminate the ketchup.

Hence, The acetic acid in the ketchup will react with the metal tin, forming a metal acetate that will pass into the ketchup which leads to its contamination.